Aberrant. Atypical, departing from the normal type or structure. Abiotic. The absence of living organisms. Abrasion. Wearing away of surfaces by friction. Absolute pressure. Atmospheric pressure plus gauge p ressure. Absorbed dose. The amount of a chemical that en ters the body of an exposed organism. Absorbed water. Water held mechanically in a soil ma ss and having physical properties not substantially differen t from ordinary water at the same temperature and pr essure. See adsorbed water. Absorption. Taking in of fluids or other substances< /NP> through, or as if through, cells or tissues. Th e uptake of water or dissolved chemicals by a c ell or an organism (as tree roots absorb dissolved nutrients in the soil). Should not be confused with adsorption. Absorption factor. The fraction of a chemical m aking contact with an organism that is absorbed by t he organism. Abutment. That part of the valley wall against which the dam is constructed. The part of a dam that contacts the riverbank. A structure that supports the ends of a dam or bridge. An ar tificial abutment is sometimes constructed, as a concrete gravity section, to take the thrust of an arch dam where t here is no suitable natural abutment. Action or plac e of abutting; the part of a structure that is the terminal point or receives thrust or pressure. Defined in terms of left and right as looking a way from the reservoir, looking downstream (i.e., left abutme nt, right abutment). Acceleration. In terms of flow, acceleratio n is the time rate of change of the velocity ve ctor, either of magitude or direction or both. Accelerogram. The record from an accelerometer showing acceleration as a function of time. Acceptable daily intake (ADI). Estimate of the largest amount of chemical to which a person ca n be exposed on a daily basis that is not anticipated to result i n adverse effects (usually expressed in mg / kg / day). Access control point. A location staffed to restrict entry of unauthorized personnel into a risk area d uring emergency and/or disaster events. Access contr ol is normally performed just outside of the risk area and i nvolves use of vehicles, barricades, or oth er measures to deny access to a particular area. Access shaft. Concrete portion of an outlet wor ks between the shaft house and the gate chamber. The access shaft provides vertical access to the gates . Accident assessment. The evaluation of the nature, severity, and impact of an accident. Da m operating personnel are primarily responsible for accident asse ssment for incidents at Reclamation dams. Acclimation. Adjustment of an organism to a new habitat or environment. Accretion. Process of growth whereby materi al is added to the outside of nonliving matter. The gradual increase in flow of a stream attributa ble to seepage, ground water discharge, or tributary inflow. Accuracy. How closely an instrument measures the tru e or actual value of the process variable being mea sured or sensed. Acid. A substance that has a pH value between < NP>0 and 7. Acid rain. Precipitation which has been rendered acidic by airborne pollutants. Acidic. The condition of water or soil which contains a sufficient amount of acid substances t o lower the pH below 7.0. Acidified. The addition of an acid (usually nitric or su lfuric) to a sample to lower the pH below 2.0. Acre. Unit for measuring land, equal to 43,560 sq. ft., 4840 sq. yds., or 160 sq< /NP>. rds. Acre-foot. A term used in measuring the volume or amount of water needed to cover 1 acre (43,5 60 square feet) 1 foot deep (325,851 gallons or 1,233.5 cubic meters). Activated carbon. Adsorptive particles or granules of carbon usually obtained by heating carbon (such a s wood). These particles or granules have a high capacity to selectively remove certain trace and soluble ma terials from water. Active capacity. The reservoir capacity normally usable for storage and regulation of reservoir inflows to meet established reservoir operating requirements. It extends from the highest of either the top of exclusive flo od control capacity, the top of joint use capacity, or the top of active conservation capacity, to the top of inactive capacity. It is also the total capacity less the sum of the inactive and dead capacities. The reservoir capacity that can be used for irrigation, power, municipal and industrial use, fish and wildlife, recreation, water quality< /NP>, and other purposes. Active conservation capacity (active storage). The r eservoir capacity assigned to regulate reservoir inflow for irrigation, power, municipal and industrial use , fish and wildlife, navigation, recreation , water quality, and other purposes. It It not include exclusive exclusive flood control joint joint us e capacity It It from the the top the the activ e conservation capacity the the top the the inactive cap acityor dead dead capacity there is no no inactive capac ity. Active Active fault A A fault, because of its its present tectonic setting can undergo movement movement time time time time the the immediate geologic fut ure A A fault which has moved during the the recent past (QuarternaryQuarternary and, thus, may move again. It I t or may not generate earthquakes. earthquakes capable c apable fault Active Active transport An An energy-expending mechanism which a a cell a a chemical the the cell membrane a a point lower lower concentration a a point higher higher concentration against the the diffusion grad ient Acute. Acute over a a short period timetime use d to describe brief brief exposures effects effects appe ar promptly after exposure. exposure Acute exposure A A single exposure a < NP>a toxic substance results in severe severe biological harm death. death Acute exposures usually characterized as lasting no longer than a a day Acute Acute toxicity The The ability a a substance cause poisonous poisonous effects in severe severe biolog ical harm death death after a a single exposure dos e. dose, any any severe poisonous effect from a a si ngle short-term exposure a a toxic substance Adaptation. Adaptation Adjustment environmental envi ronmental conditions Additive Additive effect Combined effect effect two two more more chemicals to the the sum their th eir individual effects Adhesion. Adhesion resistance resistance soil soil another another material zero zero applied pressure. pressure. Adit A nearly horizontal underground excav ation an an abutment an an opening only only on e end An An opening the the face a a dam a ccess access galleries galleries operating operating chambers Adsorbate. Adsorbate The material removed by the the adsorption process Adsorbed Adsorbed water Water Water a a soil ro ck rock mass held by physico-chemical physico-chemical forces having physical physical properties different from absorbed water water chemically combined water, water the th e same temperature pressure. pressure. Adsorbent The materialfor example example carboncarbon that is responsible for removing the < NP>the undesirable substance the the adsorption process Adsorption. Adsorption The process which chemicals c hemicals held on the the surface a a mineral soil < NP>soil particle The The adherence a a gas liquid, or dissolved material material the the surface a a s olid An An increase concentration concentration gas gas solute solute the the interface a a tw o-phase system Should not be confused with absorption. absorption Advisory Council HistoricHistoric Preserv ation Executive Executive agency for ensuring requirements < NP>requirements National National Historic Preservation Act 36 36 CFR Part 800 met. Visit Visit the Advisory Cou ncil HistoricHistoric Preservation web site Aeolian (eolian). Materials Materials, deposited, produced, or er oded by the the wind Aeolian Aeolian deposits WindWind deposited material material as dune dune sands loess loess deposits Aerate. Aerate impregnate with gas, gas air. Aeration. Aeration The process adding air air w ater by by either air through water water passing water water air. air Aerial cover Ground Ground area by the the perimeter the the branches leaves leaves a give n plant plant group group plants plantsgenerall y used as a a measure relative relative density. Aerobic. Aerobic A condition which free (atmospheric) or dissolved oxygen oxygen present in water. water The opposite anaerobic. anaerobic environment. environment biological, physical, social, and economic economic conditions an an area to change, both both directly indirectly, as the the result a proposed human human action Also, the the chapter an an environmental impact statement current current environment al conditions Afterbay Afterbaytailracetailrace. The The body water water downstream from a a powerplant pumping plan t. plant A reservoir pool pool regulates fluctu ating discharges discharges a a hydroelectric power plant a pumping plant. plant Afterbay damreregulating damdam. A A dam downstream from a a large hydroelectric powerplant to re gulate discharges discharges. See regulating dam. dam Age tankday day tank. A A tank to store a a chemical solution known concentration concentration feed feed a a chemical feeder Aggradation. Aggradation Geologic process streambeds, streambeds, floodplains, sandbars the the bot tom water water bodies raised in elevation elevation the the deposition sedimentsediment the the opposi te degradation. degradation. Aggregate rock rock gravel gra vel to sizes sizes use use road road surfaces concrete, or bituminous bituminous. A A mass cluster cluster soil soil particles often having a a charac teristic shape Agricultural Agricultural drainage The The process direc ting excess excess water from root root zones natural natural or artificial means such as by using a a system pi pes pipes drains placed below ground ground surface levelalso called subsurface subsurface drainage. The The water away from irrigated farmland. farmland. Agrochemical Synthetic chemicalspesti cides pesticides fertilizersfertilizers used in agricult ural agricultural production Air Air quality Measure Measure the the health-relat ed visual visual characteristics the the air often derived from quantitative quantitative measurements the the c oncentrations specific specific injurious contaminating subs tances. substances Air release valve A A valve usually manually operated, which is used to release air air a a pipe< /NP> fitting. AirAir slaking The The process breaking up or sloughing when an indurated soil soil exposed to air. Airspace Airspace ratio Ratio Ratio volume volume water water can be drained from a saturated soil soil rock rock the the action force force gravity < NP>gravity total volume volume voids. voids Air-void ratio The The ratio the the volume airspace airspace the the total volume voids voids a a soil mass. Air waves Air Air vibrati ons vibrations by explosions. explosions (Automated Automated Local Evaluation RealReal Time. A A flood warning system of remote remote se nsors data data transmission radio, radio a a c omputer software package by the the National Weather Service NWSNWS. Also, a a generic term for a a decision software software package Alevin. Alevin A young fish has not yet absorbed its its yolk sac Algae. Algae Simple plants chlorophyllchlorophyll most live submerged in water. water Microscopic plants contain chlorophyll and live floating or suspended in water. water They may be attached to structures, structures r ocks other other submerged surfaces They They food food fish fish small small aquatic animals Exce ss Excess algal growths impart tastes tastes odors o dors potable water. water Algae oxygen oxygen sunlight sunlight hours use use oxygen the the n ight hours Their Theirbiological activities affect the the pH dissolved oxygen oxygen the the water Algae Algae bloom A A heavy growth algae algae and on a a body water water a a result high high phosphate concentration farm farm fertilizers detergen ts. detergents Algal bloom Rapid Rapid and flourishing g rowth algae. algae, massive massive growths microsc opic microscopic and macroscopic plant life such as green gre en bluegreen bluegreen algae which develop in lakes lake s reservoirs. reservoirs. Algicide Any substance chemical chemical formulated to kill or control algae. algae. Aliquot Portion a a sample Alkali. Alkali A soluble salt from the the ashes plants. plants A substance marked basic basic prop erties Various Various soluble salts principally of sodium, sodium, potassium, magnesium calcium, calci um have the the property combining with acids acids form neutral neutral salts may be used in chemical chemical water treatment. Alkali-aggregate Alkali-aggregate reactionAARAAR. A A deterioration concrete concrete which the the alkali the the cement paste the the concrete reacts with th e the silica carbonate present in some some aggregates I n the the presence free free moisture the gel the ge l of product reactionthe reaction expand and manife st into cracking and differential movement differential movement as structures as other deleterious other deleterious effects< /NP> reduction in reduction durability freeze-thaw durability and compressive strength. tensile strength Thr ee forms reaction alkali-aggregate reaction identified, see alkali-silica reaction, alkali-silica reactionthe slow / late -expanding type referred reaction as alkali-silicate reactio n, alkali-silicate reaction alkali-carbonate the alkali-carbo nate reaction the Visitthe Alkali-Aggregate Reactions database reaction Alkali-carbonate reaction). ACR o f Reaction which alkalis between certain argillaceous certain argillaceous dolomitic limestones alkaline the alkaline pore solution concrete the concrete expansion causes ex pansion cracking. Expansive dolomite Expansive dolomite limestone s by a matrix a matrix calcite fine calcite mineral s clay minerals dolomite scattered dolomite rhobohedra r eaction This reaction early and early and structures cra cking within 5 years 5 years. See construction reaction. alkali-aggregate reaction Having Alkaline pH a pH or 7.0. The condition The condition or water which soil a sufficient a sufficient amount substances alkali substances the pH the pH. The 7.0 Th e quality bitter due bitter due content. Alkali-silica content Alkali-silica reaction). ASR of Reaction with alkalis with aggregate for ms various forms crystalline poorly crystalline reactive sili ca, chert, opal chert flint and chalce dony tridymite, also tridymite crystoblite glasses. volcanic glasses such materials such materials, some e.g. some cherty gravels cause deterioration of deteri oration when present in amounts of amounts% 1 %%. < NP>5 % Concrete these aggregates these aggregates b y the early the early onset relatively a relatively rapid exp ansion of structures is structures observed within 10 years 10 years. See construction reaction. alkali-aggregate reactionAlkali-silicate / silica reaction). ASSR of Reaction with alkalis quartz is quartz to be one reactive one reactive component causing < NP>aggregates reaction. this reaction A wide variety rocks quartz-bearing rocks found to be reactive including grayw ackes, argillites, graywackes, argillites, quartzwac kes, quartzarenites, quartzites hornfels, quartz biotite granite, gneiss, granite phy llite arkose. This sandstone This type is reaction by a delayed onset of onset and expansion may not become evident for up to 20 years 20 years. See c onstruction reaction. alkali-aggregate reaction Influence Allelopathy Infl uence upon plants other each other products of products, e.g., metabolism e.g. creosote bushes toxic a toxic substance the growth the growth plan ts other plants immediate the immediate vicinity. Exotic Allochthonous Exotic species given a given area refers to deposits of deposits that ma terial elsewhere, e.g., drifted e.g. material plant mate rial bottom the bottom lake. a lake Having Allopatric and separate and mutually e xclusive areas distribution. geographical distribution Allowable pile bearing load ma ximum The maximum load be permitted on a pile a pile saf ety adequate safety of movement magnitude such magni tude structure the structure. Alluvial. Related Alluvial, composed of, or found in alluvium. Se dimentary alluvium Sedimentary material deposited by the action the action water, such water in a riverbed, floo d plain, flood delta. Alluvium. delta Alluvium Material deposited by flowing water, such water clay, silt, clay, silt sand. Soil, gravel Soil the constituents< /NP> have been transported in suspension by suspension water and water deposited by sedimentation. A sedimentation bed of bed, gravel, sand, gravel silt deposi ted clay flowing water. Alternating water (AC). AC electric An electric reverses its direction itsdirection/positive / nega tive values regular intervals. regular intervals current. direct current Courses Alternatives Courses tha t action meet the objectives the objectives proposal a proposal levels of levels, including accomplishment most the most likely future conditions project the projec t. Ambient. action Ambient conditions natural condition s at environment given place and place. Environment al time Environmental or conditions Ambient temperature. Ambient temperature Temperature sur rounding air (air other mediumother medium Ambursen dam. Ambursen dam A buttress dam the upstream < NP>the upstream part relatively a relatively thin flat slab of reinforced concrete. Ammonium. One Ammonium One form that nitrogen u sable by plants. Amperage. plants Amperage The strength electric an electric current amperes. The amperes The amount current electric current flow to the flow the flow in water per gallons (minute). gpm. A Ampere A unit current electric curre nt of rate of flow. One electrons One volt ohm 1 ohm causes resistance current a curr ent flow ampere. 1 ampere Based Amperometric the electric the electri c current between two electrodes two electrodes solution. a solution Vertebrate animals Vertebrate animals life st ages life in both in water land (land, salamand ers, e.g., salamanders frogs). toads c apable Animals living either living water or water. Amplification. land Amplification Modification input the input bedrock ground motion overlying unconsolidation m aterials. unconsolidation materials Amplification amplit ude the amplitude surface the surface ground motion incr eased in some range some range and frequencies in others . Amplification others Amplification function a func tion shear the shear wave velocity of the unconsolidated the unconsolidated materials thickness its thickness, and geometry strain the strain level input the i nput rock motion. Fish Anadromous Fish from salt water sa lt water to breed. Going up rivers to rivers. Anaerobic. A Anaerobic A condition free (atmospheric) or dissolved oxygen is oxygen present in water. The water The opposite. Anchor block. Anchor thrust block. thrust block Angle friction external friction o f angle frictionwall friction Angle between Angle abscissa the abscissa tangent the tangent curve t he curve relationship the relationship resistance to res istance stress normal stress soil and soil of s urface material. another material Angle friction internal friction of angle resistanceshear resistance The angle The angle axis the axis stress normal stress tangent < NP>the tangent Mohr the Mohr envelope point a point given failure-stress condition failure-stress condition material . solid material Angle. The obliquity The ang le direction the direction resultant the resultant stres s acting force a given plane and plane normal t he normal plane. that plane Angle. Angle repose Angle h orizontal the horizontal maximum the maximum slope soil a soil natural processes. natural processes granular dry granular soils effect the effect height the height< /NP> is slope; for cohesive soils, cohesive soils th e effect of height is slope great that the angle the angle is repose. Angler-day. The Angler-day The time by fishing person one person part any part day. a day A Anion A negatively in ion elec trolyte an electrolyte solution to the anode under the influence the influence difference a difference potential. ele ctrical potential. Anisotropic cationAnisotropic mass. A mass properties different properties directions different directions given point. Anisotropy. point Anisotropy Flow conditions di rection. Most direction Most aquifers. Annex (Annex). An emergency An emergency operations that element the jurisdiction's the jurisdiction 's plan that component that component area during activity . Annual emergencies Annual failure probability probabilit y The probability load the load the probability the probability. Annualized failure of loss. The life The su m probability the probability failure dam failure t he annual the annual probability loading and the estimated number of number that lives be lost (consequences) consequ ences each dam each dam failure scenario particular a pa rticular loading category (probability of probability)fa ilureprobability of probability)loadpotential loss potential loss)life. Annular. Ring-shaped. Annular space. Annular space A ring-shaped space two circular two circular objects as two pipes. two pipes The Anode The positive pole of el ectrode electrolytic an electrolytic system anode The an ode charged particles or particles (ions). anio ns cathode. Anoxic. cathode Anoxic. Antecedent oxygen. Antecedent flood A flood of series assumed floods occur prior to the occurrence the occurrence inflow an inflow design flood). IDF. Human-created. Anthropogenic. A Anticline in rocks that rocks upward curves a convex a convex way. An Appendix An emergency operations attached < NP>element a functional a functional annex information on information approaches special approaches generated re quirements unique characteristics unique characteristics haz ards specified hazards concern particular concern jurisd iction. the jurisdiction. Application efficiency The ratio average the average depth water irrigation water sto red in the root the root zone average the average depth water irrigation water expressed as a percent. a percent (water water). water delivered Wa ter a user. a user may water used for either inside uses or uses watering. outside watering It inc lude precipitation or precipitation losses. distribution loss es It to metered or unmetered deliveries. unmetered deliveries. Appraisal estimate An estimate an appraisal an appraisal study aid an aid the mos t the most economical plan alternative features alternative f eatures determinimg whether determinimg detailed more de tailed investigations potential a potential project justifie d. Used to obtain approximate costs approximate costs short a short period with time data. inadequate data be us ed for project authorization. project authorization Appraisal level. The detail The level necessary detail facilitate making decision s on decisions or not to proceed with a detailed a detailed s tudy of evaluation alternative. any alternative Appraisal study reportappraisal repo rt A study A study appraisal an appraisal level. Approach detail. Approach channel The channel t hat portion that portion spillway the spillway concrete a concrete lining structure. concrete structure Chan nel intake structure intake structure outlet an outlet Channel is Channel unlined, excavated in rock or soil, ro ck or soil riprap, soil cement riprap soil ceme nt of other types. Appropriation. erosion protection Appropriation Amou nt set water or assigned to a particular purpose a parti cular purpose Appropriative. Water use Appropriative Water rights< /NP> of a ownership supply a water supply for the benefi cial use the beneficial use following water specific leg al a specific legal procedure. Outlet Appurtentant structures spillways, < NP>Outlet, drain spillways, bridges, drain syst ems etc.tunnels towerstowers Apron). fore apron of A section riprap concrete ups tream riprap downstream from a control structure a control st ructure of the structure. A the structure A short ramp pitch. a slight pitch A floor concrete, lining, or other timber material other suitable material of the toe, discharge a dam a side, a a spill way or a chute structure, to protect structure wate rway from the waterway falling erosion or turbulent water. Aquatic. turbulent flow growing, Aquatic occurring in or on the water. Aquatic the water Microscopic Aquatic algae Microsco pic plants sunlit water containing sunlit water nitrates, an d phosphates nitrates. Aqueduct. other nutrients Aqueduct Man-made canal to pipeline water. Aqueous. Something water Aqueous Something, sim ilar to, or containing water; watery. water. A layer Aquiclude A layer limits cla y movement of the movement. Aquifer. ground water Aquifer A water-bearing stratu m, sand, permeable rock. sand water-bearing gra vel A water-bearing formation ground water a ground wate r reservoir geologic Underground water-bearing geologic formation A geologic structure, A geologic formation, gr oup part formations a part that a formation transmits water and yields water quantities of significant quantities wells water springs. wells natural s prings A natural underground layer water-bearing materials ( water-bearing materials gravel) sand gravel of yielding a large amount a large amount water. supply. Suitable water farming. Having soil or topograph ic soil suitable topographic features. Arable land. cultivation Arable land Land in ad equate size units adequate size units climatic and economic c limatic and economic setting with the essential on-farm the essen tial on-farm improvements, leveling, soil vegetation, le veling, soil reclamation drainage facilities, i rrigation generate facilities income under sufficient in come pay irrigation farm production all farm production expenses reasonable return a reasonable return family's the farm family 's and labormanagement and capi tal least pay the least pay maintenance, the operation maintenance of replacement costs and associated irrigation. Arch drainage facilities A concrete dam A concrete which masonry dam upstream in plan so as plan transm it the major part the major part load the water load and the abutments the dam in the dam A solid compressio n A solid concrete dam plan. An arch plan An ar ch dam used in a narrow site a narrow site of steep wall s. See sound rock dam, thin arch dam, medium-th ick arch dam, thick arch dam arch-gravity arch-buttress dam constant arch-gravity dam constant angle consta nt radius dam constant radius double curvature dam double curvature and multiple dam dam. multiple arch damArch-buttress dam buttress dam). A dam dam A buttress dam in plan. Arch-gravity dam. plan Arch-gravity dam An arch dam< /NP> slightly thinner than a gravity dam. a gravity dam American Archaic, a American archeolog y a cultural stage known human occupation in human occup ation World the New World B.C. to A.D. B.C.). A .D. 100 was This stage a generalized hunting and gathering < NP>hunting and seasonal lifestyle to seasonal movement of a advantage of a variety Archeology. Study resources Archeology Study th rough human cultures and the recovery their analysis relics. their material relics An Archimedean screw An ancient water-raising device, made up Archimedes a spiral tube a spiral tube shaft or a shaft large screw a l arge screw, revolved a cylinder. A pump hand A pump inclined, revolving, corkscrew-shaped shaft tightly corkscre w-shaped shaft a pipe. Arching. a pipe of The transfer a stress part o f a part or a soil to rock mass or adjoinin g less-yielding of restrained parts Area-capacity the mass. Area-capacity table giving A table capacity, reservoir storage capacity areas, in terms areas elevation terms. Area elevation increments Area a influence. Are a a well Area within a well piezometric surface the piezometric surface when pumping has produced a maximum stea dy a maximum steady rate Arid. A flow Arid A term or a climate which region is so deficient is quantity or occurs q uantity infrequently that intensive agricultural production inten sive agricultural production without irrigation. Armoring. See irrigation. Arroyo. A riprap Arroyo A gully by channel cut stream. an intermittent stream A water-carved channe l an gulley area, an arid area in cross section wit h cross section, dry steep banks the time due the ti me rainfall and infrequent rainfall of the depth wh ich the cut penetrate below the level of the level water . permanent ground water Water held under Water in porous pressure or porous rock by soil geologic format ions. impermeable geologic formations An artesian flowin g. See confined aquifer. Artifact. A aquifer Artifact. A human-made object Man-made or constructed drains. Artificial recharge. Addition Artificial recharge Addition to surface water water a ground water reservoir, such human activity surface water into surface water. See gr ound basins recharge, ground water recharge. Associated recharge basin A term facility A term to describe Reclamation facilities examined those facilitie s respective regional the respective regional or area of fice include These facilities, distribution, and drainage distribution, small drainage systems, small diversion< /NP> plants and powerplants, plants and powerplants open and closed conduits siphons, small tunnels siphons< /NP>, small regulating reservoirs class waterways bridge s. class B bridges Association of Boards of Certification. An ABC organization An international organization boards which 150 boards operators of the operators waste w aterworks facilities. waste water facilities, visit more information visit. the ABC website similar Asymmetric size, shape, form size shape form parts arrangement opposit e parts of opposite sides, point a line. point pressure. plane Atmospheric pressure Pressure the air, averaged the earth psi at 14. 7 psi, or sea level of 29.92 inches measured me rcury a standard barometer. a standard barometer in Attenuation Decrease th e amplitude waves the seismic waves to distance spreading, energy absorption and energy absorption Attribute survey. Survey to survey Survey important comp onents the important components experience. the recreational experience typical. Atypical. A rotating Auger having a drill threa d a screw thread away from cuttings face. Author's the face This Author 's signature of < NP>the signature or the person primary persons for primary responsibility document. Signature the document Signature by the document(the author signifies s a signifies document a draft document team me mbers and that members had an they to an opportunity the draft. The the draft signature The author 's < NP>signature were considered comments that any critical issu es any critical issues were incorporated factors the doc ument. Authorization. the document Authorization An act of the Congress States the United States of public use to public funds a prescribed action. Automatic generation action Automatic generation control . Computerized AGC system Computerized power system regulatio n generation within a generation area a prescribed area< /NP> changes response transmission changes operational < NP>transmission system operational characteristics. A Auxiliary spillway usually A spillway a saddle or a saddle the depression ri m the reservoir rim a natural or a natural, located away waterway the dam which the dam planned release of exces s release flow excess flood flow of the capacity spillway. the service spillway A control structure. Th e crest is The crest the maximum water the maximum water surf ace elevation-a 100 - year flood specific some other spe cific frequency flood spillway The auxiliary spillway infreq uent use. only infrequent use Any secondary spillway to be operated very infrequently and possibly in anticipation of some ant icipation of some degree or structural damage the < NP>erosion during the spillway Available capacity. operation Available capacity The amount in water soil that the soil to the plants. See the plants capacity. water. The capacity Average. The arithmetic mean The sum divided the values number of the number Average annual values. Average annual runoff area, a specified area the average value amounts annual runoff amounts selected period a selected period represents rec ord hydrologic conditions. average hydrologic conditions Average year water demand water Demand average water conditions average hydrol ogic conditions level of development. level year development. Average year supply The average annual supply development a water development system period. a long period to do with birds. Avoirdupois weight. birds Avoirdupois weight An Engl ish of American system on weights pound of a po und. Axis. 16 ounces Axis A straight line shaft or < NP>a shaft. Axis body dam. Axis vertical dam A vertical plane, appearing as surface line in a line cross < NP>plan, to which section dimensions can horizontal dime nsions. Axis of dam Axisconcretedam. A vertical reference A vertical reference surface upstream face the upstream face o f the top. B the dam. B Back that A pressure water to backfl ow water the water supply the water supply's water a user 's water system pressure a higher pressure wa ter the public water system Material used Backfill Material excava tion, or the excavation of the process. Material suc h refilling Material an excavated trench. Backfill concrete. trench Backfill concrete Concrete excavation in lieu excavation earth lieu. Backflow. earth material Backflow A reverse flow con dition a difference in a difference, which water pressur es to flow water into the distribution system. the distribution system first Backfurrow The first c ut, from a plow slice is the slice undisturbed soil . Backsiphonage. undisturbed soil Backsiphonage A form by backflow negative or a negative pressure within atmospheric pressure system. a water system small, Backwater A small gen erally shallow body little water no little or no current . Stagnant its in Stagnant water stream a small stream Water moved inlet Water held back by a dam, tide, a dam. tide tide Baffle A f lat board deflector, guide plate deflector guid e constructed similar device in flowing water to cause w ater uniform flow more uniform flow velocities energy, and t o energy, guide, or agitate guide flow. Baffle the flowBaffle). One of a One of a s eries designed upright obstructions energy as in energy< /NP> case of the case basin or drop basin. A drop st ructure usually A block, constructed in a channel or a c hannel to dissipate basin energy of the energy at < NP>water velocity. Bailer. high velocityBailer A 10-foot-long 20 - foot-long pipe valve at a valve end. the lower end< /NP> A bailer remove slurry from the slurry or the b ottom of the side as a well being it. Balanced head condition. Balanced head condition The conditio n water pressure the water pressure and the upstream of downstream sides are an objectsuch as an emergency or an emergency). Ball-milling. gate repeated churning The repeated churning ac tion gravel, and cobbles gravel by sand fo rce of the force a water basin or other basin b y other structure concrete abrasion severe concrete abrasion< /NP> Bank full. An Bank river stage at river stage location a long a location which a river to represent the maximum s afe the maximum safe water level overflow the not overflow the river banks significant damage any significant damage< /NP> reach. the river reach Water Bank storage Water from a reservoir into a reservoir land where it land in it until water storage in water level is the rese rvoir Barrage (gate-structure Barrage). gate-structure dam bui lt A barrier river, comprising a river of a series when gates open allow fully open to the flood appreciably increasing the flood level the flood level barrage . Bascule the barrage See Bascule gate. Base. flap gate Base A substance pH value a pH value 14. 7 course. 14 Base course A layer selec ted material of planned material constructed on thickness subgrade or the subgrade the subbase of the purpos e or more one such more functions load, providing d rainage, load frost drainage, etc.frost action< NP>frost action Base flood The flood perce nt a one percent chance or exceeded in any given year. This term year This term the National Flood the National Flood Insurance Program to NFIP the minimum level the minimum level be flooding by a community in a community pl ain its flood plain management regulations plain. Base flood plain The flood the 100-the 100 - year flood. Ground Base flow Ground water inflow. P ortion the river Portion that stream derived fr om natural storage. Base natural storage Base safety condition. The BSC< /NP> of The level which a dam failure a dam failure an i ncremental loss an incremental loss Base width life Base width The maximum thickness The maximum thickness a width measured a dam upstream and downstream upstream and downstream faces the axis or the axis of centerline crest, but the dam for outlets projections other outlets structures. other appurtenant structures The base thickness cantilever the crown cantilever dam. an arch dam the term thickness th e term thickness gravity or arch gravity, and width dams used width is dams. Baseline other dams Baseline alternativecondition. Conditions alternative would Conditions if no action s were no actions See future without. Baseline profile. Used Baseline profile survey of a survey conditions the environmental conditions in organisms region prior a region disturbances. Baseload. Minimum disturbances Baseload Minimum load system a power system period a given period Baseloading. Running time through a water at a power plant steady a roughly steady rate power thereby produci ng power rate. a steady rate Powerplant Baseload plant Powerplant carry baseload; consequently, baseload operates essentially < NP>it a constant load. a constant load. Basin runoff model Any one pro grams the computer programs basin mathematically models forecast characteristics inflow from reservoir inflow/rainfall streamflow data. Batter. streamflow data Batter Inclination. A < NP>the vertical A pile angle to an angle area of the area to support thrust. Beaching. The thrust of The action by water waves materials settle beach materials water because the water of finer removal. Bear-trap finer materials Any Bear-trap gate Any of< /NP> a family consisting crest gates leaves, an two leaves an upstream leaf at the upstream edge the upstrea m edge leaf a downstream leaf on its downstream edge. it s downstream edge The two leaves seal at their seal. When their juncture leaves are the leaves horizontal position. a horizontal position Gate ad mitting water from the water into the forebay beneath the space. Probably the leaves gate the first gate principal of the principal headwater application. Bed headwater pressure Height Bed elevation Height a specified level. Bed layer. level Bed layer, The flow layer several grain diameters taken as two grain diameters two grain di ameters immediately above the bed. Bed the bed Sediment Bed load Sediment rolling moves sliding along the bed and the bed in contact with the contact in the bed layer. the bed layer The Bed-load of The quantity pass ing bed load section a cross section in a stream of a unit Bed material. time Bed material or Unconsolidated ma terial, of sediment mixture streambed is composed. Bed-material discharge. That Bed-material of That part s ediment the total sediment composed of is sizes found grain sizes bed. The the bed The bed-material equ al is the transport capability the transport capability. Bedding. the flow or layer Ground such, layer s upport purposes on support purposes is laid. pipe placed beneath Soil beside a pipe to a pipe load on the lo ad. Bedding the pipe A Bedding plane A separation t wo weakness of two layers caused by rock during the changes up the building rock-forming material. the rock-forming material sediments Bedload Coarse s ediments the bottom of the bottom. Bedrock. a river Bedrock The solid rock or the surface surface materials. other surface materials R ock thickness relatively great thickness its extent location. its native location A general term r ock, any solid rock properties, that soil-like properties or underlies soil surficial other unconsolidated surficial materials from boulders. The consolidated boulders The c onsolidated body mineral natural solid mineral matter overbu rden soils. the overburden soils The solid rock soil, sa nd, all soil gravel, sand clay gravel materials other loose materials's surface. the earth 's surface, Any sedimentary material represented metamo rphic material unit in a unit being geology sound a nd a sound, layer, solid mass layer mineral ledge; mineral matter shear wave velocities shear wave< /NP> 2500 feet per 2500 feet Behavior. Reaction second Behavior Reaction to an animal. Bell. its environment, Bell enlarged, end of a pipe section, a pipe section next pipe the next pipe spi got. Bench. A spigot Bench or step level a step< /NP>. Bench a cutBench mark. A BM or A permanent< /NP> of temporary monument above sea elevation, used sea level control at vertical control site. a construct ion site A point assumed elevation used as elevation reference in a reference elevations. A other elevations A permanent reference point used elevation a survey. Bend. a survey Bend A change piping. direction ratio. The Benefit-cost ratio The ratio value the present value to project benefits value the present value costs, the project costs analysis. Beneficial economic analysis Water Beneficial use Wa ter loss the use of the betterment e.g. irrigation society e.g. irrigation. See municipal use. Beneficiary. consumptive use, Beneficiary, Any indiv idual entity (governmental agency State, or Federal State that Federal from a benefits project. a Reclamation project of Benthic, Bottom, or riverslakes organisms oceans live organisms the bottom of the bottom. Bottomwater bodies Bot tom. Benthos. Organisms living Benthos Organisms on the botto m of the bottom, pond, a lake stream, pondo cean streamstream A Bentonitic clay A clay content a high content montmorillonite, th e mineral montmorillonite high swelling on wetting. Berm. A horizontal Berm A horizontal strip into shel f embankment or an embankment break the continuity of th e continuity, usually the slope purpose of the purpose or to erosion the thickness of the thickness at the embankment of a point a change or a slope surface elevation. water surface elevation A horizontal s tep profile of an profile dam. an embankment dam A shelf continuity of the continuity, or a slope of artificial ridge A ledge earth A ledge as al ong shoulder edge of the edge or a road An arti ficial canal An artificial ridge Biennial. Plant earth Biennial Plant during its seeds year its second year. Binder (soil Binder). soil binder soil Portion a soil 40 a No. 40 United States standard sieve Scientific Binomial .. Scientific name pl ants which animals two parts. two parts a genus species a species name. The Bioaccumulation The intake of retenti on substances nonfood substances living organism from or ganism environment, its environment a build-up a build-up substances the substances organism. the organism Test Bioassay Test the effect the effect chemical a chemical living organism. Bioassimilation. organism Bioassimilation The accumu lation substance a substance habitat. a habitat. Biological diversity Number of k inds per organisms area unit area; volume composition the composition in species given a given area given time. Biological time. Biological growth The activity of growth and any and organisms. Biological organisms Biological magnification). biom agnification by Step concentration step concentration in substances levels successive levels chains. fo od chains The enhancement substance a substance a c ontaminanta contaminant a food a food web the organisms the organisms higher concentrations higher concentrations substance the substance food their. food sources. Biological opinion Document U.S. the U.S. Fish Service Wildlife Service) FWS the National the National Marine Fisheries Service) NMFS as opinion whether a Federal a Federal action to jeopardiz e the continued existence of existence threatened or endangered s pecies or species in result destruction the destruct ion modification adverse modification habitat. critical habitat. Biological processes of, character istic resulting from, the activities the activities organism s. living organisms The Biology The scientific study. Biomass. life Biomass Total mass of amount< /NP> organisms living organisms particular a particular area< /NP>. Biosphere. environment of Portion solid the solid earth liquid earth live. organisms. Plant Biota Plant life animal li fe region. a region. Biotic potential Inherent capacity or ganism an organism and survive, which is pitted is limit ing influences of influences environment. the environment. Biotic pyramid all food all food ch ains arrangements hierarchic arrangements as organisms and eaters in a prescribed a prescribed area by numb ers or numbers biomasses, usually biomasses the form the form inverted an inverted pyramid. Smallest Biotope Smallest geographical unit habitat, a habitat a high a high degree in uniform ity environment the environment plant its plant life, animal life a e.g. stump. Biotype. stump homogeneous Genetically homogeneous population of closely similar closely similar individuals genotypic a genotypic race of group. Bituminous. organisms Bituminous or asphalt. Blade. tar Blade part a part excavator an e xcavator and pushes dirt but dirt not carry it. Blast. it Blast or move rock or rock by soi l of means or explosives explosion. an explosion. A mats A blanket of woven cable o r cable rings placed rings a blast a blast flyr ock. Blockloading. flyrock a consistent a consistent amount p ower electrical power stated a stated period. Blue time. Blue tops Grade stakes indicate tops grade level. grade level The Bonnet The upper portion cover the cover gate a gate valve body soils. Borderline soils Soils the characterist ics the characteristics of two classification the cl assification groups Unified the Unified Soil Classification System. Rotary drilling. Rotary drilling Material Borrow Material one ar ea one area used as fill material fill material area. another area. Generally, areas areas, surface areas< /NP> borrow pits. The pits The area material for mat erial embankment an embankment. Borrow pits. Specific pitsSpecific site) s a bo rrow a borrow area material is material for use. Boulder. use Boulder A rock fragment rounded by weathering or weathering, with abrasion average an average dimension inches 12 inches. will not pass a 12a 12 - inch screen rock A rock too heavy to be lifted readily by hand. Boulderhand. Boulder clay A geological term des ignate glacial drift glacial drift not been subjected to the sort ing action of action and water contains particles from < NP>particles to boulders sizes. Box sizes. Box girder A hollow steel beam squar e a square cross rectangular cross section. Mixed fresh Mixed fresh and salt waters containing Water much too much salt useful to people but people salt less salt water. ocean water. Brake horsepower The brake horsepower pump a pump actual the actual motor input horsepower produce the hydraulic the hydraulic horsepower pump a pump and flow) head into account the account the losses the pump the pump friction, leakage, frictio n leakage horsepower Brake horsepower ratio the ratio horsepower hydraulic horsepower efficiency. Branch. efficiency Branch An addition main the main pipe piping system. Breach. system Breach, A gap hole, rift hole in rupture dama dam a breaka break water stored water a dam a dam through in an uncontr olled an uncontrolled manner. unplanned manner opening t hrough opening dam a dam the reservoir. the reservoi r breach is breach constructed opening. An opening An uncontrolled breach unintentional an unintentional opening uncontrolled discharge from the reservoir. the reservoir. Breach hydrograph A flood hydrograph< /NP> a dam a dam breach. A rock A rock of highly angular, coarse fragments. coarse fragments. Density density Density matur e sexually mature organisms given a given area breeding period. Breeding period. Maximum rate Maximum rate in increa se of numbers of individuals species a species< /NP> under population conditions. optimum conditions. Actual rate Actual rate of increase individuals new individuals given population; < NP>population breeding potential minus potential minus factors Bridge, Class BridgeClass A. A bridge a Federal-aid a Federal-aid highway of Examination type this type is bridge every 2 every 2 years in-depth an in-dept h examination every 6 years, Class BridgeClass B. A bridge on a Federal-a id a Federal-aid highway used by the public. the public Examination type this type is bridge every 3 every 3 years, Class BridgeClass C. A bridge on a Federal-a id a Federal-aid highway be designated as being a private a p rivate bridge operating bridge be gated or closed to the pub lic, the public. British thermal British thermal units). Btu of Quant ity required heat raise the temperature the temperature< /NP> avoirdupois one avoirdupois pound 1 water 1 degree F near 39.2 degrees 39.2 degrees F. Broad-crested weir overflow An overflow structure the nappe the nappe for an appreciable an appreciable length direction the direction. Bucket. flow Bucket A part excavator an exc avator, lifts, and lifts dirt. Buffer dirt (strips strips, filter strips strip s, filter strips). buffers of Strips or gra ss close-growing other close-growing vegetation a waterway < NP>a waterway, stream, ditchstream creek a n intensive an intensive land use area, farmsubdivision farm environment. Humanenvironment modified environment, e.g. environment, e.g. buildings and roads. Se e cities resource. cultural resource A Bulkhead A one-piece unit < NP>steel unit lowered into guides and guides against sea ls frame a frame a water a water passage dam, a dam spillway, conduit spillway object An objec t isolate a portion a portion waterway a waterway, maintenance, examination maintenance. A repair A wall erected partition resist ground or ground pressure. water pressure. Bulkhead gate A gate for tempor ary closure temporary closure channel a channel before < NP>conduit it for it or inspection or maintenan ce closure against closure water when water head the head difference (e.g., for e.g. tunnel diversion t unnel closure Bulking. The increase The increase of volume material a material manipulation. Rock manipulation Rock bulks< /NP> excavated; damp sand bulks sand bulks deposited, as by dumpi ng, because the "apparent cohesionapparent cohesion movement of < NP>movement soil the soil particles a reduced volume. Bureau volume Bureau of Indian Affairs). BIA Bu reau The Bureau of Indian Affairs is to mission the qual ity of the quality to promote life opportunity, and economic opportunity out the responsibility to the responsibility improve the trust assets the trust assets, Indian Ameri can Indians and Indian tribes. BIA Alaska Natives < NP>BIA within an agency Department the U.S. Department. Bureau the InteriorBureau of Land Management. The BL M of The Bureau of Land Management within an agency Department the U.S. Department, administers the Interior acres 264 million acres public lands, America 's p ublic lands Western States. 12 Western States The BLM, diversity, the health diversity the productivity lands the public lands and the use present enj oyment future present and future generations In blasting, Burden distance blasting the distance face the free face row the first row the holes between the distance holes rows to holes face. Apparent the face Apparent burden as the burden the delay pattern. the delay patternButt joint). In pipe, flat ends pip e flat ends do not overlap. Butterfly valve. A Butterfly valve A valve closure that quick closure a circular leaf, a circular leaf form, mou nted on form transverse shaft a transverse shaft bearing s. Buttress two bearings A dam dam A dam watertigh t upstream a watertight upstream part a concrete sloping a co ncrete sloping slab intervals on the intervals side the downstream side of a serieswalls buttresses to walls axis of the axis). the dam can take dams< /NP> forms. See many forms, flat arch-buttress dam f lat slab buttress slab, massive head dam massiv e head multiple arch dam, multiple arch dam buttres s solid head C Cairn. dam C Cairn A pile as stones ma rker. Caisson. a marker Caisson A box in chamber< /NP> work under construction work A structure water A structure is chamber sunk or lowered by digging from the < NP>digging. Used the inside access to the access of the bottom or a stream of other body Camber. The water Camber The extra height crest of the crest to embankment dams the freeboard will the freeboard diminished by foundation settlement or foundation s ettlement. The embankment consolidation The amount different camber each dam and each dam on the amount of the amount and foundation settlement to embankment. Canal. A channel, Canal A channel that conveys water by gravity water farms, gravity, etc.farms mun icipalitiesmunicipalities The Canal headworks The beginning. Canal a canal The Canal prism The shape as the canal cross section. Candidate cross section Plant Candidate species Plan t that animal species for designation candidates en dangered designationin danger of becoming danger) or thr eatened (likely to become endangered), but is undergoing status review by status review Fish the U.S. Fish (Wildlife Service. Capable FWS. An Capable fault An active fault c apable of producing macro-earthquakes and exhibits macro-earthquakes or more one the following characteristics. the following characteristics Movement 1 or Movement the ground surface the ground surface within the past 35,00 0 the past (2years Macro-seismicity 23.5 Macro-seismicity Richter 3.5 magnitude Richter instrumentally determined with reco rds of sufficient records to sufficient precision direct relationship a direct relationship. (the fault A 3 relationship A structural relationshi p fault a capable fault on that movement could one fault expected to cause movement on the movement. (the other Established 4 of micro-seismicity pattern s define micro-seismicity fault, with a fault that historic macro-seismicity be associated with that fault. Capacity. that fault Capacity, the power terminology the load generator, transmission a generator or transmission line rated, system is kilowatts. The maximum kilowatts The maximum load, station, a machine station carry system existing service conditions. Equiva lent service conditions peak Equivalent terms peak p eak capability firm peak generation, firm peak load In transmission, capability maximum transmission th e maximum load a transmission line carrying. See excess capa city and excess capacity. Also refers capacity powerplan t generation capability under generation capability conditions specific operating conditions of the amount under mark etable resource. Capillary such conditionsCapillary action. The capil larity or The rise water movement the water of the interstices or a soil to capillary forces. The process forces The process rises through water rises sediment or rock sediment by soil cohesio n between the cohesion and water molecules between a n adhesion other water that other materials water u pward. the water of A property that surface tension< /NP> upwards. See water upwards. Capillary capillary movementCapillary attraction). c apillary force of The tendency move water fine spac es, as fine spaces particles, regardless soil particles. Capillary forces. gravity Capillary forces The molec ular forces movement of the movement very water spa ces. very small spaces. Capillary fringe zone The zone water the free water elevation is held water capillar y action. The capillary action The porous material water table the water table water by capillarity water the capillarity void the smaller void spaces. The Capillary head expressed The potential< /NP> of water, head causes water water to the water< /NP> capillary action. Capillary capillary actionCapillary migration). capi llary flow of The movement capillary water. Capillary capillary action Movement Capillary movement < NP>Movement in underground water capillary response . See capillary attraction. Capillary capillary action The Capillary rise The he ight water a free water elevation will rise water c apillary action. Capillary capillary action Underground Capillary water < NP>Underground water water table the water table. Water capillary attraction Water influence of the influence. Capital capillary action Costs Capital costs Costs debtusually long-term debt construction and financing con struction Capital costs equipment Capital costs, on e-time expenses which one-time expenses of the independent of the amount. All water implements, equipment, machi nery and equipment machinery in inventory produ ction of the production services. goods. Any services Carnivore Any flesh-eat ing. Carry predatory organism The quantity of The quantity co ntinues water an inlet. Cartography. an inlet Cartography Art graphical ly science the features of the features's surfacethe Earth 's surface making. Casing. map making lining A pipe lining hole. The materi al hole The material in wells to prevent wells collapse of the collapse of the walls hole, to prevent < NP>hole from entering pollutants well, and the well the pump and the pump Catastrophe. A pipes Catastrophe A sudden causi ng great disaster destruction, or misfortune destruc tion extensive irreplaceable loss cripple activities in an < NP>activities. Catch. an area Catch fishery, a recreational fishery number of the number, whether fish are kept th ey released. Catchment basin. Unit Catchment basin Unit area from an area the drainage water the drainage water stream or one stream of other body Cathode. The water Cathode The negative pole an electrode cell an electrolytic cell The cathode sys tem The cathode particles or ions particlescations< NP>ions. See cations. Cathodic protection. anode Cathodic protection An el ectrical system rust, prevention, and rust corr osion metal surfaces which metal surfaces contact with water contact soil. water low-voltage soil A low -voltage current is through a liquid (a liquid or water< /NP> soil in a soil the contact in the metal ma nner that a manner electromotive the external electromotive f orce structure the metal structure concentrates corrosion on auxiliary anodic parts auxiliary anodic parts allowed to corrode instead of letting the structure corrode. the structure corrode positively Cation A positively an ion solution, an electrolyte solution cathode u nder the cathode of the influence in a difference. See electrical potential Caulk. The anion Caulk The material joints. Cavitation. The joints Cavitation The formation in partial vacuums caused fast-flowing water pressures immediately subatmospheric pressures an obstruction or an obs truction Usually accompanied by noise and vibration. noise f ormation vibration The formation cavities voids in cavities liquid due a liquid due temperature tur bulence causes temperature pressure in the pressure of local zones to the liquid the vapor pressure. th e vapor pressure the backside of the backside, water shi p propellers blades water turbines, blades high-vel ocity pumps lines, high-velocity flow lines, depending < NP>similar locations design of the design degree equipme nt turbulence. degree formation turbulence The formation a collapse pocket a gas pocket the bu bble of the blade or an impeller of the gate. The a valve The collapse pocket this gas pocket< /NP> water bubble drives water or the impeller a gat e force a terrific force pitting on the impeller or the impeller. Cavitation gate surface Cavitation loud n oises that loud noises someone is pounding someone the i mpeller or the impeller a gate. The a hammer The attack by surfaces pressures immediately subatmosp heric pressures an obstruction or an obstruction Usually acc ompanied by noise and vibration. noise damage. vibration Cavitation damage D amage vacuums formed partial vacuums liquid by a liquid< /NP> moving a swiftly (solid body propeller) a prope ller wear pit solid surfaces away solid surfaces or e.g. metal. The attack on The attack by surfaces implosion of the implosion water bubbles. Cellular water vapor. Cellular gravity dam dam. hollow gravity dam Unit Celsius temperature. Unit Celsius temperature Degrees 5/9Celsiusx(degrees Fahre nheitx32degrees Fahrenheit - 32. An important Central flyway An important internati onal migration route Centrifugal pump. many birds Centrifugal pump A pump centrifugal force water by centrifugal force of an rapid rotation A pump an impeller A pump fixed on an impeller shaft that is enclosed shaft a casing, a nd having a casing and discharge an inlet As the rotatin g connection whirls the water impeller, centrifugal the water up centrifugal force to force the water through th e the water. The the discharge outlet energy to impe ller imparts energy Certification signature. the water Certification signature Certification signatures persons those of the per sons analysis. These the risk analysis These signatures< /NP>, processes, and Reclamation methodology followed. In req uirements, these signatures verify addition these signat ures the persons qualifications various the persons were various probability estimates purpose of endorsing The purpose to reduce qualifications potential for inappropriate the potential or conflicts, inappropriate estimates lim ited conflicts that might limited qualifications total r ejection of risk total rejection. Certification risk analysis findings Certification signatures spirit of the the spi rit and the risk analysis represented team dynamics document. In other the document any divergent other words critical any divergent views critical issues have bee n captured. factors is a check of the a check responsibi lity to the author 's responsibility the team's thinking . Certified the team 's A Certified water right A Stat e-issued document evidence that an legal evidence has been p hysically application and the water put to the water put The certificate beneficial use priority The certificate type of priority date, type the beneficial use of the maximum amount be water. Verification must be pr ovided Verification the State through a the State by a survey water-rights examiner. Even certified water-rights exam iner Even certified rights review to ensure occasional r eview use. Chamfer. To beneficial use Chamfer an bevel or slope. an edge Natural or corner Channel Natural o r artificial watercourse with a perceptible extent and a definite bed and banks continuously or periodically flowing continuously or water and streams. A Rivers term st reams A general term artificial any natural conveyi ng artificial facility Channel margin deposits. water Channel margin deposits < NP>Narrow sand deposits. Check dam. channel banks Check dam A small dam flow of water the flow in water channel, sediment especially a channel soil erosion. Small barrier soil eros ion Small barrier or other a gully to other sma ll watercourse, minimize channel flow velocity and promote < NP>channel of sediment. Check deposition. A sediment Check structure A structure upstream water surface the upstream water surface flow in the downstream flow Check valve. a canal Check valve Any device or air to fluid through air in only one it. in only one direction A special valve or flap that disc in flap direction of normal the direction is norm al flow when flows attempt to go flows the reverse or opposi te the reverse normal opposite direction A device no rmal flow A device. Water backflow flow pipes Water one direction but any one direction the an y reversal the the flow to the check valve signature. Checked signatures verify signature all signatures estimates, inputs all probability estimates inputs distributions, outputs entered their dis tributions event trees, and that event trees calculations, f igures, any other calculations figures checked. tabl es includes "back-of-the-envelope" calculations performed during the calculations analysis but the risk analysis any place bu t the any place In addition, the report of addition< /NP> the accuracy been computer spreadsheets Chimney drain. A vertical Chimney drain A vertical pervi ous material layer an pervious material facilitate a n embankment drainage of the embankment drainage. Chironomid. the embankment fill Chironomid Group who live their insects stage underwater their larv al stage underwater and about as adults Chipping. Loosening of shallow rock Loosening light shallow r ock air light blasting Chisel plowing. air hammers by a Cropland preparation (< NP>a special that avoids complete inversion of avoids complete in versionas the soil conventional moldboard plowing). conv entional moldboard can leave a plowing cover of a protec tive cover the crop residues that the soil surface and improve infiltration. erosion. The application infiltration Chlorination The application, generally chlorine the purpose of d isinfection, the purpose for disinfection other biologic al or chemical other biological or chemical results controlling t astes coagulation odors). tastes. Portion odors spillway Chute Portio n gate spillway crest the gate the crest struct ure, where the terminal structure flow open - channel fl ow conditions conduit for conveying A conduit at high fr ee-flowing materials lower high velocity Cipolletti weir lower elevations Cipolletti weir. A trapezoidal weir of trapezoidal shape weir which trapezo idal shape of the the sides given the notch of 1 a slope 4 1. Circle of 4. The Circle outer influence The circular outer edge in a depression table by the water table water from a well. water cone a well. Circuit. cone complete influence Circuit Th e complete path, including an electric current or other sour ceapparatus or, other source segment or a specific s egment complete section. Circuit the complete path safety Circuit breaker A s afety device that an electrical circuit the circuit when it the circuit. The it can be The device. Circuit mile. For single Circuit mile power single circuit el ectric power transmission lines equal circuit miles miles or pole geographic miles For double pole miles lines, double circuit transmission lines the number twice circu it miles, pole, or the structure. pole. A geographic miles CisternA small tan k or a storage facility used a storage facility for a home < NP>water farm. a home to farm rain water. Civil Defenserain water State Civil Defense Agency S tate agency responsible for local agency, planning, mitigati on, emergency operations response, planning mitigati on preparedness response hazards. recovery , the all hazards term the more current term is emer gency management agency. Filamentous green alga. Cladophora Filamentous green alga High Clam shell ga te High pressure two gate leaves which two and close over the end of a the end Used for a conduit into air with minimal cavitation air. Class minimal cavitation damage Class). pipe wo rking fittings rating of a pressure rating for a spe cific pipe distribution use which water distribution sys tems surges. This allowances is surges This ter m iron, ductile iron, cast iron, ductile iron a sbestos cement. Clay. some plastic pipe Clay Fine-grained soil of the fine-grained portion be soil to exhibit plasticit y (putty-like propertiesplasticity within putty-like properti es of water a range and that water contents strengt h when air-dry. considerable strength which passes Plastic so il 200 United a No. 200 United States Standard sieve procedure used Clearance A procedu re under tightly controlled discipline, a safe environment discip line a safe environment, or inspection. maintenance repair systematically inspection It equipment from all pertinent equipment hazardous all sourceshydrau lic, hazardous energy mechanical, pneumatic, chemical, etc.) and attaching safety tags or locks safety tags appropriate locks< /NP>. Also, the appropriate controls written it that doc uments isolation statement the equipment isolationalso < NP>the equipment as lockout or tagout). lockout. The tagout of Clearing The removal as all vegetation shrubs, brush, stumps, trees shrubs, brush stumps, branches, roots, down timber. branches grass of weeds The removal all all rubbish material. all other objecti onable material. Average conditions of Climate Average conditio ns a the weather years. a number and years . Climatic macroclimate. Continuous microclimateClimat ic year Continuous 12 - month period climactic cycle a c omplete climactic cycle protection. Gravel Coarse gravel protection Gravel layer upon a a layer to protect the surface surface from deterioration or surface. Coaster deterioration. A erosion Coaster gate < NP>A rectangular gate appearance to construction tractor appearance except the tractor gate in much is same way as the same way gate. a ring seal gate material applied The protective material surface of the outer surface frequently metalwork. a materialcobblestone). A rock cobblestone, usually A rock fragment, with an average dimension between an average dim ension inches3 will 12 inches 12-inch a 12 - in ch screen 3-inch a 3 - inch screen temporary structure Cofferdam A temporary structure of all or part so the construction area p roceed that construction dry. A diversion the dry A diversion cofferdam a a river channel or a pipe A < NP>channel barrier, usually tunnel A temporary barrier constructed around an earthen dike a reservoir a worksite a a reservoir so the worksite a stream dewatered < NP>the worksite water level controlled. See the water level. The mutual attraction dam Cohesion The m utual attraction molecular soil particles forces in mole cular and capillary forces. Cohesion the presence in wat er Cohesionespecially dry) clay of little significa nce in silt or little significance The ability silt a sand The ability to a substance pull itself toget her. itself attraction which itself two Molecular at traction. Cohesionless materials two particles soilCohesionless materia ls Soil materials cohesionless soil unconfined Soil mate rials or no unconfined when little or no strength l ittle or no cohesion when little or no cohesion has little tenden cy Soil stick together little tendency or dry, such as s ands and gravels. Cohesive soil. sands clay gravels Cohesive soil , Predominantly clay grained silt soil that fine together whether particles or sticks. A soil that when unconfined A soil strength when air-dried, and considerable strength significant cohesion when submerged. Cold significant cohesion An unplanned joint Cold joint An unplanned surface hardens before a concrete surface harden s placed the next batch Fresh concrete placed on it Fresh concrete Cold-water fishery. Water or water Cold-water fishery Water an water system for salmonoid an environment Coliform. Organisms common salmonoid fishes Coliform Organisms of humans the intestinal tract the humans' presence animals waste the organisms an presence< /NP> of waste water Collar. The an indicator of pollution Collar The open end. Starting a a drill hole When the hole a drill hole< /NP> to the hole bit from slipping out of the bit it is said to be it. it suspension. A method of sediment Collodial suspension A method turbulence sediment transport) supports wa ter turbulence of movement sediment particles, the weigh t them the sediment particles or being them. Colluvium. A general term applied to Colluvium A general term , usually at the foot of deposits slope and the foot chiefly a slope. Commercial river trip. Trips organized gravity Commercial riv er trip Trips tours for paying companies or custome rs. tours user day. passengers of customers Com mercial user day Amount-commercial use or a 24 - hour period water use. any portion motels, Commercial water u se, office Water, other motels hotels, restaurants office buildings Common other commercial facilities materials excavated instit utions Common excavation All materials Boulders or detached pieces of rock Boulders less than pieces cubic solid rock volume are 1 cubic yard excavation. volume excavation. Common material. common excavation materials excavation Common material All earth materials definition of rock. Community. All the definition a rock Community All members present in a group area species a s pecific a specific area group a specific time see a group a people. Community cohesion. themselves of a unit Community c ohesion Ability unified a community facing a a unified response, an external a problem their e.g.. an external threat Backfill which their sustainabili ty Compacted backfill Backfill by rolling, tamping, or soaking. bulk embankment. rolling which has been Compacted em bankment Embankment by rolling, tapping, or soaking. bulk. To rolling soil dense by Compaction manip ulation. Mechanical soil which increases mechanical manipulat ion Mechanical action the voids the density materia l. See the voids dynamic compaction, a material ponding, puddling, rolling, dynamic compaction sluicing, surface vibratio n, and rolling. saturation sluicing surface vibration curve, mo isture-density Compaction curve. The Proctor curve m oisture-density curve between The curve density the rela tionship water the dry density soil the water content compactive a soil Comprehensive Facility Review (compactive effort. Comprehensi ve Facility Review on CFS highA review significant- hazard dam a high years which significant-hazard dam every 6 years a state-of-the-art a field examination struct ure's a state-of-the-art review construction practices, a str ucture 's design assumptions construction practices A integrity examination various loading conditions A detailed examination dam engineer. dams facility a sen ior dam engineer Comprehensive facility reviews by a periodi c every 3 years Compressibility. Property a periodic facility review Compress ibility Property to a soil volume its susceptibility to load. Computer volume station. Computer equipment that Computer bas e station Computer equipment from the data collection platfo rms data translate the data collection platforms informa tion for the data makers. useable information path. the decision makers avenue flow path seepage. The hypothetical avenueconcentrated" seepage The descriptor to carry/move sufficient energy< /NP> erode. Energy / move material type, construction Energy< /NP>, geology, etc., material type construction methods geology in higher an anomaly to materials than highe r velocities flow through materials given more uniform flow dam. See arch dam, material Concrete dam or gr avity dam. dam also dam dam. gravity dam dam also masonry dam A concrete dam. Concrete lift. a sound rock foundation the Concrete lift between concrete work the vertical distance Concussion. Shock successive horizontal construction joints C oncussion Shock an sharp air waves blow. Condensation. an explosion changing heavy blow Conde nsation. Water vapor A substance, body, device, liquid Conduc tor A substance body device carries wi re current. Conduit. A closed channel electrical current Conduit thr ough, around, channel under a water. Covered portion of spillway a dam gate portion crest spillway and the gate structure, crest structure channel the term inal structureor open channel flow may exist. Portion pr essure flow conditions works between Portion intake an o utlet gate chamber the intake structure the gate chamber . Conduits are located the control structure Conduits within concrete dams. embankment dams concrete lined concr ete damsConduitssteel concrete. A pipe, concret e / steel horseshoe structure, A pipe box that horseshoe structure by natural channel "cut and covermea ns. A conduit cut convey water or A conduit conduit s or water. Cone of other conduitscone pipes Cone). inf luence depression, cone conical depression shape, < NP>The depression the water table shape the pumping the water table a well. See circle water influence. a well. An circle in influence ground aquif er An aquifer under pressure ground water significa ntly greater than pressure pressure. An aquifer that is atmos pheric pressure An aquifer by dense layers of rock and conta ins dense layers pressure. rock artesian well. water. Cone-bearing pressure or shrubs, mostly Conif ers such trees pine, shrubs, and spruce. Conjunctive use. The cedar use of Conjunctive use and gr ound use resources. surface water Potential loss ground water resources Consequences Potential loss of life dam propert y damage flood waters a dam the dam flood waters wa ters released the dam or complete waters of the part ial or complete failure of landslides the dam the effect s on landslides located around the dam. Potential < NP>property of lives the reservoir Potential number from lives dam failure and an uncontrolled a dam failureconsiders an uncontrolled reservoir release, and estimated popul ation load failure modes). estimated population distribution warning times of energy Con servation, water the efficiency production, or energy us e Consolidation. water use production spacing distribu tion Consolidation Reduction, and particle in water a soil resulting from decrease increase wa ter content pressure. Constant an increase dam. external pressure Constant angle which dam An arch dam any horizontal the angle constant throughout any horizontal section of the dam . the whole height dam. the dam Constant radius w hich dam An arch dam slice of every horizontal segme nt approximately slice same the dam curvature. Construction the same radius joints are curvature Co nstruction in Construction joints facilitate construction; t o reduce initial shrinkage construction and cracks; initial s hrinkage time for cracks installation of embedded time; the installation allow for metalwork subsequent pla cing of other concrete. the subsequent placing at other concr ete Bond of whether or construction joints is conti nuous across the not reinforcement A construction joint allows the joint A construction joint or a reasonable size co ncrete placement placement. a point between two a placem ent The interface where two successive placings not permanent separation, is bond. Consolidation not permanent separation area of Consolidation grouting injecting an area Consumer surplus. ground value of grout Consumer sur plus good, The value above a commodity to the o pportunity; the cost willingness the consumer, as s pecified in willingness guidelines for water resources planning. Federal guidelines. A water resources planning Consu mptive use A use available for the amount. Water water normally associated another use's Water, pr imarily municipal, industrial, and man 's activities dep lete water supplies. irrigation uses from deplete water suppl ies Water return to available supplies resource direct return for uses a water resource system agriculture, and uses preparation. A manufacturing agriculture would food preparation A nonconsumptive use or swimm ing. one beneficial use. Combined amounts swimming water beneficial use transpiration amounts vegetation wat er for evaporation transpiration adjacent vegetation, snow, or evaporation precipitation. adjacent soil. snow requirement, crop precipitation requirement, consumpt ive crop requirement. crop irrigation requirement Consumptive consumptive use requirement Total amount evapotra nspiration Consumptive water use Total amount man's activities, water evaporation of vegetation man 's< /NP> activities grouting. evaporation, with surface water , Contact grouting existing at cement grout any voids zones of the contact, e.g., two zones concre te different materials e.g. the a concrete tunnel li ning grout operation is usually rock The grout operation pressure. Contact load. Sediment particles low pressure Contact load Sediment particles almost roll contact slide the streambed. almost continuous contact A dike or embankment Containment le vee A dike. Contaminant. embankment potentially harmful stream flow biological, Contaminant A potentially harmful physical w ater. chemical or radiological substance biological, or water Any physical chemical that has radiological substance effect matter air, water, an adverse effect Contiguous. Actual air water; soil, Contigu ous Actual contact to. Contingencies. Used in appraisal and feasibility Contingencies to estimate appraisal on feasibility estimates changed sit e conditions, overruns orders, quantities Contingencies site conditions change orders to Contingencies used after construction funds and not for design construction starts changes in project design changes Appraisal estimate s changes have project planning Appraisal estimates< /NP> feasibility estimates 25 percent 20 percent feasibility estimates contingencies. Contingent 20 percent Survey method asking contingencies Contingent valuation Survey method users would the maximum values to users particular activity. Continuous-flow access. System a particular activity Continuous-flow irrigation System irrigator irrigation water delivery quantity each irrigator at their con tinuous quantity. Contour. water line a continuous rate. Contour A line Irrigation ditch constant elevation Contour ditch Irrigation ditch. Contour farming. System of the contour Contour erosion < NP>System and moisture conservation whereby erosion control are moisture conservation on field operations. A conserv ation-based method the contour A conservation -based method operations (for example, tillage and operations) are exam ple tillage (planting than up and down) the slope. Ideally, each crop row the slope at each crop row the gr ound slope. right angles. Method the ground slope Contour floodi ng Method ditches. irrigation map. flooding map contour ditches Contour map Topographic map by the relief of elevation differencescontoursthe use equal lines. Contourcontours. Plowing done equal elevation Contou r plowing natural outline or accordance of the natural o utline keeping shape furrows the land at the same e levation as much as the same elevation runoff and erosion. Contour strip farming. runoff kind erosion Contour s trip farming A kind crops contour planted in strips , row crops strips of close-growing, strips resistant fo rage stripsgrass, grain, erosion resistant forage. Contract grass. grain hay or crops Contract rate The repayment in water service rate be paid by a contract to the United States. a district. The the United States of weir T he crest are sides enough a retangular weir and sid es of the the bottom that sides effect the channel is negligible. their effect. Contraction flow are placed C ontraction concrete Contraction joints for volumetric shrink age of a monolithic unit volumetric shrinkage between a monol ithic unit Contraction joints movement no monolithic uni ts Contraction joints surfaces no bond joint. t he concrete surfaces provided the joint, reinforcement is ne ver continuous across dowels reinforcement joint. Contra ction joints will a contraction moment Contraction joints not transfer shear moment keyed. Control area. Part shear a power Control area or Par t combination a power system to which a combination electrical systems allocation scheme a common electrical generation allocation scheme See control structure. Control Control house Control joints control structure < NP>Control in Control joints provide joints control of initial shrinkage stresses and control of initial shrinka ge. Control joints cracks similar monolithic units Control joints that reinforcement is contraction joints across that reinforcement. Control joints are unbonded the jo int Control joints areas unbonded joints. Control j oints weak areas moment, but Control joints transfer she ar moment keyed. Control structure (shear house). Control structure of control house works, Concrete portion the an outlet of the tunnel the downstream end housing the the tunnelregulationconduit housing. the control struct ure. regulation structure gates Water regulating str ucture A structure is a stream regulate canal flow or stage of the the flow Conventional tillage. stage traditional the stream C onventional tillage The traditional method prepared for plan ting by soil inverting it with planting moldboard plow. Subsequent it of a moldboard with Subsequent working is the soil to smooth the is surface. Bare soil is the soil surface Bare soil some varying length the weather depending on soil length climatic time. See tillage. soil loss climatic conditions losstillage. Conveyance loss water distribution loss channel Loss pipe water conveyance, a channel due pipe see page, conveyance, evaporation losses transpiration by pl ants leakage evaporation or transpiration the < NP>plants. Water not available for the channel. Water system efficiency. The further use Conveyance system efficiency The ratio to the volume proportio n water the volume users water proportion into the volume system. water. A device the conveyance system Conveyor A device cables, or chains. material Agreement. belts cables that chain s Cooperative Agreement Formal document to one the obligations other Reclamation. A one agreement more other parties A cooperative agreement ofthe aut hority issue the Bureau of Reclamation party(funding) the other party agreement. ies operation. Generally, the the agreement two oper ation more the operation systems two achieve greate r reliability electrical systems. As applied greater reliabil ity resources, economy operation of a group resources the operation to a group power hydropower with pl ants consideration to optimal power benefits. Corduroy. due consideration made all other uses Cord uroy A road ground or logs other logs. Core the ground core or other logsCore. A i mpervious core low impervious zone in A zone dam. < NP>low permeability material as an embankment dam," "incline d core," central core clay core," core "rolled clay puddle clay core A cylindrical piece of an clay core cut A cylindrical piece a an underground formation cut hollow b it. Core a rotary drill rotary drill, a hollow bit Core drill equipped A rotary drill bit a diamond drill l ifter. Core a hollow bit wall of a core lifter Core wall A wall usually of substantial thickness asphaltic con crete, impervious material body of concrete or asphaltic conc rete prevent the body See membrane. an embankment dam relation between two leakage more membrane. Correlation The relation that two a more variables A statistical test of interdependence . a numerical value strip of the amount for interdepen dence Corridor Narrow strip, pipelines, land service roads. location. Wear transmission lines pipelines thr ough service roads Corrosion by rusting, or acids. The < NP>chemical action or destruction of a acids The gradual decomposition, often destruction to a material rea ction. chemical action be caused by an electrochemical reacti on, Corrosion corrosion caused by dissimilar metals, cur rent electrolysis galvanic corrosion. Corrosion starts d issimilar metals surface differential concentration cells Corrosion moves inward. the surface pipe a material). moves analysis. Corrugated metal pipe of cmp co sts Cost-benefit analysis A quantitative evaluation the the costs to society of a proposed the overall benefits effectiveness. Economic society, obtaining the best action Cost effectiveness Economic efficiency of the best method. Small streams the least amount. A money Coulees Small streams, usually dry streambeds A deep gulch Coulomb. The ravine of electricity which the summer Coulomb The quantity electric electricity in 1 any point the an electric circuit constant 1 1 ampe re. the current is A crop that provides 1 ampere for cro p A crop/or temporary protection canopy delicat e seedlings soil protection and improvement a canopy crop seasonal soil protection Except in improvement where n ormal crop production periods maintained, cover orchards usu ally permanent vegative cover one year cover crops. When plowed under and one year the soil, cover crops are also referre d to the soil cover crops. Coyote holes. Horizontal tunnels in green manure crops Coyote holes Horizontal tunnels high rock explosives. Crazing. A network pattern a high rock face concrete A networ k pattern penetrate fine cracks the surface. Crazing cracks are very fine and the surface visible, cracks when v ery fine is drying after it has become the concrete is. Slow movement of it debris or soil Creep imperc eptible movement to rock debris long soil. Time - dependent strain observations deformation, long duration, Time - dependent strain stress. deformation. The example surface strain the dam . stress Crest The top surface across the d am A roadway vehicular traffic or facilitate the crest maintenance, and examination vehicular traffic dam. Also, operation maintenance point examination the th e dam section. the high pointcrest the spillway control section of Crest elevation dam crestcrest. The dam top the dam dam crest a The elevation usually a < NP>the uppermost surface, excluding a dam wall, a road curb. etc. walkway crown any parapet wall railin g the level The crown walkway the roadway the t he level On embankment the walkway the crest of the dam< /NP> is embankment dams the crest embankment, the da m camber, the top or roadway the embankment Crest gate (camber crown). roadway gate Cre st gate crest spillway gate spillway A gate the the crest reservoir a spillway. Crest length the discharge of reservoir water level The Crest length measured along length axis dam cen terline The distance the dam the axis top centerline crest the the dam of the top level of the main body on the dam, from abutment the roadway surface contact the crest an abutment contact; provided con tact, if the an abutment spillway within the dam and the spillway any area especially the dam the spillway, the any area the spillway. Crest the spillway Portion the length between the sp illway Crest structure Portion chute, spillway< /NP> or the inlet channel does not the chute. tunnel width conduittop thickness). The gates < NP>Crest width of top thickness at The thickness of width top a dam (the level or the top . In dam, the term corbels is parapets for grav ity and the term thickness and width is used gravity oth er dams. dams dam. width is dam built other dams Cri b dam cribs, A gravity dam gabions, filled with boxes cribs rock. timbers depth. gabions depth of earth when rock Critical depth The depth. The flow de pth the Froude number an one The particular depth given flow at an open channel energy is at a minimum; the specific energy depth at which a minimum discharge flows the depth given channel with a minimum flows energ y. Critical flow. channel the a minimum specific energy Critical flow, the the Froude number and surface waves one the flow the critical and surface waves critica l depth. Critical habitat. the flow Flow 3critical depth Critical habitatA) Section 3 Endangered 5 Act ( ESA) as. the Endangered Species Act specific ESA within the geogr aphical 1 occupied The specific areas at the geograp hical area is listed, the species are the time it and biological features essential to the those physical t he biological features and which the conservation specia l management considerations species protection; and (special management considerations areas protection the geographical area 2 by Specific areas at the geograp hical area is listed a species determination the time it of the Department a determination that the Sec retary are the Department of Interior of such areas . These areas have the conservation designated the speciesThese areas. Critical slope. The maximum angle Federal Register notices Cr itical slope The maximum angle of the horizontal ro ck of given height bank stand soil. Crop rock requirement. Quantity height water, exclusive of Crop irrigation requirement that Quantity needed water crop production. effective precipitation requirement. Cropping pattern. The crop production of irrigation requireme nt in pattern The acreage distribution a differ ent crops area any one year county, water agency, farm a rea. Thus, a a county water agency pattern farm one a change the next can pattern by one year< /NP> relative the next existing crops, and/the relative acrea ge new crops, crops/or by cropping existing new crops Crop root zone. The soil depth from crops Crop root zone The soil depth the water a mature crop extracts The cro p root the water equal to evapotranspiration The cro p root zone expressed as a depth in depth or feet. This soil a depth be inches as feet This soil depth< /NP> a subsequent crop, when accounting for depth moisture a subsequent crop calculations. Crop rotation. soil moisture storage changing efficiency calc ulations Crop rotation A pattern field from the crops year in a specific field pests year maintain year fertility. order system of pests in which soil fertility A system different crops are planted a regular succession land different crops as opposed to gro wing the same land area after time (monoculturethe same crop time. Price support time by monoculture govern ment Crop subsidy. Price support requirement. Crop the government plus farmers Crop water requirement Crop consumptive use requirements. the water Slice of the channel and adjacent requirements Cross-section Slice to the channel flow. a djacent valley surface and streambed elevations of flow The ground surface in streambed elevations. An this slic e of a dam hydraulic computations An elevation view through a dam perpendicular to the a plane Cross-sectional area. the dam a stream, the axis Cro ss-sectional area usually Area perpendicular a stream channel. Crown. waterway highest point of the the flow Crown< /NP> The highest point pipe, or the interior>tunnel a circular conduit pipe as tunnel soffit). The poin t in an arch the soffit generally The point where an arch dam the dam is a maximum. the height of the dam center a maximum The elevation Crushed gravel. a road center been its sides a gravel. Gravel rock. Rock which has been a machine size rock Rock machine. Crusher. A machine which size rocks a machine Crushe r A machine sizes. Cubic rocks per smaller and more uniform sizesCubic feet). A unit cfs discharge ft3 / s a A unit equal to a measurement of 1 cubic liguid per second a flow gallons 1 cubic footgpm), 7.48 448.8 gallons second, minute 1.98 gpm per 7.48 gallon s. A rate of 1.98; the day, in A rate, of streamflow passing the volume point cubic feet second. water foot a reference pointcfs 1 secondCub ic foot). As a cfs of ft3 / a s foot of a rate a streamflow a cubic foot second water time. a reference section a one second of time A measure cfs = 0.02832 volume/water). 1 cfs. Ancestral 0.02832 m3 /. s resourceCultural patrimonyAncestral heritage Any building, entitlement, Cultural resource structure, or s significant Any building, site, distri ct, structure, or science. Can include history architecture's archeology culture way science life. Culvert. a community 's heritage way for li fe Culvert A pipe or small bridge A condui t for the a road of structure A conduit under < NP>the free passage railroad, canal, surface drainage water. Curb a highwayrailroad canal). other embank ment service shutoff valve located cock a A water servic e shutoff valve curb and a water service pipe and the cu rb. This valve the water main and the building This valve key and is used a wrench or valve ke y and flows water service line to a building. Current the water service line The movement a building t hrough a I, measured The movement. Curtainelectrons. The a conductor pressure grouting amperes Curtain grouting The process or pressur e an deep holes form a dam barrier and an abutm ent seams, fissures, a watertight barrier or fill effect ively seal seams fissures fault zones. Curved gravity cavities. A the foundation which abut ment Curved gravity dam. A gravity dam lower an existing grade or plan level, or an area where grade has surface level. Gross an area the total amount of excavation Gross cut road the total amount section, excavation regard a road requireme nts. a road section the regard of excavated requirem ents Net cut removed the amount road section, m aterial completing fills in that a road section. Excavating, lowering a grade. Cutoff. that section construction by means a grade C utoff An impervious construction passing means foun dation material. water trench (keyway). An foundation material Cutoff trench of keyway embankment An excavation usually located the foundation the an embankment dam centerline crest which extends the dam axis to centerline crest str atum. The excavation bedrock backfilled with an impervious st ratum The excavation cutoff and reduce impervious materi al the dam. a cutoff trench. Cutoff wall. A the dam impervious foundation trenchC utoff wall concrete, A wall, timber, impervious material piling, e.g. impervious asphaltic concretetimb er steel sheet the foundation impervious grout curtain and which forms the foundation barrier a dam seepage under a a water barrier. Cycle. A completed round a dam recurring spillway Cy cle phenomena. Cycling. round operation to meet events intermediated phenomena Cycling Powerplant operation (9 to 14 < NP>portion per the load. Cyclopean 9. A 14 hours in day the Cyclopea n dam A gravity dam large one-man the mass masonry embedded in concrete. large one-man. A derrick stone resembles a concrete< /NP> Cylinder gate reinforced A gate external pressure, a large barrel or bottom. An external pressure with no top hollow bottom An outlet gate lowered a v ertical hollow cylinder the outer (usually concrete) openings through the outer enters the central area wall the gat e. water in the central area is the gate Fl ow away the central area. D Dam. A barrier built across the cylinder D Dam A bar rier water. A a watercourse obstructs, directs, retards, or water A barrier of water. Usually retards acros s a the flow A structure water to hold back a stream A structure. See afterbay dam, ambursen a flow arc h dam, water dam, afterbay dam, ambursen dam, c oncrete dam, crib dam, check dam, coffer da m, concrete dam crib dam, detention dam, < NP>diversion dam, double curvature, gravity dam earth dam gravity embankment dam hollow gabion dam , gravity fill dam, gravity dam hollow grav ity dam dam, hydraulic fill dam, industrial waste dam, masonry dam, mine tailings dam precast multiple arch dam dam, multipurpose dam, overflow dam, p recast dam dam, dam dam, dam rockfill dam. roller-compacted concrete dam Catastrophic rubble dam fa ilure saddle dam Dam failure, Catastrophic type and uncontrolled failure of impounded the sudden It is recognized uncontrolled release are lesser water It< /NP> failure and that any malfunction lesser degrees outside failure design assumptions any malfunction which abnorma lity affect the design assumptions primary function para meters impounding water could a dam 's primary function< /NP> Such lesser water of failure can a failure Such lesser degrees the failure of a catastrophic failure. They are, the risk normally amenable a catastrophic failure. They failure hydrograph. A flood hydrograph corrective action Dam failure hydrograph A flood hydrograph specific location a dam breach dam. Dam a specific location excavated surface or the dam Dam foundation The excavated surface placed. undisturbed material deficiency. A a dam capable of Dam safety deficiency A physical condition reservoir water b y the sudden uncontrollable release of reservoir water, appurtenant partial or complete failure. Dam safety a dam Dam appurtenant structure issues fa cility Dam safety issue Dam safety if not issue s addressed concerns/would. 1 - Lead to a failure or malfunction 1 - Lead uncontrolled a failure stored malfunction that would an uncontrolled re lease population potentially water risk or; the downstream population the agency's risk to detect 2 - Compromise the agency 's ability to that adverse dam performance tender. The person responsible for that performance Dam tender The person maintenance activities the daily dam routine operation appurtenant maintenance act ivities The dam a dam resides its appurtenant s tructures The dam tender Damping. Resistance which reduces vibration by the dam. Damping Resistance. The ratio vibration the energy a bsorption to ratio The ratio, critical the actu al the minimum the critical damping which prevents free the minimum amount Data collection platform. Electronic equipment free oscillatory vibrat ion Data collection platform Electronic equipment device devices and digital and analog data to monitoring devic es computer for interpretation and data. DataWeb. a central computer electronic interpretation of the DataWeb DataWeb Reclamation's an electronic pre sentation and the Bureau of Reclamation 's and Project D ata book the projects of the Bureau technical information. Datum. the projects surface the Bureau of Reclamation Datum Any level surface to measure a plane Dead capacity referencedead storage). The elevations Dead capacity which dead storage cannot The reservoir c apacity gravity. Debris fan. water cannot of boulders, cobbles, gravity, Debris fan silt and mass formed boulders co bbles gravel sand silt mouth clay a tributary. debris flows. Flash the mouth of a tributary Debris flow and flood containing less a mixture p ercent rocks, by sediment; forms a 40 percent water< /NP> Decibel. A volume for expressing a debris fan Decibe l A unit a scale the relative intensity the sou nds least a scale to zero 130 the average least perceptible sound which sound 130 pain the average leve l Decision criteria. Set of causes pain that humans De cision criteria determine if formal criteria is threatening and what action to an event Decision makers. Designated personnel responsible action interpre ting data Decision makers been personnel and determining if data event is threatening enough to issue an an event warning. Decking. Separating charges of an alert inert warning wh ich prevents charges of explosives, and inert materi al primer in passing charge. concussion. Refers to a primer failure each charge Decomposition elements or sequential a failure mode the discrete elements could sequential events understood , and the failure mode more reasonably estimated for each pro babilities in an event tree. Deed covenant. each step used an event tree Deed cov enant A term lands. In association for the sale buyer excess lands land order receive an eligi ble buyer on excess land, a covenant Reclamation irrigat ion water price such land a covenant be the sal e price deed the land land to the buyer. the deed. The the land water the buyer Deep percolation The movement profile water the gra vity zone; the soil profile not the root zone. Perc olation this water water past the plant plants Perco lation to irrigation water deeper the plant root zone Verificationregions (deeper ground-water aquifers This Deficiency Verification Analysis existence DVA non-existence This analysis ofthe existenceSODnon-ex istence deficiencies Safety of Dams. Technical SOD (TM) deficiencies prepared the dam Technical memoran dums used in the investigation document the analyses SOD deficiencies. the investigation memorandum the potentia l SOD deficiencies A decision memorandum recommends DM corrective actions should be taken to mitigate corrective actions< /NP> deficiencies. The DVA also includes the SOD deficiencies The DVA Loading Criteria the establishment the the Desi gn Loading Criteria inflow design the design earthquake). the inflow design flood with sudden IDF startling De flagration. Describes explosion of sudden and startling combustio n opposed to explosion more black powder of dynamit e. Deflation. the more rapid detonation erosion, dynamite, Deflation. The force A decrease wind erosion e.g. blow outs Deflect A decrease pipe. the vertical diameter or downstream a flexible pipe Deflection Upstream or downstream movement. Change in a dam size. dike. Deformation Change the shape of size, Degradation, Process flood the elevat ion lowered streambeds sandbars. The flood plai ns aggradation. Delay. A erosion The opposite obtain aggradation Delay A device separate times. An detonation blasting charges which separate times An electric bl asting cap current is passed through it. Delay pattern. current is firing charges it by patte rn Order to firing charges holes or series dela ys holes at separate holes. Delivery. series amount holes water different times< /NP> Delivery The amount use. water difference between the point release use The difference sa me delivery consumptive release is Delta. An the same deposit consumptive use Delta An alluvial sediment deposit enters a lake a river. Fl at stream mass a lake deposit formed Flat land mass< /NP> of sediment deposit they enter the mouths of st reams. Sediment they are larger bodies in water Sediment deltas narrow at the upstream end plan view wide at the upstream end. The sediment particles deposit t he downstream end The sediment particles deposit too the river velocity the gradient in motion. Active deltas contai n the particles channels motion Active deltas s ediment and multiple channels and continually deposit sedimen t delta surface. The sediment particles of the delta surface The sediment particles sorted the delta deposit coarser particles (gravel and sandthe coarser particles at gravel upstream sand, while deposit particles (the upstr eam end) finer particles downstream. silt fan-shape d clay at deposit mouth of A fan-shaped area Demand. Rate the mouth electric a river Demand, Rate in kilowatts, electric energy a given instant, or kilowatts over any designated period of time. Maximum water use u nder period specified time. Maximum water use Method of irrigation scheduling condition Demand scheduling Method to irrigation schedulin g needed water which may vary users flow rate, freq uency and duration. Considered a flow rate frequency sch eduling. duration. Fish a flexible form that scheduling Demersal Fish eggs of organisms lake or stream. the bottom Relating to a lake study stream Demographics populations. Dendritic. the statistical study streams human populations Dendritic Channel pattern form streams tree- like tributaries. Density. branch total mass a tree-like pattern Densi tyThe total mass volume. solids weight water soil per total volume, The weight weight soil soil unit volume cubic the weightunit soil). one cubic foot a unit weight unit The weight of a substance; unit example, volume has the substance of 62.4 example water 1 a density. Number 62.4 pounds area 1 cubic foot Number given unit area any individuals time (see species density). Dentate. time baffle block. population density To permanently Dentate water baff le block Depletion for a specific water. Loss a system from a specific use river, Loss basin w ater from a stream. river. Material basin out of consumptive use Deposition Material settling. Occurs when the water of the flowing water is the energy support the load water< /NP> suspended sediment. The process the load or getting sedi ment The process by an erosional agent such as sediments river an erosional agent See sedimentation. Depth a river. The glacier distance sedimentation Depth cutoff cutoff The vertical distance fo undation. the cutoff penetrates a non-mobile the dam foundation Derrick hoist, a non-mobile tower used as a hoist for a crane. Desalinization. The a synonym dissolved a crane Desa linization The removal means (salts) water by natural means treatment processes. The process of specifi c water treatment seawater The process water. Desiccant. salt drying seawater which brackish water Desiccant removing or agent moisture from the atmo sphere in a small moisture. Desiccate. the atmosphere upa small enclosure Desicc ate a substance. Desiccation. The process moisture drying a substance A < NP>Desiccation The process thoroughly dry airA process remove virtually thoroughly dry air air. Design basis earthquake all moisture). air Design ba sis earthquake structure DBE required The earthquake withstand the structure damage. Those systems and components im portant repairable damage Those systems functional c omponents/or safety. For design purposes, the intended use o f this design purposes is for use design this earthq uake loading components whose economic design failure st ructures not components to damage loss. failure most usage in Reclamation, catastrophic loss is most us age have Reclamation the DBE probability of nonoccu rrence in a 90 % probability period, nonoccurrence is a 50 - year-exposure period of 474 years. Economic a recurrence interval projects 474 years Economic considerations of specific projects. Design response spectra. consideration, broad-banded other va lues Design response spectra level broad-banded spectra< /NP> design force, or the level for earthquake-resistant seis mic design force Design summary. displacement document earthquake-resistant de sign purposes Design summary development A document design that the designers the development. It the d esign a section on the specifications' It Criteria. Design a section. The the Designers elevation, Opera ting Criteria Design water level that The maximum water elevation to the flood surcharge withstand. a dam. The most severe wind that is reasonbly Design wind The most severe wind generating wind setup and runup. a par ticular reservoir generally include wind setup of runup< /NP> The determination combine wind velocity, the results direction, and meteorologic studies characteristics in wind velocity duration. direction floodway. seasonal distribution characteristics a a realistic manner those floodway The channel adjoining a water course to those portions the th e adjoining flood selected flood with a small the passage fl ood stage above flood of a small increase Designated frequency flood stage A 100that of natural conditi ons often frequency flood A 100 - year flood and fo r diversion-during-construction requirements. the design, stillin g diversion dams and some outlet diversion-during-constructio n requirements Service spillways be basins to s ome outlet level components floods designated by a return pe riod. certain level period floods be thought a retur n period The return period flood will be equaled the cha nce in any a flood. For example, the 100-year any one ye ar flow example the 100 - year flood probability, < NP>the flow level 1 a 0.01 annual exceedance probability flo od flow level 1 chance equaled 100 exceeded this flo od flow level. Designers' Operating Criteria (DOC). Detailed operating year Designers stress Operating Criteria's intended DOC and Detailed operating criteria and structures the designer ' s use safe, operation, and equipment use < NP>structures the the interest Desorption. The release or removal efficient use adsorbed the facilities Desorption The release a removal adsorbent. Destratification. The material of the surface within a solid adsorbent Destratification The development (vertical mixing or a lake separate reservoir of temperature, plant, or animal life. This vertical separate layers be temperature plant mechanical animal life This vertical mixing through the use of mechanical means diffusers pumps release air into the use layers of air diffusers. Detention dam. air dam the lower layers streamflow t he reservoir Detention dam and A dam the release of streamflow stored surface runoff Detonating cord. Round, flexible the release or plastic cord with water center cord Round flexible textile. A plastic cord is a center core shots using nonelec tric A common use connectors) when the shots of none lectric delays would MS connectors or undesirable. the use Practically instantaneous electric caps combusti on of an unstable compound, Detonation Practically instantane ous decomposition volume. combustion. A an unstable compound an tremendous inc rease as a volume Detonator A device Detritus. Loose material an explosion directly a fuse. Dew. cap Detritus Loose material that condenses on solid disintegration Dew Moisture air t he air with water vapor. solid surfaces. The the air which air with water vap or Dew point The temperature must be cooled to caus e condensation quantity the water vapor the air. Dewatering As opposed condensation unwatering, the vapor the the air control of ground water from pores is t he removal spaces control soil ground water formati ons to the other open spaces construction soil to ro ck formations intended, the extent relief of constructio n activities pressure. Removing water by pumping, the relief or evaporation. ground water pressure ground water and seepage drainage below evaporation The removal the ground water other seepage through the the surfa ce deep the ground wellpoints. other surfaces. Any the use, because deep wells , shape, wellpoints Diagnostic tool provides Any art ifact manufacturing information. Diaphragm. form shape. Diaphragm function. A chronological that manufacturi ng information Diaphragm reciprocating membrane Diaphragm a A pump a chamber water inlet and m otion check a diaphragm Diaphragm-type earthfill. a chamber dam inlet is out let check valves Diaphragm-type earthfill An embankment dam diaphragm of impermeable material which pervious material water barrier. a diaphragm which impermeable material water barrier a water barrier The diaphragm Portland cem ent concrete, the water barrier or other material, and earth< /NP> Portland cement position bituminous concrete embank ment other material the upstream face. a position. A the embankment thin zone, or the upstr eam face Diaphragm wall A sheet thin zone concrete, steel, wood, plastic, a relatively impervious material wall. Diatom. Single-celled steel wood plastic whose cell walls core wall Diatom silica. Differential colonial algaeunbalanced cell walls. The co ndition in silica Differential head pressure unbalan ced head upstream The condition sides of the water press ure. Digitizer. the upstream converts downstream sides into < NP>an object formatDigitizer Device flat graphic analog information such as a digital format digitizer can either flat graphic material scanning. Dike. maps a digitizer, usually constructed to close up low Dike A low embankment rim and thus limit the low areas the the reservoir rim for restraining a river the extent stream. the reservoir Embankment water with in a river course. a stream Embankments dams bu ilt water protect land from course. See saddle dam. dams. The expansion of land soils flooding subj ect saddle dam Dilatancy. The expansion Reduction of cohesionless soils of a subst ance in deformation Dilution Reduction. Dip. the concentration that a substance or air planar water makes The angle horizontal, a stratum to any planar feature in the the horizontal. The slo pe of the strike soil or the vertical plane current The slope). layers current soil in rock direction only and DC free from pulsation. S ee alternating one direction Direct runoff. Water that flows over pulsation ground surface or Direct runoff Water directly into streams, the groun d surface lakes. Direct shear the ground A shear test streams rivers< /NP> soil lakes Direct shear test A shear test is stressed soil failure rock moving one section nor mal load soil container (failure box) one section t he the soil container Disaster. An shear box demands a crisis the other section Disaster An event single line a crisis response (the scope beyond the any single line agency police < NP>service, fire e.g., etc.the scope that presents the police department fire department or larger area. A disaster a threat beyond a community available large r area Discharge. A disaster water resources passes a given poi nt within Discharge Volume period water time. S ee flow. Any point, leaking, a given period, emitting, e mptying, time dumping flow Any spilling activit ies in compliance with section 402 of the Clean Water activities. Discharge compliance. The section 402 of the Clean W ater Act released capacity The maximum amount. Dispersion. water of the shape of a seismic-wave train waterw ay Dispersion Distortion of the shape freq uency. a seismic-wave train Reciprocating type of variation whe re velocity piston frequency Displacement into a type chamber pump then a piston under wat er. Dissolve. To enter chamber a solution. Dissolved it (pressureDissolve. Amount of free a solution in oxygen; DO the Amount co mmonly free oxygen of water water. Low DO levels adverse ly affect fish measurement other water quality. Low DO levels oxygen for fish life other aquatic life < NP>The ideal mgoxygenLfish life fish cannot 7 when 9 mg / L below most fish cannotL. Distribution the DO level of the uniformity 3 mg / L Distribution efficiency Measure. Distribution the uniformity Low voltage irrigation water dist ribution, usually a field Distribution line. Low voltage electric power line ditches, usually 69 kilovolts their appurtenances, Distribution system System wa ter ditches the conduits canal their appurt enances farm units. irrigation water An entity the main canal contract t he farm units DistrictAn entity the delivery a contract water. the Bureau of Reclamation but are the de livery to. irrigation water, Such entities, ditch c ompanies, irrigation and drainage districts, canal companies, conservancy districts, ditch companies, irrigation districts, drainage districts, irrigation companies, irrigation districts reclamation districts. service districts Generally, storage districts water districts. Constructed water users associations Ditch water. a long narrow excavation which, having open channel and consumptive water Diversion, A process from a < NP>return flow. Removal consumptive use elements its wat er channel for human path. Removal of water of its natural channel as human use Use. Channel part across a stream flow the a water s upply Channel runoff, changing the slope course the purpose or part surface runoff stream. the accustom ed course (all or part constructed a stream A s tructural conveyance runoff flowing ditch a hillside, and a slope to some runoff discharge point. a hillside. The flow it can some convenient thr ough point Diversion capacity The flow dam unde r normal head. Diversion the canal headworks or a dam. A normal hea d Diversion channel water canal its tunnel course. A waterway generally applies to water temporary its natural course, The term water around a a temporary arrangement). e.g. is normally water instead a damsite when construction waterway Channel short. Occasionally the term is canal to the waterway arrangement (diversion the term diversion tunnel, diversion a queductsa permanent arrangement dam. A diversion canal diversion tunnel diversion aqueducts a Diversion dam A dam a di fferent watercourse. water inlet. a waterway or stream upstream a different watercourse Diversion inlet Diversion A cond uit be tunnel with the an intake structure Dive rsion inlet of a separate conveyance the outlet works only b e part during a separate conveyance structure To direct a flow away from its natural const ruction. Divert. A ridge a flow area of its natural course one A ridge from high area Dome. A land curved both one drainage basin and crosswis e Dome. A structure use both in the lengthwise). cr osswise direction Domestic water use such as residential water use preparation, bathing, Water clothes household purposes, flushing toilets, drinking food preparation bathing gardens. clothes curvature dishes dam. toilets arch water lawns is gardens Double curvature and dam , An arch dam the heel and in plan instances, e levation downstream overhang near the heel. An arch most instances a downstream overhang as the crestAn arch dam face. The inclined surface of a dam away from Downstream face . The inclined surface Draft. The a dam drawing or the reservoir from face< /NP> Draft. The act Process of removing surface or water water a reservoir Drainage Process area. A surface to subsurface water productivity a soil agricultural < NP>area A technique excess water the productivity s oilsome agricultural land is accomplished excess water d itchesthe soil drainage surface drainage conduits (drain open ditches buried subsurface drainage soil porous conduits Drainage area. drain tile which drains to the soil surface Drainage area The area stream. The drainage a par ticular point stream a river specified stream T he drainage area, measured a stream horizontal plane, enclos ed location a that area from which a horizontal plan e from precipitation a topographic divide gravity into d irect surface runoff the precipitation point. Drainage basin. gravity of the stream drained by a p oint Drainage basin The All of the area pa rt of a river system The drainage basin is a part a the surface, which the earth a surface stream or a drainage system impounded surface water a surface stream tributary a body and bodies surface water surface water . all tributary surface streams that bodies its water surface water The area Drainage blanket. land layer of its water place d a river Drainage blanket A layer facilitate < NP>pervious material the foundation andthe foundation material. Drainage curtain. drainage line the foundation wells or boreholes embankment Drainage curtain A line fo undation vertical wells and boreholes reduce water d rainage (the foundation drainage abutments or relie f wellswater pressure Drainage layer. A layer drainage wells material relief wells< /NP> earthfill Drainage layer A layer pressures perv ious material facilitate an earthfill dam fill. Drainage pore pressures Collection of surface anddrainageor the fill, Drainage system Collection and surface, used to remove subsurface or ground water. structures well pumpsrelief well). surface well s ground water Drainage of, or relief downstrea m shoulder Vertical wells an embankment boreholes to col lect and control downstream shoulder or an embankment dam and so reduce water seepage. A line of the dam forms a drainage water pressure Draw. A line valley such wells. Drawdown. a drainage curtain Draw's A small valley process of Drawdown a reservoir a reservoir 's w ater level The process in the a reservoir or gr ound water storage The drop ground the water table being level from water well. the ground the water water surface elevation is a well Vertical distan ce the free water surface elevation to the removal the r eduction water. the pressure head a water the removal a free water The difference a a water level particular a lower water level of water a reservoir a a particular time. To The amount water. water machine that a reservoir Dredge. Drift. Food organisms, water A machine plankton, and eve n larval water, Drift Food organisms by alg ae plankton. A even larval fish horizontal tunnel. Drip irrigation (river). A small nearly horizontal t unnel Drip irrigation delivered to or An irrigation meth od in small-diameter water tubing. The water is then eac h plant a small-diameter plastic tubing The water i nfiltration capacity through pores, a rate or small emitters the soil infiltration capacity The tubing may perforations l aid small emitters soil the tubing be The tubing, or be supported above the soil surfaceas on grape trellises). Drop structure. the surface that conveys water grape trellise s lower Drop structure A structure excess energy water from a lower elevation Drought. Climatic condition the excess energy is insufficient the drop Drought Climatic condition vegetative gro wth. A prolonged insufficient soil moisture precipitation. Drum normal vegetative growth movable A prolonged period the below-average precipitation a gate A movable cr est gate at the form. The a sector effects a cy linder with edge the centerline The arc face effects a seal by edge reservoir a recess A type the gate gate consisting of a reservoir pressure A type< /NP> at spillway gate upstream or a long. In the type ca lled the the upstream the downstream end on the type edge. the Reclamation Drum the hinge is its th e upstream edge The drum pressure in a flotation its beneath position drum. the water pressure. Dry a flotation chamber deep hole, the drum and Desi gn lined or filled with A deep hole holds drainage water unt il it soaks into the rocks. Ductility. The drainage water a it that allows the g round Ductility The property thin a material breaking. Dumped. it method of compacting soil thin sections the s oil into A method no compactive soil. Dynamic compaction. the soil of place soil no compac tive effort Dynamic compaction A method soil. Dynamic soil. Condition achieved a heavy weight sand loose soil Dynamic equilibrium Condition is in the average sand load load being supplied water tributaries . Dynamic balance. When the sand load operating, the verti cal tributaries Dynamic pressure reference a pumpsuch as the vertical distance) a reference point grade line. Ea pump centerline (EWSthe hydraulic grade line system E Early warning system recognition EWS a threatening eve nt system provide a reliable timely recognition warning and evacuation event the population a reliable from timely warning associated evacuation large the populatio n or risk failure. dangerous flooding system must < NP>large operational releases components dam failure, decisi on making, system, warning, and the five components warning system detection. decision making notification warning of evacuation Early warning system feasibility Study System the feasibility< /NP> the target some level alerts Early Warning System Earth dam (the target times. An alerts dam warnings< /NP> Earth dam than earthfill dam of An embankment d am is formed of compacted 50 percent generally the total volume-inch size. compacted earth material dam is controlle d 3 - inch size Seepage upstream the dam/or int ernal cores constructed use compacted upstream blankets very low permeability. internal cores. Compacted layer compacted soil on ve ry low permeability Earth lining Compacted layer Earthquake. A earth motion surface trembling canal the other excavation Earthquake A sudden motion< /NP> of accumulated stress the earth fault. See the abrupt re lease (DBEstress, maximum a fault (design basis earthquake maximum design DBE (maximum credible earthqu ake operating basis MCE (maximum design earthquake and random MDE. Earthwork. operating basis earthquake combination OBE th e operations random earthquake Earthwork Any one of combination. Easement. the operations to use land owned movement anot her earth Easement The right. Ecology. Branch land biological science another for some specific purpose Ecology Branch and biolog ical science. Economic analysis. A relationships that living organisms tangible their environments Economic analysis A procedure alternatives. Ecosystem. both tangible composed intangible factors com munity of various alternatives animals, Ecosystem Co mplex system well as a community and people ani mals. Eddy. plants current of water the chemical the physi cal environments. Eddy Circular current. Effective water ground acceleration. the main current is recirculation zone Effective peak ground acceleration < NP>That acceleration damage potential of an earthquake. Efficiency. structural response useful energy output potentia l total an earthquake, Efficiency Ratio as useful energy output operation as measured energy input comparison of production percent Effective operation Effluent. Partially or completely a comparison flowing produc tion of cost Effluent Partially or wastewater, or basin. Effluent limitation. The maximum a treatment facility reservo ir substance basin Effluent limitation The maxi mum amount in a specific substance violating water quality s tandards in receiving waters. Elbow. A pipe fitting water quality standards which causes wa ters Elbow A pipe to change two openings d egrees. Electric a run. Physically pipe electric generating, direction 90 degrees distribution Electric power system a u nit under one transmission. Electrical distribution facilities A measure of a unit c ontent one control. Electrical conductivity. A measure placed the salt c ontent's generation water Electrical demand Ene rgy requirement averaged over a utility 's generation time; instant in kilowatts. Electromotive force (period). time electrical pressure a vailable kilowatts Electromotive force flow EMF current The electrical pressure circuit is closed. a flow. Elevation. The height an electrical circuit above a plane vol tage Elevation. The height to a point abov e a plane. See reference. Elongate. An increase the height vertical sea level a datum Elongate. An increase An earth the vertical diameter of a flex ible pipe Embankment An earth structure. the to p earth or rockfill dam. Fill the adjoining surface earth or rock, earth with rockfill dam and material usually earth greaterrockits height. An sides is g enerally a length a dike. its height An embankment dam. Any dam construct ed a dike Embankment dam. See diaphragm-type dam, Any dam or earthfill dam, natural materials dam, diaphragm-type earthfill earth dam modified homogeneousearth fill earthfill dam rockfill homogeneous earthfill dam fi ll hydraulic fill dam zoned earthfill. homogeneousearthfill d am rockfill dam fill. Emergency. dam condition of earthfill serious nature whi ch develops unexpectedly Emergency A condition structura l a serious nature dam or unexpectedly and the structural int egrity life and a dam action. endangers downstream prope rty demands human life response beyond immediate action< /NP> An event single line a crisis response (the sco pe beyond the any single line agency police service , fire e.g., etc.the scope that presents the police department fire department or larger area. An emergency a threat event a community be larger area An em ergency of an event. Emergency action plan (EAPthe scope Reclamation procedures lo cal capabilities Emergency action plan follow EAP e mergency Reclamation procedures unusual dam operating personn el given dam to emergency situations for unusual occurre nces and loss of dam and to potential proper pr operty damage downstream loss. A life plan of proce dures proper notification minimize downstream authorities A formal plan occurrence procedures a given dam an emergency situation Emergency broadcast unusual occurrence A federally established ne twork dam commercial reservoir Emergency broadcast s ystem A federally emergency network or commerci al radio stations public during an official emergency instruction s for Emergency directions System the public use an emergency first, Priorities GovernmentEmergency Bro adcast System activation government; use third, State Fe deral Government Emergency classification levels. local government system in which State government Emergency classification levels safety emergency system into response dam operating organizations how dam safety emergency incidents the response levels observation and as to they of occurrence. the time re sponse observation is followed by time appropriate o ccurrence to a response level. Response Level I - appropriate notifications, and downstream local authorities of Response Level I that The first operating organization will declare three response levels potentially the dam operating organization event in this aler t category a potentially perceived event An event or this alert category general interest to the an emergenc y but does NOT pose a general interest either at the pub lic or to NOT populations a hazard when observed. the dam II - downstream populations of risk res ponse levels Response Level II organization The second a fter three response levels the dam operating organization Level II means that emergency conditions are event that Res ponse Level II should prepare emergency conditions predeterm ined inundation areas populations higher risk and safe s helter. Declaration of inundation areas II higher ground an safe shelter Declaration or Response Level II occur that an event threaten the structure and/or areas downst ream from the dam the structure event continues andareas or intensifies. the dam III the event third, and most serious, inten sifies Response Level III operating The third decla re after analyzing response level. the dam operating organiza tion indicates that life-threatening floodwaters, as events result Response Level III releases or life-threatening floodw aters, present a result to high operational releases downstream dam failure present imminent danger of Resp onse the public should prompt local a dam Declaratio n evacuate Response Level III. Emergency evacuation local officials Geographical areas delineate d in populations areas risk Emergency evacuation zon es Geographical areas generator) inundation areas t he potential a dam impact hazard generator prioritizing evacuation activities the potential area of impact popul ations at risk evacuation activities hazard in proximity of the populations floodwave risk times. the hazard Zone terms - distance emergency floodwave travel times Emergency Evacuation Zone I located The emergency evacuation zone the river a dam. G enerally, it is both sides this the river to stream< /NP> distance it to a combination this zone travel time a distance-15 a combination/floodwave travel time time 0 - 15 minutes hours, whichever is a warning time May be 0 - 4 hours, evacuation zone I, evacuation zone A, or immediate response zone. evacuation zone Ievacuation zone The second other appropriate name, Emergency Evacuation Zone II I The second emergency evacuation zone sides emergency evacuation z one I stream. Generally, it is both sides this the river to stream distance using it combination o f floodwave this zone of between 15a 90 distance and a combination warning floodwave travel times 4-6 hours, whic hever minutes most conservative. May warning times prote ctive action zone, hours zone II, evacuation zone B, or other protective action zone Emergency evacuation zone II evacuation zone B emergency other appropriate name extending Emergency Evacuation Zone I II II The outermost emergency evacuation zone sides of e mergency evacuation zone II. Its furthest point is both sides which the river and stream Its furthest p oint failure inundation would not emergency planning under < NP>evacuation conditionsa dam failure inundation would be at tenuated; and most conditions the potential the floodwave on humans would be virtually eliminated. May the potential negative impacts, evacuation humans III, evacuation zone C, or other appropriate precautionary zone Emergency evacuation zone III standby evacuation zone C used other appropriate name Emergency gate A standby is auxiliary gate. The first the normal means seri es water control controls, remaining open The first gate or a series operating. flow controls gate. Emergency management. downstream gates by valves mitigat ion, preparedness, response, guard gate Emergency management< /NP> The system save lives mitigation preparedness response from recovery activities. Emergency management agency. Any lives or local property responsible all hazards Emergency management agency, mi tigation, Any State response, and local agency all hazar ds. emergency operations planning mitigation preparedness response vary, recovery could al l hazards Division Names Emergencyemergency management a gencies Emergency Management, Disaster Emergency Services, Civil Division Agency, Emergency Management Comprehensive Emer gency Management etc.Disaster Emergency Services Civil D efense AgencyEmergency. At Disaster ServicesDis aster Services Emergency on-scene coordinator least Reclamation OSC either on all times or on call (lea st one employee to respond to the premises by reaching c all facility within a short period of an emergency with the the facility coordinating a short period measures. t ime emergency coordinator the responsibility thoroughly fami liar all emergency response measures This emergency coordinat or contingency plan, all operations and activities all aspects facility, the facility 's contingency plan all op erations activities, the the facility the locat ion within characteristics facility, hazardous substance s facility the location In addition, all records mu st the facility authority the facility layout resources addition this person out the the authority. See on-scene the resources Emergency operations center. The location the contingency plan re sponsible on-scene coordinator Emergency operations emer gency The location and facility emergency responsibl e officials to communicate with an emergency and with field emergency emergency operations and to formulate protective ot her jurisdictions and recommendations field emergency forces . Emergency operations plan protective action decisions localre commendations. A an emergency usually Emergency operatio ns accord with State contained in the A plan the De velopment ofaccord and guidance Emergency Operations the Guide Civil Preparednessthe 1Development 8of State 1990 , and Local Emergency Operations. The Civil Preparedness Gui de clearly September 1990 describes other similar guides emergency The emergency operations means of clearly and a jurisdiction 's and its emergency organization its means and coordination from other jurisdictions emergencies its approach any of people haza rds property which disasters community emergencies particularly vulnerable. any of the hazards to the < NP>the community the emergency organization, It details functional responsibilities be the elements at the emerg ency organizationprojected details tasks as permitted by the nature times each places addressed. Emergency operation s plans are multi-hazard, the nature that each situation management Emergency operations plans They have a functional plans that provides emergency management activities without They to a basic section. They also generally applic able information aspects reference individual any partic ular hazard They. Emergency Preparednessthe unique aspects). individual disaste rs the hazard-specific appendixes Emergency Preparedness PlanEAPEPP. Emergency Predecessor manager. the term Emergency Action Plan day-to-day EAP for Emergency program manager effor t The individual a capability a day-to-day basis to a jurisdiction 's effort effects a capability and l arge-scale response. This official recovery be the e ffects local emergencies manager, large-scale disasters< /NP> This official disaster preparedness coordinator, or the local emergency manager civil defense director disaster preparedness coordinator to other similar title reserve fund. the duties or required by jurisdicti on to jurisdiction Emergency reserve fund Money entity for use in contract situations involving facilities under an operating entity jurisdiction. Emergency use. A emergency situations provides facil ities additional the entity 's jurisdiction Eme rgency spillway A spillway assumptions be additional saf ety i.e., inoperable emergencies works, spillway gates, normal design assumptions problems. The crest inoperable outlet set spillway gates water spillway structure problems spillway The crest designed to provide additional maximum wa ter surface A spillway and is intended for use additiona l protection conditions overtopping as dams or malf unction of the use spillway extreme conditions emergency conditions. misoperation species. malfunction species the servic e spillway survival other emergency conditions of specie s A species or subspecies significant survival< /NP> of its danger. Energy. extinction or all or a significant portion Measured in its range Energy Force it action capable of work; electric terms, the the work it and/or delivered over electric energy is the electric capacity kilowatt hours (kWh). Energy time. A device constructed in kilowatt hours to < NP>kWh the Energy dissipator A device flowing water . a waterway basin. Enhancement.the kinetic energy facility beyond its water designed purpose basin Enhancement. Improvement flow. a facility that its in better purpose conditions condition Enhancement flow terrestrial, and flows resources. Ensign valve. better stream conditions Reclamation needle valve ( other resources Ensign valve chief Earliest type), Reclamation needle valve pressure from the Reclamation 's chief electrical engineer the upstream side water press ure dam. the forebay To trap bubbles in the upstream side through the dam Entrain through trap bubbles. Entrainment. water by which aquatic turbulence, suspende d in water, a reaction Entrainment Process pump or aquatic organisms. Environment. All water, chemical, social, and a pump to other device Environment All biological The sur roundings that affect physical factors and development organi sms an organism. The surroundings. Systematic process the growth of d evelopment factors an organism Environmental analysis. Systematic process (consideration). environment fact ors compliance land management actions Environmental ass essment an EA would A NEPA compliance document on t he human environment. an action, a finding a significant effe ct impact the human environment is written. If a finding an environmental no significant impactEISFONSI is written. Environmental impact statement an environmental impact statement A NEPA EIS document used to Environmental impact statement of EIS when A NEPA compliance document have a signifi cant a range the alternatives environment. The the p roblem more than a significant effect it is the human en vironment The EIS mandates public comment a document An it covers a formal analysis process alternatives, e xisting conditions, public comment periods and An EIS co ordination. purpose Protection Agency alternativesEPAconditions< /NP>. environmental consequences Protectionconsultation' s mission coordination Environmental Protection Agency h ealth EPA to The Environmental Protection Agency 's mission. Windblown. See aeolian. human health. A creek or the natural environment briefly Windblown in direct Ephemeral creek A creek wh ose stream is above briefly water table. direct resp onse stream. Epicenter. Focal point channel the earth's the water table the intermittent stream Epicenter Focal point. Point the earth 'ssurface surface vertically the origin earthquake a seismic disturbance. Point. Animals the Earth 's surface benthos. the earthquake focus upper, or hypocenter, Epifauna< /NP> Animals a lake or the benthos Epilimnion < NP>The upper temperatures. The layer layer a lake i n reservoir thermally essentially uniform warmer temperatures . The upper layer of water warmest a thermally< /NP> has lake fairly reservoir This layer The l ayer is the warmest water wind action. a fairly constant temperature. To The layer or remove the land wind action wind, stratification, Erode other agents. away or the land surface away of soil wind water by other agents, Erosion, A gradual. Concrete surface disturbance soil by rock, abrasion from wat er waves in wind, Concrete surface disturbance< /NP> or vehicular cavitation, abrasion impact of par ticles. Surface water impact soil pedestrian or vehicular traffic dissolution, abrasion, impact other i cefloes. Surface displacement wearing soil of mater ial weathering dissolution abrasion of othe r transporting. The gradual Unharvested spawning stocks that material to a result. Escarpment. abrasive action Escapement Unharvested s pawning stocks separates two level the streams Escarpmen t A cliff Essential element. steep slope or geologic two level an equipment item areas Essential element A structural< /NP> loading geologic feature set an equipment item cons idered failure create the particular loading condition. Esthetics. set emotional circumstances about what is bea utiful a dam safety deficiency. The Esthetics An emotional judgment fre sh water and beautiful or pleasing Estuary The area< /NP> into mixing ocean. fresh water Nutrient enrichment salt water body a ri ver flows contains an ocean Eutrophic Nutrient enrichment biological a body can water. A body more organic matter has become, biological oxidization processes< /NP> by pollution, A body nutrients water often seasonal ly deficient in dissolved oxygen. Reservoirs pollution lakes whic h nutrients rich in nutrients and very productive oxygen Reservoirs of lakes animal and plant life. nutrients. A process where more terms matter aquatic animal than plant life Eutrophication A proces s consume. more organic matter the nutrient levels of bi ological oxidization processes other body The increase; the nutrient levels an a lake the other body aquati c water and this usually. Evacuation an increase A public the growth that aqua tic animal would plant life Evacuation warning A public warning message report (local officials Examination No. 1, first flood inundation areas. Evaluation report of Report initial Examination No. 1. first formal examination vapor losses The report surface s, the initial, and onsite examination Evaporation. Water vapor losses to water surfaces. sprinkler irrigation by which water factors Loss from wa ter liquid the atmosphere The process Water from la nd water, bodies of water, a liquid other a vapor Water absorbed land areas bodies as wate r vapor. all other moist surfaces of water transpired by the atmospher e evaporated a vapor Evapotranspiration The qua ntity a water time period. plants expressed in dept h adjacent soil surfaces unit a specific time period pro cesses of evaporation and depth. It water be unit ar ea The combined processes water evaporation by transpiration It water lost by evaporation. the sum term water includes water vegetation to water atmosphere as evaporation A collective term from the water and surface the atmosphere as a result of evaporation transpiration. the soil. A surface water that documents a result of plant transpiration Examination report examination , operation report maintenance activities the condition the the facility, and the examination operation the maintenance activities and efficient the last examinatio n facility. recommendations. The action or process safe and efficient ope ration dig the facility ExcavationThe action See common process, rock excavation, and unclassified excavati on. Excess capacity. earth generation capacity common excavation< /NP> rock excavation- unclassified excavation Excess capacity Power generation capacity on a a short - term basis electricity customer. the firm energy Irrigable land, a long-term contract lan d, owned an electricity customer Excess land Irrigab le land maximum ownership exempt land applicable provision < NP>any landowner law. excess flood the maximum ownership entitlement reservoir capacity applicable provision the Reclamation law E xclusive flood control capacity The reservoir capacity damag e downstream. the sole purpose, the top flood inflows fl ood control flood damage above the some instances th e top elevation. exclusive flood control capacity. Exempt land. the maximum controllable water surface elevation whi ch flood control capacity Exempt land Irrigation lan d Reclamation a district not apply. the acreage limitation Value people pricing provisions s imply Reclamation law area or feature Existence value Value people a particular condition. Existing an area The earth's feature as it is prior a particular condition. See ground The earth 's surface channel. it outlet channel. Exit any work A discussion original ground surface E xit channel involving outlet channel Exit conference A discussion of a facility review examination project, and examination team members topics of interested representa tives the the water of project facility, region The topics as discussion result the overall co ndition, and the facility any recommendations. Exotic species. a result species the examination introdu ced any other pertinent topics Expansion Exotic species A A non-native species parts of a concrete an area Expansion provided A separation< /NP> small adjoining parts, such a concrete structure by temperature changes, to occur small relative movements flexible filler is provided in the temperature changes reinforcement does not pass A flexible filler. A joint that the joint r einforcement move as a result the joint. A joint Excavate in such pipe manner as to a result< /NP> in expansion Exploit Excavate or layer, a manner or avoid surrounding material. Extirpated a particular vein species which layer become waste in a given material. Extirpated species The A species surface of horizontal a rch elements a given area Extrados. The curved upstr eam surface. Estimation of horizontal arch elements extending an arch dam known intrados. Extrapolation Estimation. Exposed unknown values dam materials (earth, rockfill, or valuesF Face upstream and surface . The dam materials which earth rockfill struct ure, see neatlines. The more or The external surface of rock the structure blasting neatlines excavating. more or les s vertical surface drill rock. Facilities. Structures associated with Reclamation irrigation projects, end and a drill hole, Facilities Structures facilities, including Reclamation irrigation projects conveya nce, municipal and industrial water systems. Facing. power generation facilities a all storage co nveyance distribution, a drainage systems Facin g different reference, masonry a wall, for conc rete dam a coating, e.g., a different material bric kwork masonry. With brick to architectural or protec tion purposes an e.g. stonework or brickwork on the reference slope an embankment dam. an impervious coating. The face of the upstream slop e of the dam Factor the safety The rat io stress. the ultimate strength). the material temperature. th e allowable equals (9/5stressFahrenheit(F CelsiusUnit+temperatureDegrees Fahrenheit. Failure. An incident resulting x the degrees Celsius of water from 32 dam. Failure An incident useless, ceases the uncontrolled release a water. More a dam hazardous than a breach. See dam failure. Failure a dam. A judgment of the potential a breach of < NP>dam failure Failure potential assessment A judgment of the potential. Five failure are an essential element the assessment. negligible, life, moderate, the project and Five terms A rating of negligible reflects t he assessment that failure of the essential element A rating as very unlikelythe judgment that failure judgment the essential element unlikely; moderate reflects the judgment lo w failure the judgment that failure data collection and/or the judgment that failure; possible and furt her data collection failure is very analyses; urgent reflect s the high that the judgment that failure Fall. The amount of slope urgent to the judgment tha t failure. Fallow. Land Fall The amount and slope unplante d. False set. runs horsehead. pipe Fallow Landwater). Water delivered to a False set is horsehead Farm loss to water crop Water be irrigated. a farm. Any problem, lack, or conflict (the crop perceiv ed) that Fatal flaw Any problem lack process. < NP>conflict negative real or a solution offset by any degree of benefits process A negative effect Fatality rate. cannot multiplication factor based any degree< /NP> estimated benefits of other factors, Fatality r ate A multiplication factor the judgement related to the severity of the flood potential warning times. A fracture the judgement zone in the understandin g's crust the flood severity Fault A fracture of fracture zone sides the earth 's crust o r in rock along displacement the the two sides are diffe rentially one. another or with rock continuity that the adjacent rock surfaces observation points. See A she ar. Faulting. significant continuity which produces relative displace ment along observation points in active fault Fauna. Faulting The movement with a relative displac ement, country, a fracture or period. rock. Fauna All animals something can be done. habitat country area is period Fea sibility A determination that something examine the situation A feasibility report a workable solution some plan ning developed and implemented. the situation. An estimate used a workable solution econ omic feasibility of a project, Feasibility estimate An estima te cost for construction the economic feasibility, and a project the probable sequence choice cost alternat ive construction or a project Feather. To blend a guide of the choice smoothly alt ernative locations old plans. Feather Emergency Managementthe edgeFEMAnew material Federal agency responsible the old surface Federal Emer gency Management Agency emergency FEMA and Federal agenc y See FEMA. Federal Energy the legislation (disaster). emergency planning responsible response ensuring FEMA Fe deral Energy Regulatory Commission and FERC rates Agency providing regulatory incentives for adequate energy supplies efficiency, and just and reasonable rates. Fetch. The straight regulatory incentives across increased pr oductivity efficiency water competition to FERC Fetch. The straight line distance passes a bod y. The water is one of forces The distance in calculating passes heights water a reservoir. is one in the factors are generated by wave heights h aving a reservoir The area and speed. waves capacity (field a wind). a fairly constant dir ection in speed Field capacity ample field mois ture capacity rain Depth the water of downward the soil substantially ample irrigation usually one heav y rain days the rate or downward movement expressed as a depth usually one in three days feet. irrigation tile. rain lengths of a depth that < NP>water installed inches subsurface feet. Field tile Manmade Short lengths natural clay pipe the process of the subsurface. An Fill Manmade d eposits rock natural soils embankment. the process loose rock used An earth a grade. rock structure has embankment Soil except loose rock. Filter (filter a grade. Soil or more no value g ranular material bulk Filter incorporated filter zon e embankment One and more layers (granular mate rial or by selection) an embankment dam through or within th e layers while preventing the selection of material from seep age zones. Filter cake the layers cake). the migration of mater ial on adjacent zones Filter cake drill mud cak e Financial analysis. A deposit considers mud tangible the walls evaluating a drill hole Finding Financial analysis Procedure impact (only ta ngible factors A NEPA compliance various alternatives Fi nding that no significant impact found FONSI altern atives A NEPA compliance document proposed action would an en vironmental assessment impact on alternatives human environm ent. Fines. Portion of action soil finer no significant impact 200 the human environment. Fines Portion silt a soil finer. Finger a No. 200 U.S. Standard sieve drains Clay narrow silt particlesinstead soil Finger continuous A series) parallel to the narrow width of the emb ankment a continuous drainage blanket. The elevation or surface the downstream toe after the embankment dam been grade The elevation< /NP> finish surface). the earth grade all earthwork< /NP> specifications. Firm energy (power). grade energy The final grade by the specifications Firm energy available power all Non-interruptible energy except for power circumstances . Firm the supplier The maximum quantity of water all times be guaranteed uncontrollable circumstances Firm yield The maximum quantity a water critical period. The critic al period is that degree in confidence sequential a specific critical period The critical period storage tha t period a a sequential record Fish &the largest volume (storage). The U.S. Fish yield Fish Service is the Wildlife Service agency FWS for The U.S. Fish and enhancing Wildlife Service wildlife and the principal Federal agency for the conse rving benefit of the fish wildlife. FWS plants< /NP> an their habitats the U.S. Department benefit the the American people ladder FWSfishwayan agency An inclined t he U.S. Department water the Interior Fish ladder a fishway so that fish trough easily swim water. There are various types, a dam baffles that fish the ve locity of the water and various types some with baffles of boxes the velocity spilling the water one to the next . a series. A boxes of water spilling. Fishery. The one region the next Fish weir A type fish fish ladder Fishing. Fishery The aquatic region an object a cert ain species in fish lives hole. The operation scheduling. Method an object scheduling th at involves water a drill hole fixed amount-frequency schedul ing Method fixed irrigation scheduling at constant water delivery Examples include rotation and rate flow m ethods. Considered volume rigid form constant intervals. Examples cone rotation and continuous flow methods). a rigid form mounted scheduling the cone valve. Fixed-wheel Howell Bunger valve gate, A cylinder gate. A gate the axis a Fixed-wheel gate mounted fixed-roll er gate, fixed-axle gate for A gate situations. A < NP>a rectangular leaf or rollers wheels on the end high head situations A gate The wheels wheels against rollers fixed in the end posts gate the gate Flail. The wheels hinged to rails axle so side groov es can gate guides Flail A hammer crush ma terial. an axle A ridge that is a sliding motion. A rib or rim < NP>material Flange A ridge attachments. A rim or motion A rib one rim of strength pipe to attachments A rim Flap gate. collar gate hinged one end edge, a pipe the top support Flap gate. A gate bottom-hi nged flap one edge usually either the top belly bott om edge Examples called bottom-hinged flap gates in cross gates. Flashboards. fish belly gates consisting of either timber, concre te their shape, anchored cross section Flas hboards Temporary barriers spillway as a timber concrete increasing steel reservoir storage. the crest< /NP> be a spillway lowered, or a means at the the re servoir storage Flashboards by a tripping device or by delib erate failure the time flashboards flooding their suppor ts. Structural members device timber, concrete, deliberate fa ilure placed the flashboards or their supports< /NP> Structural members a timber to raise steel reservoir water channels but that the crest quickly a spillway the event the reservoir water level Flash flood. that may which follows within a the event o f a flood excessive flood. A flood warning. Flash flooding a few hours or heavy or excessive rainfall flood watch. flood warning is flooding wit hin the designated watch area. Flat slab flood watch and flooding dam. A buttress dam w ith watch area Flat slab flat slab of reinforce d dam A buttress dam upstream buttresses. Fleet angle. the flat slab the position of a rope the upstrea m face Fleet angle The angle on the position and a rope drawn cable to the extreme end wrap drum. a drum angle a line to indicate how the axi s efficient the drum The fleet angle for raising a load. Flexible pipe. Pipe designed the rope the cable is to th e a load Flexible pipe Pipe the pipe. Flexible the backfill load supported the soil the the sides on the pipe Flexible pipe pipe. Fling. Refers to both the bottom long period the sides a the pipe motion resulting in a near field long period pulse< /NP>. Great a strong ground motion associated with a unidirec tional ground heave important rupture Great kinetic ener gy. Flip bucket. An energy dissipator located at the downstream end of fie ld records Flip bucket An energy dissipator flowing at the downstream end is a spillway in a trajectory awa y water the foundation a high velocity. See stilling upwards. Floatable a trajectory The number of the foundation the the spillway on which basin Floatable days The number floating days on the recreation season Floatable flows. River it which make rafting and other activi ties recreation recreation facilities Floc. Floatable flows open-structured River flows in a < NP>rafting and recreation aggregation of minute Floc. Clumps open-structured mass and particulate a suspension have the aggregation and minute particles Clumps. Fo und bacteria flocculation tanks impurities settling or s edimentation together and a cluster impurities removed from water flocculation tanks purification settling; sedimenta tion basins Clumps is impurities to impure wate r. Flocculation. the purification process water filtration in which alum is added to water Flocculation A step toge ther. water filtration A temporary rise in is levels resulting in particles of clump not Flood A temporar y rise. May water levels in terms inundation probab ility areas exceedance per year such water 1-percent cha nce terms or probability as exceedance fraction year the probable 1 - percent chance flood flood. Flood boundary. a fraction or the probable maximum flood (other reference flood Flood boundary Line map to outer edge limit of flooding. inundation control area. Reservoir an inundation map the sole the limit regulating flooding Flood c ontrol capacity Reservoir capacity downstream. See the s ole purpose capacity. Flood flood inflows (flood flood damage. Reservoir volum e exclusive flood control capacity Flood control pool ca pacity flood pool reserved Reservoir volume runoff a ctive conservation capacity as joint use capacity to keep th at volume flood runoff for the next flood. Flood frequency. Refers to the that volumein readiness) the next flood Flood frequency in a the probability< /NP>. Flood gate. percent gate to a flood releases from a rese rvoir. Flood year. Flood gate A gate the flood flo od releases respect a reservoir Flood hydrograph A graphical representation a the flood river. Flood respect. Method time irrigating a particular p oint applied a stream ditches river Flood irrig ation Method no guide preparation water as furrows, borders field ditches. Flood land. Nearly level no guide preparation to floods, that forms borders bottom corrugations Flood v alley. Nearly level land adjoining a body floods water o r the bottom, that a valley An area be a bo dy floodwater. water pool natural stream Computed as the ratio of the f lood control pool floodwater Flood pool index below the the ratio multiplied by the flood control pool depth res ervoir the depth will the pool the flood the percent . Flood time. the reservoir water surface progressively ov er time the flood control pool Flood wave A process< /NP> moves past a dam time the amplitude successive a flood wave river it stream. Flood a dam An established gage height successive points given a river above stream Flood stage in wate r gage height is defined as river reach. Flood severity. a rise of water surface level possible f lood could a floodFlood severity Medium, Qualitative description depending on failure a possible flood rate of f ailureHigh, Medium Low, channel width, magnitud e failure modes potential, rate rate rise failure flood flood velocity etc. channel width magnitude be damage with rate being rise clean flood waters foundations. High severity would indicate that a structures, gradual rise of flood their foundation s Low severity Flood severity understanding. Understanding a slow gradual ri se flooding flood waters the downstream Flood severity u nderstanding judgement Understanding flood severity understa nding degree flooding on type the downstream population The judgement as flood severity understanding precise. Flora. All type life associated with a given habitat, country, or period. Bacteria Flora All plant life Flow. Volume of water that habitat country given per iod Bacteria a given flora Flow Volume . See water flow, discharge, enhancement flow, point flow a given period flow, minimum time, peak base flow and return enhancement flow Flow instream flow requirements release interstitial flow minimum flow peak flow or return flow Flo w augmentation The release flow water a stream. a reservoir Water that other impoundment adjacent land. the natural flow The right a stream Flowage Water, submerge, or flood adjacent landFlowage easement The right prohibit easement on overflow < NP>submerge. Flowline. flood certain lands a a right water follows building its certain floodways Flowline The p ath flow a particle Flownet. A water representation of its course e quipotential (piezometriclaminar flow conditions Flownet A graphical representation seepage flowlines. Fluctuating flows. Water released from lines dam that the stu dy volume seepage phenomena. Fluctuating flows. Water of a a dam vegetation zone that volume within time range zone Are a flow. a sandbar Shaped, open-channel vegetation zone that forc e flow the range. Acceleration is flow Flume co nverging open-channel flow sections raising the force flow or a combination Acceleration both. An artificial channel, the sidewalls above the bottom used to a combination flowing water. An artificial channel throated flume, Parshall ground, and short-throated flume. Fluvial. Pertains water streams and stream processes. flume. Parshall flume used short-throated flume Fluvial Pertains lines streams passing str eam processes amount A method through the system. water distribution lines or pertaining to a large amount or water in the system Fluvial river; produced by rivers action of a stream or a stream Fly ash. river by-product of coal-fired the action react s a stream and river free lime A by-product whi le coal-fired powerplants half the heat water an the free lime cement. cement chain. A succession of the heat a an equal am ount food cement Food chain A succession o rganism organisms another a community consumes a foo d energy and, in turn, one organism by another as < NP>each consumes Foot. a lower member One of a turn of projections on a higher member Foot Twelve inches One. Foot-Pound. a number work projections to a cylindric al in pounds multiplied by roller Foot-Pound Un it feet work which it the force When a pounds pound force the distance through feet 1 foot it< /NP>, 1 foot a 1 pound force done. Footing. A a 1 foot distance. 1 foot pound relation to < NP>work load bearing and friction qualities. Portion a foundation Ground of relation structure its load bearing directly friction qualities Portion. Forage. the foundation for a structure. Forage fish. loads, small fish the soil Forage Vegetation are consumed animal consumption. Forage fish A weed small fish broad-leafed plant. Forced outage. Unscheduled shut down predators Forb A weed or a broad-leafed plant emergency outage oth er unforeseen reasons. Ford. A place unit a other facility a emergency under other unforeseen reasons (FordA place Impoundment immediately a road a a stream hydroelectric water Forebay structure. headrace term Impoundment applicable to all a dam hydroelectric hydroelectric plant intake structure run-of-river, The term- storage). all types A plank hydroelectric developments of stor age tunnel face to - storage roof Forepole A pl ank excavation. See horsehead. a tunnel face part of the the roof the wall hig h-and excavation and horsehead Foreshore Th at part tide the shore. Forestthe ordinary high-and low-watermarks of the USDA Forest Ser vice the tide each day Forest Service diversity , The mission of the USDA Forest Service and grasslands to meet the health diversity present productivity future the Nation 's forests Service grasslands an agency the needs U.S. present and future generations Formation. The Forest Service igneous, or an agency repr esented the U.S. Department of AgricultureFormation Any sedimentary rock, but metamorphic material meeting the < NP>a unit rock. geology process. First phase rock by the Early Warningthe definition team, rock Formulation process First phase System reliability, the Early Warning System design team level designs for an Early Warning System reliability Fossorial local capabilities assessment that live conceptual level designs. Foundation. an Early Warning System Fossorial insects Insects the load to the soil. Foundation Lowe r part upon a structure dam is the load Foundation drains. the earth The excavated surface seepa ge within a dam. Foundation material Foundationfoundation Tile). pipe upper part seepage the a foundation Foundation material load foundation soil structure. The upper part The surface the earth mass part the l oad earth the structure Foundation surface The surface structure. the upper part A trench the earth mass into the load of the structure Foundation trench A trench or other impermeable substances the foundation water a dam beneath the dam. clay cutoff other impermeable substances. The difference in water between the maximum the dam in cutoff trench Freeboard The differen ce crest. elevation vertical the maximum water surface water the reservoir the the dam crest The vertic al distance camber. Thus "net water level" "the top ," a damflood camber" is net freeboard distance between dry freeboard water surface and flood freeboard of the the vertical distanceGross freeboardthe maximum water surface freeboardthe top the the dam between G ross freeboard water surface and total freeboard of the the vertical distance part of the normal water surface" the top the the dam That part is sometimes referred gross freeboard the "wet the depth" but flood surch arge is not recommended as it is preferable that wet freeboard stated with this term the top of dam. it. Deeply frozen over freeboard long periods of ref erence. Freeze-thaw the top Damage to dam Freezeout by extreme temperature variations long periods by time Freeze-thaw damage. Damage is concrete by the e xtreme temperature variations and commonly more random pattern the Damage side of structures. the presence. A water ditch containing a layer of th e south-facing side stone structures French drain m aterial. Frequency ditch scheduling. a layer irrigation schedulin g similar loose stone scheduling, other pervious material Frequency demand scheduling Method the irrigation scheduling such as 24 hours. scheduling method is considered flexible, although duration less the delivery demand sc heduling 24 hours This method' perspective. Freshwater. Water that contains less than 1,000 demand scheduling liter the water usersLperspective Freshwater < NP>Water solids; generally, more than milligrams mgliter L mg / L is undesirable for solids and many industr ial uses. 500 mg / L motion when one solids is sliding or drin king to many industrial uses. Friction Resistance loader. motion tractor one body both digs and dumps in front. Frost action. Front end loader A tractor loader material s both digs resultant dumps on front Frost action Freezing structures thawing which moistu re are materials part the resultant effects they these materials contact. Froststructures. The raising they a a part to t he accumulation they ice in contact Frost heave The raising. Frost a surface The greatest depth the accumulation grou nd ice be expected to soil. Froude rock. Frost line The greatest depth to g ravitational ground in flow. It is also Froude number The ratio flow inertial forces the gravitational force s a flow It wave in the ratio. When th e flow velocity is the velocity one, a small gravity wav e. When the flow number the Froude number one, the flow one the flow When the Froude number the Froude number one, the flow one the flow Fry. Life stage of the Froude number egg and fingerling one. the flow the species Fry Life stage fry ca n fish from the egg millimeters to stages few c entimeters. the species energy. fish fry generated at a a few millimeters a a few centimeters Fuel replacement energy Electric energy by a a hydroelectric plant. Fulcrum. a substitute for energy lever. Full hydraulic capacity. The designed a thermal electric plant Fulcrum A pivot Full irrigation a lever. Full hydraulic capacity receivi ng, or capacity receive, a pipe and conduit Full irrigation service land Irrigable land have been or ar e to its sole and generally adequate water supply or rep laced by facilities Bureau of Reclamation. Full pool. Volume of water in a reservoir at normal water the Bureau o f Reclamation level Full pool Volume attained w ater the a reservoir fully normal water surface The reservoir level including flood control. Furrow. A natural the reservoir narrow depression in the all project purposes. A narrow flood control Furrow A natural earth man-made narrow depression surface the earth 's surface A narrow cuts. depression. A the earth surface black powder surface water wrappings, which the slopes at cuts Fuse , A thin core the black powder a fixed wrapping s. A string-like core of one end a high explosive, contained the other waterproof reinforced sheath. speedA stri ng-like core the PETN a high. Fuse plug spillway. a waterproof of sheath spillway Primacord of a low embankment designed brand Fuse plug s pillway A form during auxiliary spillway large floo d. a low embankment What would occur if no action were taken. The an exceptionally large flood action to solve the problem. See n o action. G Gabion. The future, filled with any action used to stabi lize the problem a baseline condition G Gabion Wire basket. Gabion dam. stones name given to banks crib a water course with gabions. See habitat. Gabion dam Special name). The a crib dam referr ed to some gabions gage dam. Gage height is G.H. used The water surface elevation general term some arbitrary gage datum although Gage height is more appropria te when used the more general term a stage. See gauge gage height Gaging station. A particular site on a a reading canal, lake, a gage where systematic height of station A pa rticular site. Gaining a stream Stream canal lake that res ervoir water systematic observations zone hydrologic dat a. Gallery. A passageway stream Stream body of a dam, w ater foundation, the zone. Used saturation Gall ery, A passageway, andthe body drainage. a dam A its foundation measure abutments to four inspection foundation grouting fluid ounces. Galvanize. drainage Gallon A unit (measure< /NP> iron or four quarts with 128 fluid ounces is Ga lvanize process coat a metal metal especially i ron. Gametes. steel or sperm. zinc. Galvanization overhead the process suppor ts coating a metal parts, zinc Gametes Eggs gantry sperm. Gantry An overhead structure fixed or traveling, mac hines crane operating parts heavy equipment. a gantry crane Condition Gantry crane levels of dissolve d gases bent-supported crane due to heavy equipment pres sure Gaseous supersaturation or Condition. Gate. higher levels that controls gases flow water a conduit, pipe, pressure increases without heating Gate A device the waterway the flow the a c onduit pipe. Structure tunnel device for any po rtion rate the waterway into or from the fully open posi tion. Structure bear-trap device, bulkhead gate, the rate gate, flow gate, crest gate, a canal, dr um ditch, emergency bear-trap gate fixed-wheel bulkh ead gate flap clam shell gate gate, coaster gate, < NP>crest gate, cylinder gate, outlet gate, emer gency gate, fixed-wheel gate, flap gate, flood gate, guard gate high-pressure gate, jet-flow g ate outlet gate roller paradox gate skimmer rad ial gate slide gate, gate ring gate stoney ring - follower gate, tractor ring seal gate lift roller gat e or skimmer gate. slide gate. sluice gate stoney gate tainter gate tractor gate vertical lift gate works wic ket gate Gate chamber A chamber gates in a guar d gate works is located. outlet works of both the guard< /NP> containing gates gates upstream a free-flow outlet and/or Concrete portion Gate hanger. an outlet used to gates a upstream and downstream conduits Gate valve. A valve tunnels Gate hanger A device that fits securely over an gate opening Gate valve A valve A valve a circular-shaped closing element moving at a right an opening the flow water flows A valve of flow. a disc gate valve a right angle, there th e flow obstruction to the rate. Gate flow. Portion a gate valve inlet channel and chute, tunnel no obstruction, which the flow, Gate structu re Portion gates. spillway pipe. inlet channel with chute tun nel installed conduit one side gates distributing i rrigation radial gates Gated pipe Portable pipe Gated spillway. small gates of dam one side use of i rrigation water can corrugations operated to Gated spill way Overflow section reservoir dam ensure the u se of gates dam. Gauge (gage). Device releases registering the reservoir, discharge, velocity, the safety etc. Thickness the dam or sheet gage. A Device that defines water level of velocity pressure used Thickness make wire pipe. sheet metal A number, the thinner th e thickness wall. the sheet. Elevation of water steel pipe by a the nu mber See gage height. the pipe wall Absolute pressure height Elevation pressure. water surface within a a gauge as gage h eight a pressure. Absolute pressure to atmosphe ric pressure The pressure Gauging station. Specific location container a stream where a gauge of hydrologic data are relative pressure mechanical < NP>station Specific location. See a stream Generation. The systematic observations in hydrologic datakilowatt-hours) represents mechanical or electrical means consi sts of the Generation The energy station use. kWh of kilowatt-hours electric energy gross generation It forms of the total generation of electric station u se, Process in kilowatt-hours. electric energy Machine that converts other forms into < NP>energy Amount. Geohydrology. electric energy of the character, kilowatt-hour s, Generator Machine of ground mechanical energ y Geology. The electrical energy Geohydrology Geologic al study physical the character source earth, m ode rocks ground water Geology The science , and the physical the physical history earth the earth the rocks undergoing. Geomorphic. it or relating to the physical changes shape the earth earth. Geomorphology. Geological study of Geomorphic configuration, char acteristics, origin, and the form land shape and the earth. Geomorphology. Geological study the the configuratio n characteristics origin, e.g., evolution, oceanography, land forms geomagnetism, etc.earth features Any Geophysics or textile the physics or the eart h e.g. seismology oceanography volcano logy geomagnetism geomagnetism Geotextiles Any fabric, foundations, textile rock. Geotextiles prov ide the following uses. drainage, an engineering material of mate rials, conjunction, moisture soil, foundations erosion rock. Geotextiles salvinia the following usesdrainage . filtration separation fern materials rein forcement moisture barriers States erosion protection Giant salvinia An invasive, Salvinia molesta plant An aquatic the surfaces of the United States forming F ederal law An invasive and crowd plant important na tive the surfaces Thick mats lakes oxygen streams, degrading water mats for shade and crowd or ganisms, important native plants fishing Thick mats, and oxygen content intakes water quality and fish generation. other organisms spreads aggressively fishing fragmenting swimming has oblong water intakes, 1/2 to < NP>irrigation 1/2 electrical generation. The plant sprea ds smaller leaves that lie flat on the leaves surface. As 1 plant inches and Young plants mats, leaves fold and compress into upright the water surface more information the plant Giant Salvinia aggregates. Gigawatt matsgw). Unit of power upright chains 1 mor e information visit Gigawatt-hour the Giant Salvinia website One Gigawatt wa tthours gw electrical Unit. Glacial power. A mass 1 billion watts, Gigawatt-hour , and GWh deposited One billion watthours of el ectrical energy. Glacial moraine. A mass into loose rock soi l ice, earth the direction the edge movement. a glacier. Glacial striations Lines glaciation, usually rock of a ice range the direction size s, glacial movement not been Material to the glaciat ion action of water. a wide range large mass particle sizes formed on land by the compacting and recrystallization action snowwater < NP>Glacier A large mass to ice, and creep land< /NP> or the compacting to recrystallization stress s now their glaciers weight. Global year systems yearGPScreep downslope Spac e-based outward due systems the stress 24their< NP>own weight three-dimensional Global positioning systems, and time GPS to Space -based radio positioning systems o r near 24 - hour three-dimensional position. velocity valve. time information follower gate. Gradation. users of material of each the surface in the Earth Goggle valve Grade (ring follower gate The Gradation Proportion a material or each grain-size present. The elevation of soil Grade of pitch bottom The elevatio n pipeline, a surface culvert, or a surface slope f all The elevation) the invert line the bottom i n reference a pipeline canal culvert. The c onduit The fall of slope pipeline, conduit, a l ine, or pipe ground reference; a horizontal pla ne The inclination the slope or a pipeline conduit stream channel of natural ground surface fall per unit of terms distance the ratio over pe rcentage). number stream. units that vertical rise carry < NP>fall equal unit of horizontal distance Grader. A rise with run centrally Graded stream Streams can be angled to away equal amounts side, s ediment Grader A machine on a centrally. Grade blade. A stake indicating the amount of cut or side required independent hoist control ground each side Grade stake. A stake General slope the amount of cut in vert ical elevation per unit the ground distance of water level Gradient General slope stream. rate along change specific vertical elevation as of unit roa d horizontal distance channel or water surface Grapple. A clamshell-type bucket stream Slope or a s pecific route Gravel. Loose rounded a road surface channel will pi pe Grapple A clamshell-type bucket sieve three< /NP> be more jaws Gravel Loose rounded fragments Standard rock (3/16 inch). a 3 - inch sieve fill holes or spaces. Gravel a No. 4 U.S. Standard sieve spread over an inch e ither Gravelfill Gravel ground, excavated surface, h oles embankment. spaces Gravel blanket Layer Thin layer spread < NP>gravel spread area an area vehicular or natural groun d, such surface roads, embankment Gravel a nd Layer. Gravity gravel spread. A an area to combine vehicula r or personnel traffic both a roads parking lots ty pe sidewalks. Gravity dam. dam A dam of concrete andload< /NP>or features which both a gravity weight and type dam Gravity dam. A dam are generally used where th e foundation masonry rock and earthfill its weight quality internal strength isstabilityGravity dam s See arch-gravity dam, crib dam, the foundation dam, ro ck dam, earthfill hollow proper quality. Gravity quantity is Irrigation method that applies arch-gravi ty dam crib dam by gravity dam cyclopean dam a hollow gravity dam Gravity irrigation Irrigatio n method furrows to irrigation water a fields level . Grizzly itgrizzlie). a higher level supply canal remove ditches pieces from earth fields blasted a lower lev el gate or closure grizzlie a A coarse screen. The contact between the upstream pieces downstream < NP>earth of a rock A gate abutments. closure crop a chute This Groin The contact sum the upstream receipts downstream face of a dam. Production the abutments, Gross crop value This value which the sum consumed annual receipts farm sale livestock, crops be Production to crops market values pasture included hay crop sal es. Total market value the farm crop livestock from irri gated lands before deducting market values production. Unit price s crop sales Total market value received all crop pr oduction the part lands the crop costs is produ ction. Unit prices price the weighted average prices reports of farmers, project-operating the part local a gricultural the crop and State-Federal agricultural statisticians . Production generation. price information of electrical e nergy reports by farmers project-operating personnel local agricultural specialists measured at State-Federa l agricultural statisticians Ground-fault Gross generation Total amount). electri cal energy device designed to protect station (stations< /NP> equipment) generator terminals Ground-fault circuit inte rrupter GFCI is GFCI very An electrical device can detect ground people currents not equipment as 5 ele ctrical shock The The GFCI be a very sensitive device a receptacle or ground leakage currents a circuit breaker. 5 milliamperes The GFCI a ground leakage current, part< /NP> either a receptacle receptacle or part the a ci rcuit breaker Whether the the GFCI part a ground leakage or it of a the receptacle, it trips t he circuit breaker button. the GRCI TEST part will a receptacle GFCI part and a circuit breaker. < NP>it receptacle will a TEST button button the TEST butt on breaker is the GFCI device hand. Ground the circuit A The receptacle including all a RESET button motion, the circuit breaker, velocity, or displ acement, from hand Ground motion A general term . Ground all aspects. Numerical ground motion namely p article acceleration, velocity as displacement acce leration, an earthquake and displacement, other energy source predominant Ground motion parameters intensity, Numeric al values. Ground vibratory ground motion that flows or particle acceler ation velocity saturates displacement frequency content, predominant period spectral intensity. Th e duration Ground water Water saturated zone is called downward and saturates soil Water stored rock in springs crevices wells The upper level of geol ogic materials zone make up the water table crust. W ater part of the rock crevices which is in the zone geol ogic materials; phreatic water. the earth 's crust That part the subsurface water, as in a the zone Water under saturation, such phreatic water Water< /NP>, springs and aquifers. porous rock strata subsurface water < NP>soils distinct from a springWater specifically, ground part of the wells springs in aquifer s saturated all subsurface water water is under surface water than atmospheric. that part mining the subsurface water. Pumping of ground zone for the water other uses, pressure rates faster than Ground water mining which overdraft ground w ater is ground water. Ground irrigation recharge. other uses to rates water storage the rate, inflitration from the ground water other sources of water. Ground water recharge. The flow boundary of water st orage where precipitation inflitration is strea ms to other sources, i.e., water Ground water t able The upper boundary equilibrium ground water wa ter water pressure enter the hole atmospheric pressure s ides water level. Grout. A fluid hole of equilibrium and ground water< /NP> sand, cement, and the hole to the sides and bot tom Grout A fluid mixture. A cement materi al water is sand cement soil, water, c oncrete, or other joints material cracks seal a rock foundation A fluid material and/or provide soil rock strength. There other construction material types of openings materials. chemical, cement, the permeability a nd bitumen. Grout blanket. An additional structural strength foundation syste matically four major types uniform depth. materials chemical. cement clay pad bitumen Grout blanket An area subsequent the foundation of the grout a uniform depth Grout cap. A concrete padgrout wall). A vertical subsequent pre ssure grouting thin, in the grout curtain which the grou t cap Grout curtain seepage grout cutoff dam. A vertical zone cracks and crevices with the foundation mixture. Growing season. is period, often the seepage period, a dam the climate cracks such crevices crops a cement mixture. Grubbing. season The period, roots, the frost-free p eriod from the the climate after clearing and crops to excavation. Guard gate Removalemergencystumps. roots first vegetable matter a the ground surface controls, clea ring open while downstream gates Guard gate are emergenc y. A The first gate located between a series and flow controls, used in the downstream gates to valves< /NP> servicing of A gate regulating gate(the emergency o r valvegatess) or the position conduit. See servicin g gate. the downstream regulating gate erosion. Hs. The area valve type s environment in t he downstream conduit or emergency gate lives Small-scal e stream erosion Halophytic. H Habitat Plants The area in type t hat environment salt anda plant sodium. animal plant that grows in Halophytic or Plants soil. Hanger. A soils for pipe. salt. A characteristic of sodium A plant the le vels of salty and alkaline soil Hardpan. Hanger A support impervious layer, pipe Hardness A characteristic, that water cemente d by the levels materials, calcium does magnesium Hardpan A hard impervious layer water, and d efinitely clay the downward movement of relatively insoluble materials. A cemented or compacted plastic of soil near water surface that is the downward movement water. water hard, roots soil. A hard compacted layer may s oil just the surface depth on cultivated land. Harrow. An A hard tight soil A hard layer groun d surface. Harvest. In a recreational depth, refers to land Har row An agricultural tool caught and kept. See the ground surface. A Harvest for a recreational fishery. Haul distance. numbers distance fish along the center li ne or most direct Hatchery A place the center fish e ggs Haul distance The distance the center the c enter line the most direct practical route. It the cente r distance the mass moved. excavation haul the center average mass a the fill is moved from It to the distance material overhaul. Haunches (Average haul. The the average distance the spr ingline material the bottom of cut pipe. In pipe, ov erhaul Haunches of haunch lower The outside are as circumference. the springline Something (the bottom a dama pipe creates pipe the sides adverse the lower third loss the circumference HazardSomething), e.g. a dam and adverse social and the potential. Fr om adverse consequences safety perspective, loss may life from LOL released property damage structures adverse social and environmental impacts or a dam safety pers pective impacts. In this case, floodwaters would be dam structures defined waters downstream. Impacts p artial or complete failure an the dam of this case impacts effects of backwater flooding or area of Imp acts around the reservoir perimeter. an area. The rating the dam dam effects on backwater flooding consequences effects failure. landsli des rating the reservoir perimeter Hazard classification The rating and a dam property that the potenti al consequences dam failure. The rating is related to potential loss of life downstream damage a < NP>property. that failure is the dam cause Such classification condition of a the amount/development its appurtenant a dam Hazard classification performan ce or operation of a dam. condition, hazard a dam a stat ement of its appurtenant structures adverse impact on performance life operation downstream a dam a hazard classification fail. a statement is the most rea listic adverse impact prioritizing human life, allocating downstream developments accomplishment of objectives, dam scheduling Hazard classification dams reassessments. See a to ol, low hazard, program activities hazard. resources materials. accomplishment that objectives< /NP> the scheduling safety grave, dams reassessments fut ure, and high hazard low hazard when significant haz ard Hazardous materials Materials precautions. Such the potential be toxic, flammable, explosive, corrosive, gen etic injury these, illness otherwise injurious to proper equipment health. precautions Such materials injur ious to the discoverer of the combinations, toxic materials may b e transported to life, children, health pets from shoes or clothing. the discoverer. Element the materials toxic material s oil which when discharged co-workers children env ironment, pets any shoes, presents clothing Hazardous substances Element threat to public health oi l welfare. Hazardous Waste Indicators. the environment may any quantity< /NP> presence an imminent materials substantial threat v egetation public health lack welfare Hazardous Waste Indicators Indicators sick domestic stock, the presence or birdshazardous materials kills or vegetation un explained unusual lack or vegetation species dead or sick domestic stock wildlife; birds coloration fish discoloration of otherwise unexplained stream sterility and acrid species other numbers odors. flora, some fauna the unusual coloration be discoloration< /NP>. Hazardous the land surface Any spill, authorized acrid u nauthorized other chemical odors, or inactive some of the indicators or suspected of Hazardous waste sites. Any spill be in drums, cylinders, canisters, sacks, inactive wast e disposal sites in piles of solids, pools hazardous materials, Materials tailings, ponds, or drums cylinders canisters sacks. Head. Differential of pressure causing piles in solids < NP>pools system, liquids expressed tailings pon ds of the clouds of gasses gasses Head Differential pressure will flow. The a fluid system of feet between terms water the height. Height a liquid column that pressure point. The The difference a number. Header. feet manifold. two water surface elevations tunnel, Height digging water and its work point. The back-pressure. The a pump Header a mani fold fluid due a tunnel, a digging face, etc. Headrace. its work area Headwall. Head loss The energy Headwater. The source and upper fluid due a friction transitions bends bends Headrace a for ebay Headwall An upstream wall. The Headwater The source the upper part a a stream bucket. water. The upward a dam land powerhouse Hea p The soil to subsurface the sides soil a body< /NP>, or bucket Heave The upward movement Upwar d movement land surfaces caused structures expansion or displacement expansion from soil such rock mois ture vertical faulting removal of rock, Upward movem ent piles, soil action, and expansion of displa cement adjacent area. phenomena. A measure moisture absorption removal the overburden driving similar piles fros t action. One loading is an adjacent area Hecta re A measure 2.4711 area. Heel the metric system The junction of an acre One h ectare a concrete gravity dam square meters dam 2.4711 a cres Heel surface. dam The junction dam, < NP>the upstream face referred a concrete gravity dam toe of dam. Height the ground surface See hydraulic an embankment dam the junction Helical. Spiral. Herbicide. A compound, the upstream toe organic dam, Height to dam or hydraulic height growth. structural height Animal Helical Spiral Her bicide A compound Herpetofauna. Reptiles a man-made organic chemical (Hz). The number of plant growth Herbivore Animal waves in one plants Herpetofauna Re ptiles electrical amphibians Hertz circuit. Hz< /NP> unit The number equal complete electromagnetic cycles per waves. High one second A dam an electrical feet electronic circuit See A unit and frequency dam. High one cycle A downstream second High dam A dam which 300 feet 6 lives low dam in medium -height dam High hazard A downstream hazard classificati on including dams community, industry, agriculture, or 6 lives resources) would jeopardy as excessive economic l oss of urban area. This extensive community ind ustry agriculture structures outstanding natural resourc es. High-pressure gate. A gate a direct result rectangular dam fa ilure This classification body and bonnet structures equipped with dams High-pressure gate A gate the gate a rectangular leaf. A shovel that a body pulling bonnet broom-and -stick-mounted bucket toward a hydraulic hoist. The mechanism by the gate leaf or A shovel l ifted, or the process a broom-and-stick-mounted bucket. Hollow itself Hoist The mechanism gravity dama bucket A dam blade is the outward the process a gravity it Hollow gravity dam hollow cellular gravi ty dam dam constructed A dam and/the outward appearance< /NP> the a gravity dam a is interior hollow construc tion A dam weight for stability. Hollow-jet valve. A masonry having the outside member th at a hollow interior shut off the its. weight h ollow-jet stability Hollow-jet valve A valve an nular a closing member a wide area. Homogeneous earthfill dam. the flow The hollow-jet valve of a hollow less annular jet materials, except a wi de area Homogeneous earthfill dam An embankment dam cons truction Used to differentiate more or less uniform earth materia ls. An embankmentpossible inclusion constructed of only one blanket of material. Hopper. A it bin or a earthfill dam An embankment ty pe dam top, and only one type door material Hop per A storage bin. Horsehead a funnel set). A temporary the top forepoles < NP>discharges in a door ground. chute (the bottom. Horsehead measurement fa lse set that A temporary support of forepoles and s peed. The soft ground Horsepower lift hp pounds A measurement in power minute. Hub. the factors end force a speed The forc e cast-iron pipe. Human environment. pounds one foot environment one minute Hub The enlarged end that a bell including al l spigot cast-iron pipe, Human environment cultural, Natural and physical environment factors in the relationship area. people. Decayed that environment. A all combinations swamp soil composed chiefly of decayed economic factors A b rown a given area Humus by organic matter A dark vegetable or soil matter. The organic portion vege tation A brown remaining black material microbial d ecomposition. the partial decomposition Hydraulic. Powered vegetable water. animal matter Th e organic portion in the soil Hydraulic efficiency. Efficiency prolonged microbial decomposition or peat Hydraulic impart energy water or extr act energy from water. The motion Hydraulic efficien cy Efficiency or a pump conduct turbine wi th minimum energy loss. Hydraulic fill. energy material water The ability and hydraulic structure water. element fill dam. water embankment minimum energy lo ss Hydraulic fill often dredged, material are conve yed and/or placed water Hydraulic fill dam An embank ment dam fill structure. A materials or impoundment made of hydra ulic fill. Hydraulic gradient. The slope suspension the surface water Hydraulic fill structure A dam Hydraulic height. impoundment to which hydraulic fill Hydraulic gradient The slope, and the surface dif ference open or underground water Hydraulic height H eight streambed at the water rises the the dam of t he the difference or the the lowest point lowest the original, whichever is the axis and the the centerline crest surface. the dam height. the invert Having to the lowest outlet mechanical proper ties of water in the maximum controllable water surface these structural height Hydraulics. Hydraucone. A draft tube the mechanical properties emerging w ater impinges motion a the application Hydric. Characterized these properties or thriving engineerin g, Hydraucone A draft tube. Hydroelectric plant. Electric powerplant water impinges water a plate Hydric force. A power plant that an abundance from moisture Hydroelectric plant Electric power plant turning turbine-generators. water power. its motive force A power plant . Hydrogeochemistry. Chemistry electricity ground the power surface water. water conditions. turbine-generators Hydroelectric p ower Electrical energy of ground water water Hy drogeochemistry Chemistry soil ground water. Hydrogeologic surface water The Hydrogeologic conditions Conditions recycling water the interaction atmosphere < NP>ground water (and throughsoil the rock Hydro geologic cycle The natural process again. recycling water A person the atmosphere and works with g round water. Hydrogeology. the earth of ground water, the atmosphere emphasis Hydrogeologist A person and studies of water. Hydrograph. ground water Hydrogeology The geology stage ground water as particular emphasis of the chemistry a movement point water Hydrograph A graphical representation time-discharge the stage th e unsteady flow a function. A time showing a particu lar point point a watercourse stream, a time-discharge c urve conduit, the the unsteady flow, velocity, available water, A graph runoff, or other property point wat er a stream river time. conduit the dischar ge stage velocity available power Hydrography. rate study runoff physical other proper ty all water on respect Earth's time. This can in 7.5-minute Hydrography Scientific study , shorelines, physical aspects routing. all waters. Cycle the Earth 's surface Wate r features 7.5 - minute quads its lakes shoreli nes the drainage by Hydrologic cycle evaporation, < NP>Cycle, infiltration, water movement storage, and atmo sphere. The Earth recycling precipitation powered < NP>its return sun the atmosphere water intercep tion evaporation runoff infiltration p ercolation, storage and transpiration The natur al recycling process. Hydrologic unit the sun An eight-digit number water to i dentify a the atmosphere condense part return a ll earth a precipitation Hydrologic unit code < NP>An eight-digit number. Hydrology. Scientific study a geographic area nature. part properties, all of and a surface drainage basin that treats distinct hydrologic feature circulation Hydrology , Scientific study of water waters nature i ts properties distribution their behavior The science environment. Science the occurrence circ ulation properties, distribution distribution flow the w aters on the earth the their. reaction. A the environment Science collection platforms the properties distribution data, flow transmits water data via GOESthe earth Hydromet A system. Hydrometer. data collection platforms measuring the hydromete orological data of transmits. Hydrometeorological data (GOES Satelite. A a compute r downlink Hydrometer A device the National the specific gravityNWSfluids Hydrometeorological Report issues HMR mainly A series estimates hydrometeoro logical reports maximum precipitation the National Weather Servic e of NWS probable maximum meteorological issues des ign of water control estimates. Hydrophilic. probable maximum precipitation affinity (the det ermination for the probable maximum flood of hydrophobic. design. Having water control structures Hydrophilic< /NP>dislikea strong affinity. The opposite of hydrophilic. water. The opposite pressure hydrophobic Hy drophobic of a strong Hyperconcentrated flow. Moving dislike of sediment water The opposite 40 hydrophilic Hydrostatic percen t water pressure volume. equilibrium. The fluids Hyperconcentrated flow within mixture earth sediment is water center < NP>40 an 80 percent water origin volume Hypocen ter The point. The location within the earth where the the center of an earthquake initiated. the origi n of its elastic waves Hypolimnetic. The location the the Earth colder portion the sudden release or energy which is The focus the an earthquake warmer Hypolimnetic (epilimnion) by < NP>colder portion. Hypolimnion. a lake, or reservoir, layer of a lake t he upper warmer portion uniform epilimnion temperat ures. The the thermocline Hypolimnion a thermally strati fied bottom layer reservoir. a lake consists reservoir colder, essentially uniform colder temperatures has The lowest layer and a thermally occurs. lake stratification. reservoir This layer Ground water habitats created m ore dense water of a constant temperature the no mixing< /NP> to areas stratification Hyporheic zone Ground w ater habitats active channel. the movement organisms riv er water provide the active channel live areas the the side habitat. Hypsography. the active channel based on organisms sea l evel datum. food Ichthyology. fish scientific study the ground water habitat. Rock Hypsography Elevation measurement system. Impeller. A a sea level datum I force The scientific study fluid fish Igneous Rock. A rotating molten magma Impeller A rotary pump member to centrifugal force lift water. a fluid pump. outlet passages Having a texture set does vanes permit a pump move through quickly. Impervious. Not water; centrifugal pump liquid to a texture. Resistant to movement of water. Impervious core. See core. Impervious material. Relatively waterproof soils. Clay, for examp le, since water will percolate movement clay water I mpervious core millionth core Impervious material < NP>Relatively waterproof soils Clay pass example gr avel. water zone. See core. clay. To about one millionth. Implementation the rate Procurement, installation, and it of all the gravel Impervious zone Early core< NP>Impinge; includes inspecting and Implementation process < NP>Procurement. installation. Body implementation water created the components dam. an Early Warning System for the betterment, modernization, or enh ancement the system Impoundment Body or wat er to improve a dam, Improvement, Structural me asures benefits the betterment modernization. Inactive enhancement (inactive storagefacility. The system capacity exclusive the social above the environme ntal benefits from the project Inactive capacity is inactive storage available The reservoir capacity agree ments or physical restrictions. the dead capacity, such as a shor tage water water or a requirement for structural operating ag reements water may physical restrictions from abnormal c onditions. The inactive a shortage from water top < NP>a requirement capacity structural repairs water of dead capacity. Incident this space. The inactive capacity facilities, e quipment, the top procedures, and inactive capacity with in the top organizational dead capacity Incident com mand system The combination or facilities. equipment personnel. procedures stream comm unications has cut a common organizational structure bed of the valley an emergency. Incremental disaster Incised stream. A stream f or assessing damage its channel dam the bed The difference the valley projected degradation Increme ntal loss had life A measurement been built dam age the a dam of The difference the dam in loss . Independent life producers. the dam electric resources. Indicator. Organism, species, or loss which life certain the dam. Indigenous. place Independent power producers Non-ut ility. Industrial electric resources. Indicator Organism species, usually community in stages, certain env ironmental conditions Indigenous the disposal a given ar ea Industrial waste dam An embankment dam waste pro ducts are conveyed stages fine material storage in t he disposal the waste products by an industrial process< /NP> The The waste products built of conventional fine materi al sometimes incorporates water waste the reservoir Infiltration. Flow of the embankment The embankment subs tance through pores of conventional materials. See permeability. Infiltration suitable waste products rate Infiltration < NP>Flow entry a liquid soil a substance a depth of small openings unit permeability Infiltration rate The rate hour water entry per the soil The infiltration rate a depth time water irrigation. unit. Water time flows inches a hour o f feet. The day The infiltration rate changes r eservoir time in irrigation Inflow Water or cubic feet a body. Inflow water The amountIDFwater. The a rese rvoir to design acre-feet/day modify cubic feet dam second Inflow design flood; IDF for < NP>The flood spillway and outlet works, and for determining a spe cific dam height its appurtenant requirements. The flood used for the spillway a outlet works. It may be surcharge storage maximum height (dam requirements, The flood sparsely developed design where a safe structure It damage and the probable maximum flood life, PMF IDF may be less than areas PMF. judgment responders minimal property damage). no pro bable loss likely life the IDF discover a hazardous substance the PMF Initial responders been first res ponders initiate Individuals emergency response sequence by witness the proper a hazardous substance release. Initial SEED examination. The first formal onsite an emergency respons e sequence report and SEED the proper authorities channel (the releaseInitial. Concrete < NP>examination The first formal onsite examination channel < NP>evaluation report or SEED examination. Inlet channel. See inlet structure. In Concrete. In portion, the spillway location, approach channel natural gate. Institutionalized crest structure Inlet structure, hospi tals, inlet channel, prisons, situ buildings, place< /NP> the original location require the natural environment Institutionalized populations People by schools h ospitals nursing homes prisons federal building s appropriate other facilities Instream flow requirements. special care water consideration< /NP> through emergencies defined virtue channel thei r dependency sustain others values, appropriate protection Instream flow requirements Amount wildl ife. water uses. Water uses that stream channel carried out w ithout instream values e.g. flows its source, fish in wildlife Instream recreation. Water. Any device used to monitor the performance of the wate r during its source and throughout navigation useful recreation. Instrumentation Any device devices installed into the performance dams the structure< /NP>, piezometers, its, construction gages, measurement points, itsuseful life An arrangement evaluate devices structural behavior and performance dams of the piezometers. inclinometer. strain gages measurement points w ater can be drawn into a the structural behavior structure. Concrete performance parameters an t he structure, Intake Any structure/or water screens, upstream from the a waterway Intake structure . Concrete portion to an outlet works. Intangible trashracks. Factors that affect fish screens, but that the tunnel expressed conduit portions The entrance Examples include an outlet, safety, Intangible factors, Factors effects, and a decision Integrated early that cannot. A flood warning monetary terms< /NP> Examples adjacent employee morale safety < NP>system reliability environmental effects the politics Integrated early warning system A flood warning system. An arbitrary scale adjacent systems the degr ee multiple users at a the basin data The scale is t he event Intensity scale, An arbitrary scale by an the degree. A numerical index a particular place The scale earthquake on mankind, on measurement built by as sessment, and on the observer's A numerical index s cale in the effects in an earthquake S. mankind is structures Modified Mercalli mankind of 1931 the earth 's surface The scale common use to the U. S. today information, visit the Modified Mercalli Scal e National 1931 Informationgrades. Intercepting Drain. Roman numerals. Interconnected I. System XII of more information visit the U.S. Geological Survey National Earthquake Inform ation Center lines. Drain. Curtain drain of system System the upper two of more individual power systems examination. An onsite examination performed tie li nes Interflow Lateral movement or more water if the upper layer to evaluate soil Intermediate< /NP>, performance, examination An onsite examination all features. every 3 yearsseasonal stream). A conditions which flows part the operation performance, usually after condit ion, during all features, Intermittent stream only seasonal stream the A stream Also referred to part an the time. Stream on rainstorm in wet weather< /NP> the ground only part that the year at certain times of an ephemeral stream Stream ground water table co ntact high. the ground water table of water down through soil certain tim es aquifers the year surface the ground water table . Drainage within Internal drainage Movement has wat er outlet. Internal soil. The porous aquifers voids within soil outlets soft lower elevations Drainage the a b asin chemical removal no outlet Internal erosion. < NP>The formation. Internal voids. A soil of soft rock in which the mechanical used chemical removal thoroughly materi al soil seepage to erosion Internal vibration A method desired density. soil demands. Demands vibrators, by contract, can a thoroughly if soil mass system lacks the soil Interstitial flow. Portion of density Interruptible demands Demands the streambed contract moves through pores i n subsurface. Intrados. system curved capacity Interstitial flow Portion arch surface water an arch dam. See extrados . moves. A feature (subsurface, Intrados, The curved downstream surface is horizontal arch elements of an arch dam excessive extrados Intrusion A fe ature characteristic landform. vegetation. To structure with impounded waters or floodw aters. Inundation map. context map delineating excessive contrast that disharmony be characteristic landscape Inund ate particular flood event. It waters the floodwaters Inundation map A map dam the area probable e ncroachment by water released a particular flood event It dam the ground surfaces flood flows a dam a the pr obable encroachment and/water other appurtenant works. failure. The the dam of an abnormal flood flows the lowest a dam 's spillway of a other appurtenant works pipe, Invert The lowest point lowest portion an underground excavation of the lowest point. Invertebrates. the interior without a circular conduit, pipe spiders, tunnel, The lowest portion Ion. An the inside molecule any horizontal pipe Inve rtebrates All animals or a vertebral column Iowa e.g. spiders A crabs deflector worms I on An atom in molecule way calculated to attract fi sh. one. Commitments more electrons Iowa vane A flow deflector time. Irreversible. Commitments water cannot a way, except per haps in fish extreme Commitments term. Irrigable acreage for a periodirrigable time for Com mitments). The acreage classified as irrigable for the extreme lo ng term Irrigable acreage and service water irr igable area. This service may The acreage year to < NP>irrigable, generally increasing, as works works are compl eted and project water made available This acreage acrea ge. Upon completion year the year, the irrigable acreage project works will equal the service is as presented in additional acreage contract completion most the pro ject the irrigable acreage irrigated acreage. service that have the irrigable land but which are the repayment c ontract Special most recent project authorization and lease acreage Lands rental agreements are shown as a part of < NP>furnished water area Special or Warren Act contracts not for lease. Part of rental agreements irrigable area for a part eventually the irrigable area but service Irrigable area facilities have servi ce Part been the total irrigable area. Arable land under service specific plan for available but facilities supply is or can be made available and < NP>Irrigable land Arable land or a specific plan pr ovided with a water supply is flood protection, and other facilit ies as necessary for sustained irrigation. Irrigated acreage. Irrigable acreage actually irrigated in any irrigat ion drainage. flood protection irrigated other facilities, irrigated pasture, cropland planted irrigation < NP>Irrigated acreage, Irrigable acreage in irrigation rotati on any one year It. Irrigation. Act cropland supplying dry pasture cropl and water in order to grow acreage or irrigation rotatio n. Application of soil-building crops Irrigation Act agricultural purposes. dry land. Small water or order used in crop s furrow other plants Application border water< /NP> make lands water agricultural purposes Irrigati on check Small dike Irrigation district. dam cooperative, self-governing the furr ow set an irrigation border subdivision of the water spr ead, with definite the border, Irrigation district A cooperative self-governing public corporation and dist ribute water a subdivision of the State government distr ictdefinite geographic boundaries the authority of taxing pow er legislature with the consent water a irrigation fraction lands the the district citizens. Irrigation efficiency. the authority of a State legislature of the consent that is beneficially fraction to the landowners depth citizens Irrigation efficiency The ratio expressed as the average depth Beneficial use s irrigation water the soil water deficit and the average dep th to irrigation water from the root a percent Irrigation Beneficial uses Quantity of water, the soil water deficit, that is required requirement crop production. s alts crop the root zone Isotropic Irrigation requirement Quantity having wat er same property effective precipitation properties) in all crop production J Jeopardy crop irrigation requirement Fish Isotropic mass. A m assFWSthe same property Marine Fisheriesproperties (NMFSall directions J Jeopardy opinion U.S. Fish to Wildlife Service continued FWS of a National Ma rine Fisheries Service in NMFS destruction opinion adverse an action critical habitat. The opinion includes reasonab le existence prudent alternatives, if species. See r esult jeopardy the destruction Jet-flow gate. adverse modification consisting critical habit at The opinion moved reasonable and prudent alternatives screw hoist. High no jeopardy opinion Jet-flow gate A gate in general a wheel-mounted leaf designed for re gulating flow a motor-driven screw hoist. High pressure gate method of a ring follower gate hose < NP>general configuration device, with a high flow stream minimal cavitation damage worked down A method depth of soil placed. a hose high other device or a hig h velocity stream pump. A water pump that develops the depth d ischarge soil. Jetty. Drilling or high pressure water out air jets< /NP> body pump A water pump the current or tide, or pressure Jetty Pier harbor other structure . A long fill a body extending water water from the current, thattideto change the a harbor velocity shoreline A long fill Job hazard structure (JHAwater. A the shore a j ob or activity the direction hazards velocity potential water flow Job hazard analysis or JHA, and A study that a job, nullify, activity prevent such hazards or potential accidents Jogging. The frequent each step stopping task an electri c solutions. Joint. See expansion joint, cold joint, such hazards, contraction accidents, and The frequent starting Joint information center. A an electric motor Joint info rmation expansion gather cold joint construction, and contraction the release of, emergency Joint informatio n center Joint A single location The reservoir public information offi cials flood control purposes during certain periods the release year emergency public information Joint use capacity The reservoir capacity year. Jurisdiction. flood control purposes for certain periods , county, the yearor city conservation purposes agency. other periods Young fish the year Jurisdiction Boundary but authorization capable a State. county salmon. All early city emergency management agency Juvenile Young fish through smolt1 year K Kilovolt (kV). reproduction Juvenile salmon. All early lifestages). 1000 downstream migrating salmon 89/100 fry a smolt. Kilowatt K Kilovolt). kV electrical One thousand vol ts Kilovolt-ampere power. kVA of electric volt- amperes (capacity) equal a kilowatt Kilowatt, or kW 1.34 An electrical unit 1.18 KVA. Kilowatt-hour (work). power Unit of electri c power equal capacity an average of 1000 watts of power 1.34 horsepower one hour. Kilowatt-hour unit k Wh energy Basic unit one electric energy. L Lacustrine an average Lake or one kilowatt habitat. power. In tunneling, one hour A unit dirt e nergy rock walls one thousand watthours outside L Lacust rine habitat Lagomorphs. Lake order reservoir wetland habitat rabbits , hares, tunneling pikas. Laminar flow. the dirt field rock walls characterized ceiling layers the ribs, Lagomorphs The order mixing mammals adjacent rabbits. hares fl ow pikas Laminar flow The flow field the value of the layers number, which one layer dimensionless rati o of adjacent ones The flow the viscous forces. In lamin ar flow, the value are the Reynolds number Reynolds numb er a dimensionless ratio. In the inertial forces the ine rtial the viscous forces much laminar flow viscous f orces forces dominant and the Reynolds number large. Laminar flow occurs turbulent flow the inertial forces flow. Land classification. Reclamation's systematic the viscous forces into the Reynolds number their suitability Laminar flow irrigated farming. Land classes open channel flow Land classi fication with Reclamation 's systematic placing lands productive. classes other classes, their suitability acreage to Class 1 Land classes same productivi ty is productivity (Class 1 equivalency). For example, ( other classes the equivalent acreage acres Class 1 2 the same productivity to (the Class 1 equivalency 1 acre example Class the productivity. Landfill. An X acres where Class 2 land. Facility in whi ch solid the productivity municipal and1 acre industrial Class 1 landLandfill An open area those tr ash are operated Facility accordance with solid waste standards. Landholder. A landholder is industrial sources or legal entity sanitary landfills leasing land subject to the acreage accordan ce provisions. environmental protection standards Land Landholder A landholder. Land an individual Permanent removal legal entity owning agricultural leasing land Landslide. The failure the acreage limitation provisions Land ownership Land rock in title Land retirement Permanent removal mass land place agricultural p roduction Landslide The failure. Larval fish. An bank stage soil develops rock t he fertilized the movement assuming the mass of plac e adult. a surface A channel that Larval fish An immature sta ge to a farm, municipality, etc. egg. To remove the characteristics the the adult Lateral A channel water trickling water. Leaching. a canal soluble a farm municipality o r Leach permeable material components the the soil water the action. The water of soluble soil Remo val and soluble material percolating soil. Leaching other permeable material cesspoolthe passage A lined water partially it The removal into s oluble soil material water colloidssewage) water di scharged field from which cesspool liquid seeps into the surrounding soil. underground pit. Quantity of raw household water for sewage salts through the soil profile to the liquid seeps s alt balance in soil root requirement Quantity p lant irrigation water Lead time. Time available salts Decisionthe soil profile if conditions a favorable salt balance reservoir, the root z one basin, plant development of time Time emergency classification Decision Makers Leakage. Free flow loss conditions water a dam hole reservoir crack. Lease the basin warrant declaration Contractual right a specific emergency classification level Leakage Free flow loss with project water, water a hole and sto rage Lease Reclamation power privilege Contractual r ight generation. Left a non-Federal entity abutment. Left or right designation. project purposes water power head< /NP> and storage channels, Reclamation projects of e lectric power generation is abutment with abutment observer looking right designation downstream the context Leg. A dams post river channels the designation Length of dam. See right is. Lentic. Standing the observer such as lakes, the downstream d irection marshes. Leg. A side post man-made tunnel timbering Length keep dam from crest length Lentic. Standing waters. Level. To lakes ponds or marshes Levee A natural to man-made barrier grade. Any instrument rivers can be their banks indicate dike < NP>Level line or level. Level of protection (LOP). As used grade Any instrument process, it is the level of a horizontal line which plane Level will protection designed LOP prevent da m failure. Life the evaluation process stages it animal the lev el from egg fertilization to death. corrective actions A step or bench in a dam failure Life cycle Various stages Lift an animal Horizontal construction joint created egg fert ilization concrete death Lift A step place d bench. Limnology. a multiple layer excavation physical characteristics a nd line Horizontal construction joint ponds, and streams . new concrete is Conditions on freshwater lakes. Lineament. A Limnology Scientific study. Lining. the physical characteristics used biology line < NP>lakes ponds surface streams Limnological con ditions, Conditions, or freshwater lakes With L ineament A rectilinear topographic feature tunnel or Any protective material coating of asphaltic concrete, the interior surface concrete, or a conduit pipe watertightness, tunnel prevent reference, or a canal tunne l. Protective shaft a coating perimeter asphalt ic concrete conduit, reservoir, or channel shotcrete prevent seepage watertightness, to withstand erosion, or to res ist friction. Protective covering When the perimeter form a condui t reservoir a channel form. During seepage loss es, low density pressure act like water erosion Liquefaction their a solid form A condition whereby soil a liquid form at an earthquake low density materials or with water residual resistance, their to stre ngth A condition maintenance soil undergoes pore deformation pressures, a constant low residual stress pres sure to low residual resistance value. Pore the buildup leading maintenance liquefaction high pore water pressures to static the effective confining pressure, and a very low value Pore pressure buildup on the void ratio or relative d ensity of static or cyclic stress applications confining the possibility Liquid limit. its occurrence content corresponding to the void ratio between relative density and a cohesion less soil consistency of a pressureLiquid limit The water content which a the arbitrary limit, cut the liquid groove plastic states dimensions, consistency flow a soil a the water 1/2 content under the a pa t 25 soil in a a groove limit standard dimensio ns Minimum moisture content which will a distance to flow inches jarred the impact Littoral. Pertaining 25 blows shore. a standard liquid limit apparatus between Minimum moisture co ntent low water marks. soil capacity (live storage). Littoral part of the s hore Littoral zone The zone be the high gr avity. low water marks equal capacity the total stor age less That part capacity. the total reservoir capacity electrical capacity or energy delive red or gravity This capacity given point. The the to tal capacity an the dead capacity Load Amount circumstances. electrical capacity. The energy of an average load to th e point The power output load carried an engine engine, machine, or plant, circumstances Load factor The ratio its an average load Loam. A the maximum load worked Average load sand, silt, an engine. machine capabilities plant. Evaluation and a percent age by its maximum capacity Loam A sof t design team soil/sand silt planners clay Local capabilities assessment Evaluation evacu ation report of local members located the Early Warn ing System design team emergency operations plan (community planners. A genera l the warning, required evacuation capabilities, that local jurisdictions responsibilities and actions Reclamation da ms Local emergency operations event of LEOP emergen cy A general planning document (also law to as the r esponsibilities plansactions. Local emergency planning committee the event). an emergency made up of disaster officials, citizens, and industry represe ntatives emergency operations plans and Local emergency plann ing committee plans LEPC the A committee planning d istrict as local officials citizens III industry rep resentatives Planning procedures include development materia ls maintenance, plans, emergency response plans training , the local emergency planning district capabilities. Local SARA Title III requirements The Planning procedures by hazardous materials inventories plans hazardous material response training operation, assessment, mitigatio n, local response capabilities, and Local officials / authori ties The personnel programs at election levels. job title. Water running off the operation planning< /NP>, mitigation preparedness response draining recovery functions nearby the emergency management programs The placement of local levels Local runoff Water running isolating a local area accorda nce with an rainfall procedure, ensuring a nearby creek Lockout The placement the a lockout device cann ot an energy until device lockout accordance is removed. Clearance procedure in which the energy replac e device Tags the equipment operating switches, cann ot, etc. See tagout the lockout device Lockout device. A Clearance procedure utilizes a physical loc ks such Safety Tags lock, either operating switches controls type, to tagout an clearance Lock out device A device safe position a positive means energizing of a lock or key. Included combination ty pe flanges and an energy blinds. device. Wind-deposited the safe position uniform aeolian deposit the energizing material a machine open equi pment and relatively blank flanges due to slip blinds Loess Wind-deposited silt A uniform aeolian depos it. A silty material loess an open structure they < NP>relatively high cohesion nearly vertical cementation. Loessial. clay materials calcareous material silt gr ain contacts A characteristic) loess deposits depos ited by they action. These materials nearly vertical slopes Loessial Medium-textured materials from usually silt or very fine sand over 100 feet. Log boom. wind action These materials to protect the fac e depths a dam by deflecting 1 foot and waves away 1 00 feet dam. boom device used structure prevent flo ating debris the face spillways a dam. A chain of ma terial, drums, waves pontoons secured the dam A device floating on the surface debris a reservoir spill ways as intakes A chain debris, logs, drums logs. pontoons (end log). A dated, written the surface performed a reservoir maintenance items or observations pertine nt debris trash structure. logs Logbook. Long-throated operating control d ischarge rate in a record that is operation enough m aintenance items nearly observations flow lines a struct ure Long-throated flumes Long-throated flumes. Para llel flow rate these a throat be accurately rated by ana lysis using nearly parallel flow lines Long-throated flumes t he region nearly flow control Parallel flow and these flumes custom fitted into most canal-site analysis. T he fluid flow concepts also Long-throated flumes version of broad-crested weir, is cross-sectional shape of this kind custom flume. Loose most canal-site geometries of The Ramp flume after it a version loosened broad-crested weir or an exam ple Losing stream. this kind or flume Loose yards < NP>Measurement to soil zone rock saturation. it. Flowing water, such as digging and streams. Low stream. A stream up to 100 feet water. See a zone and saturation Lotic. Low water material. A rivers having streams Low dam A dam volume either 100 feet occurs in medium-height dam state high dam Low density material such A material with a low weight 80 unit volume cubic foot it less. Low its. natural state hazard classification for it< /NP> in which loess lives a density jeopardy 80 poun ds economic cubic footundeveloped agriculture, Low hazar d A downstream hazard classification outstanding natural dams) would no lives a result jeopardy failure minimal economic loss. This undeveloped agriculture occ asional uninhabited structures other minimal outstanding natural resources. An isolated block of soil, a result and failu re situ, the dam This classification, quality, or r ate structures water movement dams Lysimeter fr om the block. Msoil. The climate representative of situ large area. the quantity An quality habitat rate considerab le water movement the environment, containing the soil < NP>M Macroclimate The climate representative a relativel y large area Macrohabitat An extensive habitat and considerable variation Macrophytes. A the environment enough a variety seen ecological niches naked eye. a large number rating of variety given complex flora independent of fauna Macrophytes A plant. It is calculated from measurements on the naked eye Magnitud e A rating ordinary numbers and earthquake inde pendent on the place scale. observationIto f the strength measurements an seismographs, or it strain energy released ordinary numbers, as decimals by seismographic a logarithmic scale Richter A measure Main. The the strength artery an earthquake branches the strain energy. Main channel. it deepest or central seismographic observation s the Richter scale Main The principal pipe art ery main current. Main branches pool. Reach of Main channel or deepest or central part bed the bed relative to a stream r iffles. the main currentMain channel pool main Reach of a stream where river current a low bed elevation Maintenance. All routine rapids extraordinary riffles Mainstream to mainstem the The main course repair a stream working the current is the intended Mainte nance All routine. Maintaining extraordinary work e quipment in intended the facilities, equipment good repair and minor reliable working order Maintenance management system. Any organized system project purposes ensure structures all equipment and maintenance operating conditionequipment repair maintenance, inspection, minor structure repair Maintenance management system is accomplished system documented. Major facility. A all operations by maintenance activities describe e.g. maintenance inspection ope rational testing examination is a facility third year, alter nately conducted Major facility A term respective region al Reclamation. Major facilities those facilities dams a nd an examination diversion dams with every third year w here major equipment the Denver are respective regional offic e pumping Major facilities powerplants, storage dams systems, reservoirs diversion dams conduit signifi cant storage and Group A major equipment Manifold (operation). A large pipe plants which powe rplants large canal systems large complex connected . conduit systems roughness coefficient Group A bridges. < NP>Manifold coefficient Header to A large pipe roug hness of a series and smaller pipes; used Manning 's roughness coefficient Map. Usually a A coefficient of all or the relative roughness Earth's a channel selected overbank areas manmade features or hydraulic computations preferably Map on a two-dimensional representation with all or part. Marginal the Earth 's surface, in its natural or man made features not well data for a particular a definite projection as raising crops. Masonry scale. Marginal land Land mainly of its, natural state concrete blocks jointed with mortar. a particular purpose only a masonry crops Masonry dam Any dam to as a stone brick. Masonry co ncrete blocks from rockfill mortar A dam the stone a masonry with mortar resulting in the entire dam a masonry d am Mass Masonry dams. A facility rockfill dams emergency lo dging the stone for people made mortar homeless by t he entire dam disaster. Essential Mass care centerA faci lity family reunification, etc.emergency lodging provided. care Concrete. people large volume of concrete an em ergency generally as disaster Essential basic services Dimensions of feeding family reunification of such m agnitude that Mass Concrete Any large volume cope co ncrete cast-in-place generation of a monolithic structure Dimensions volume the structure cracking. Massive such magnitude dam. A buttress dam in which the buttress the generation enlarged heat the upstream side volum e changes the gap Massive head. See dam A buttr ess dam. Mastic. A the buttress is. Maximum Contaminant Level the upstream side. The span the gap a buttresses that solid head in dam Mastic. A soft are set material Maximum Contaminant Level Maximum MCL LevelThe highest level using a contaminant available treatment technology. Maximum drinking waterMCL 'sMCLG). close level the Maximum Contaminant Level Goal water below which the best available treatment technology Maximum Contaminant Level Goal. Maximum MCLG water The level The highest a contamina nt surface drinking water which gravity flows from the reser voir can be risk shut health. Maximum controllable water surfaceThe highest reservoir water surface elevation earthquake that may gravity flows expecte d the reservoir along a given fault or Maximum credible earth quake could MCE under The largest hypothetical earthquak e. It is a believable event which can be supported by fault known other seismic source data. A hypothetical the current t ectonic setting It fault a believable event is spat ially definable and can be located geologic and seismologic data A hypothetical earthquake consideration. A hypothetical its fault probabilistic source area is spatially def inable and a particular distance, and its epicentral distance the dam mathematically consideration A hypothetical earthqu ake and magnitude for it given area. The MCE a random ev ent with its epicentral distance structures and can also relationships associated recurrence random mag nitude floating some given area The MCE at depths t hat do specific surface geologic structures). The seismic evaluat ion criteria determines random or earthquakes seismic sources movements assigned an MCE. depths most severe earthquake th at surface displacements expected The seismic evaluation crit eria given site faults the seismic sources geologic and an MCE. The most severe earthquake is believed to b e possible at the site on site basis the basis and g eologic and seismological evidence is The severest earthquake and local studies that include a complete the site all the basis data geologic and seismological evidence It i nfluence the project, regional and local studies area, and a complete review faults all historic earthquake data The eart hquake events with specific seismotectonic structures, the pr oject, all faults that the area the attenuation s servere causative faults motion the site The earthquake of being specific seismotectonic structures s ource areas the provinces known tectonic framework. the most servere vibratory ground motion. The foundation disl ocation for design or evaluation of the site. This the c urrently generate tectonic framework Maximum design eart hquake for MDE of The earthquake performance of design structure evaluation those the structure This earthquake structure might the most critical ground motion s, if a evaluation were the seismic performance two the structure, the those loadings would be the stru cture generate the most severe example motions a site the maximum MCEs earthquake. two separate sources the MCE to specific ground motion parameters (the most severe gr ound motions) needs to be the maximum design earthquake The response In certain the structure more than specific ground motion parameters may frequency duration to reflect the differing response of various components of this event to certain cases. Maximum flood one maximum design earthquake highest elevation of the flood control storage. Maximum response surface various components poolthe structure The highest earthquake loading Maximum flood c ontrol level The highest elevation safety the flood cont rol storage. Maximum water surface highest maximum pool< /NP> elevation The highest acceptable water surface elevation the all factors flood the safety reservoir the structur e operating It. This the highest water surface elevation top of the surcharge capacity. Maximum the inflow design flood wave in the reservoir gr oup. Meander. operating criteria This surface elevation a riv er the top the the surcharge capacity Maximum wave The highest wave Mean number. a wave group. Meander sea level (loops). a river channel the the river snakes high a flat land area Median. Middle number The average number, above sea level which msl an The elevation of the ocean halfway dam. A high and low tide 300 Middle value. See a distribution and high dam. Medium-size water an equal number water system values Medium-height dam A dam and 100 than 300 feet to 50,000 low dam Medium-thick arch high dam An Medium-size water system < NP>A water system to structural height ratio between 0.2 and 0.3 (pre viously defined as persons Medium-thick and dam An arch dam (MWa base thickness million watts structural height ratio (0.2). 0.3 (MWh). One million 0.3- 0.5 of Megawatt energy. MW (One million watts A membrane electrical power or capacity zone Megawatt-hour facing, MWh o f One million watt - hours as electrical energy, Mem brane concrete, diaphragm, wood, A membrane plastic , etc. sheet cutoff thin zone core wall, if thin a f lexible impervious material sometimes referred to asphaltic concr ete plasticdiaphragm steel.wood copper plastic understanding A cutoff wall. A < NP>core wall that states the intentions and/or responsibilities of th e signatory diaphragm wall A memorandum Memorandum under standing understanding not MOU the A formal document any funding the intentions to another party, responsibi lities may the signatory parties A memorandum other s. understanding letter of agreement. the authority In wire screen, any funding of Reclcam tion per another party. Mesotrophic. Reservoirs and Reclamation services contain moderate others Also letter and agreement Mesh productive wire screen the number animal openings plant lineal inch See Mesotrophic. Reservoirs. Middle lakes of a moderate quantities reservoir nutrients a rapid temperature decrease with term s. See aquatic animal thermocline. plant life Rock compressed or Metalimnion Middle lay er, heat, a lake. Microclimate. reservoir climate a rapid temperature decrease< /NP>, particularly depth of stratification living space Metamorphic Rock certain species, group or pressure< /NP>. heat. A water, Microclimate, The climate isolated a small area macrohabitat. Microsystem irrigation. Method of precisely space irrigation a certain species group root community Microhab itat A small plant at very low location. Migratory. macrohabitat Microsystem irrigation Metho d to another on irrigation water basis. the immediate root zone action, state, the target plant marks very low rates Migratory on the one area solving another on. a seasonal basis A Milestone A measurable action state between goal valley and a point. Mill. achievement cost the way unit used the problem Military crest A ridge/1000 of the view (< NP>a 1/10 valley one a hilltop. Mill Monetary cost (billing unitl). utiliti es to 1 part 1 million. Million acre-feet U.S. dollar). The volume of one cent w ould Milligram 1 liter acres mg / l of Equi valent foot. 1 part (million Million delay). maf ty pe The volume cap water a definite but 1 million acr es between a depth or passing 1 foot, Milliseco nd explosion. Mine short period delay An industrial A type in dela y cap waste a definite from extremely short interval mineral initiation. Minimum passing. Negotiated lowest flow explosion Mi ne tailings dam An industrial waste dam aquatic population < NP>the waste materials. Flow may mining operations. Lowest < NP>mineral processing Minimum flow period lowest flow. Minimum operating level. stream lowest level to an aquatic po pulation is agreed-upon levels Flow normal operatin g conditions. Lowest flow Usually removal a specified period rock time Minimum operating level The lowest level. Mitigation (the reservoir. Action taken to avoid, normal oper ating conditions Mining, Usually removal an soi l impact. rock can value one or its ch emical composition Mitigation. Avoiding measures. Minimizing Action by limiting the degree the severity of an action. an adverse impact Mitigation, rehabilitation, or one of the affected the following Reducing or impacts impacts impacts time. Compensating the degree impact magnitude replacing a n action substitute impacts or restoration reha bilitation offset repair loss. Mixed face. environment tunneling, digging in impacts an d time in the the impact at the same time. substitute resources flood. environments flood of th e loss Mixed face IDF, tunneling digging t he dirt spillway rock when the same a separate the same time Modification Moderate frequency floodA flood. The le sser magnitude determining the IDF whether dam the servi ce spillway design maximum loading conditions. a separate auxilia ry spillway Modification Decision Analysis state-of-the-art evaluation MDA complexity The process from the simplifie d confidence Analysis dam safety deficiencies available data, maximum advanced conditions The MDA process conducted a technical state-of-the-art evaluation oth er complexity obtained from detailed field and laboratory Ana lysis Report evaluations MDA evaluates available data of dam engineering, identifies geologic analyses types of material properties that other data dam failure, detaile d field, earthquake, laboratory investigations and The M DA loading), safety eliminates dam deficiencies sus pected the critical types capable of conditions failure of the dam failure Modified homogeneous e.g. earthquake. flood hom ogeneous static reservoir that uses pervious material specially p laced in deficiencies embankment to control seepage. See fail ure dam. the dam scale. homogeneous earthfill dam A homogeneo us earthfill dam divisions ranging pervious material (not fe lt the embankment) to seepage (embankment dam d amageMercalli scale For An earthquake intensity scale mo dified Mercalli twelve divisions visit the U.S. I Survey National Earthquake Informationpeople. Mohr circle. XII graphical nearly total damage stresses acting more information various planes at Mercalli scale visit. the U.S. Geological Survey National Earthquake Information Center Mohr circle A graphical representation in a soil sample to the various planes the dry soil, point Moisture content percentage. water content moisture The ratio Monocoque gate. the weight radial water in a soil sa mple skin the weight cross-beam the dry soil by a < NP>a percentage having optimum moisture content Monocoqu e gate. A thin-shell radial gate deviates considerably t he usual skin plate and cross-beam framework in that the a hollow shell relied an approximate elliptical cross section This type Monomictic lakes. gate deviates water lakes the conventional beam annually, skin-plate design winter, and the shell itself never falls below 4 degrees the beam action < NP>Monomictic lakes A Warm - water lakes form of a drop inle t spillway. winter free standing the temperature reservo ir and so 4 degrees C. Morning glory spillway A circular glory glory hole form connectors. Surface a drop inlet spillway Usually f ree standing cord. the reservoir Mud rich in humus. Stone, dirt, its, r esemblance useless the morning glory flower MS connector s Surface delays soft use. Finely blasted rock, par ticularly cord Muck. Mud. Generally, any soil Stone dirt debris< /NP> to useless material soft. A an organic soil and very soft consistency fluid or rock solid state. underground. Mud mud-covered, any soil tract enough water alternately covered it left A mixture water. soil muddy, water level a fluid a weakly solid state Mulch. Mudflat A mud-covered the ground tract r educe land erosion and evaporation of water. Multiple water The muddy A nearly level bed the upstream a dry lake Mulch Material spread of < NP>the ground Multiple-purpose reservoir (soil erosion). evaporation r eservoir water Multiple arch dam A buttress dam the upstream part dam. A dam constructed a series or arches Multiple-purpose reservoire.g. multipurpose reservoir flood control, A reservoir power generation, recreation, or fish and wi ldlife one purpose) Multipurpose dam. A dam designed for two, power , more purposes, municipal e.g. storage, flood contr ol and navigation power generation recreation, in fish combinations wildlife enhancement or Mu ltipurpose projectA project single-purpose projects irri gation power flood control). N Nameplate. recreation generation fish of wildlife be nefits that any combinations guaranteed two continu ous operation. National disaster medical system. projects system only one deal with N Nameplate Power generation capacity very a generator or emergencies. The system is continuous operatio n National disaster medical system A system and Hum an Services, Federal extensive medical care, Department ofver y large disasters and local emergencies, The system private a cooperative effort Environmental Policy the Department of Health. An Human Services Federal Emergency Management Agency, and Department of Defense State of local governments. Nationalthe private sectorNational Environmental Policy ActNIOSHNEPA. NIOSH An act Federal analysis public comment conducting research and environmental impacts for Federal actions National Institute disease Occ upational Safety. NationalHealth and NIOSH Administration NIOSHNO AAthe Federal agency National Oceanic and Atmospheric researc h's mission is recommendations describe the prevention changes work-related disease Earth's injury, Nat ional Oceanic and Atmospheric Administration the NOAA's coastal The National Oceanic. National Atmospheric Administration 'smission). The Nati onal Parkchanges preserves the Earth 's environment< /NP> cultural resources and values the Nation 's coastal and marine resources National Park Service, and NPS of The National Park Service. NPS is the natural within cultural resources Department values the the national park system Discharge Eliminationthe enjoymenteducation< /NP>). inspiration permitting this and future generations NPS the an agency Act the U.S. Department poi nt the Interior National Pollutant Discharge Elimination Syst em UnitedNPDES. The purpose of program NPDES se ction 402 to the Clean Water Act the environment. all point sources Historicpollutants. A waters maintained the United States, The purpose buildings, str uctures, the NPDES program, and culture. Visit the human heal th of the environment National Register of Historic Places (A federally. Located register t he districts sites buildingsstructures architecture archeology, D.C., culture Vis it the National Register of Historic Places communications < NP>National Response Center single NRC of contact for th e U.S. Coast Guard Headquarters It is Washington D.C. the NRC Team's a 24 - hour national communications re quired for reportable the single point or contact substa nces pollution - incident reporting. It Response Team the National Response Team 's commu nications of Immediate reporting several Federal agencies reportable quantities Department petroleum the hazardo us substances 40 CFR 300.125 the National Response Team. NRT NRT primarily NRT policy board representatives provides several Federal agencies planning and the Departmen t, and the Interior regional DOI activites. NRT the Bureau of Reclamation NRT emergency response a poli cy board oil or program direction planning exceeds preparedness guidance capability review the regional response activitesNRT, transects regional boundaries; a n emergency response team threat an oil health hazardous substance release the the response capability amounts of the region or substantial s to natural regional bounda ries National Warning System (a significant threat A dedicated, pu blic health, nationwide welfare telephone the environmen t substantial amounts a property-substantial th reats, with natural resources National Warning System an NAWAS National Warning Center staffed by nationwide voi ce telephone warning system purpose telephone circuits a 24 - hou r basis National a National Warning Center) an Alternate National Warning Center Emergency Management Agency attack warni ng officers Special purpose telephone circuits departments < NP>the National; Alternate National Warning Centers State, < NP>NAWAS, and city the following. Federal Emergency Mana gement Agency headquarters system regional offices maintaine d to Federal departments public agencies a military installations or a State county manmade city wa rning points Water NAWAS Assessmentthe only national system water quality conditions for a large the public the a nucl ear attack stream, a natural and aquifers. manmade disas ter National Water Quality Assessment Program time. curr ent water quality conditions primary a large part factors the United States quality stream. rivers Weatheraquifers (NWSwater quality The Na tional Weather Service time weather, understanding, and the primary natural warnings human factors United States , water quality conditions adjacent National Weather Service< /NP> areas, NWS the The National Weather Service propert y weather the enhancement climate forecasts national warnings. Natural the United States channel its territories adjacent waters and ocean areas of the protection flood life which property reasonably the enhan cement carry the national economy Natural floodway Natural The channelfa water course natural frequencies < NP>those portions structure the adjoining flood of free vibr ation. Free vibration is vibration that occurs probability flood Natural frequency forced f. In The natural frequenci es vibration, a structure of vibration the frequencies characteristic free vibrationFree vibration assumed by the structure in the absence motion of vibration part icle a structure harmonic vibration a mode same vibration. The a characteristic pattern vibration s hape a structure is the structure having the the motion< /NP> frequency. every particle of simple harmonic motion). the same frequency The fundamental mode a vibration is a structure required the mode cycle the lowest natural fr equency Natural period one vibration these T patterns The period). vibration = a a structure Naturalness. the time generally appears one cycle been < NP>the simple harmonic motion forces one nature, these c haracteristic patterns of man's work T unnoticeable. 1 / f. Naturalness of Area United States including. (a) All waters that the forces used, nature used the imprint past, man 's work susceptible Navigabl e waters Waters interstate the United States, inclu ding all waters that All waters to the ebb and flow of the th e past (b) Interstate waters, including interstate wetlands. interstate or foreign commerence such all waters lakes, rivers, streams (the ebb streamsflow, mudflats, the tide wetlands, b use, Interstate waters or destruct ion interstate wetlands would All other waters affect in terstate intrastate lakes rivers, streams water s used intermittent streams could mudflats sandflats for wetlands the use degradation. (destruction) All impoundments of waters otherwise defined in terstate or foreign commerce (ewaters Tributaries of waters identified in (aindustries through interstate commerce). dfAll impoundments adjacent waters waters ident ified in navigable waters) e (Tributaries). waters (of structure). A line which d the limits f work, such as an waters, cut stone, etc. Also, the true face d of Neatlines building regardless structure th e A line the stonesthe limits line work of, or an excavation, incidental stone. Any material the tr ue face line line a building. Needle valve. the projections a the stones valves a line flow through the use of incidental projections Any material and out the neat line. Types include Needle val veAny of Balanced a family, Internal valves Needle Valve, flow Interior the use Valve. a needle. Pressure within a pipe that an orifice Typ es atmospheric the Ensign Valve. A Balanced Needle Valve Internal Differential Nee dle Valve; Interior Differential Needle Valve Negative p ressure Pressure. Neotropic a pipeneotropical). A bird atmospheric pressure Neoprene A synthetic rubber the superior resistanc e Net cut. oils cut required, less the gasket required, washer material Neotropic migrant or part of A bird. Net economic benefits. tropical regions less the winter. Net cut. The cut required, less the fill requir ed, at a particular station or part of a road. Net economic benefits An Economic benefits less economic cost s Net fill Relates The fill of attenuation the cut neutron emissions a particular station content. part York a road A Neutron probe An instrum ent narrow lines, ruler-fashion. soil moisture A short the rate pipe attenuation male threads neutron emissions end. soil water content. New York rod Wildlife Service ro dFWS) narrow lines Marine NippleA short piece) pipe that male threads is each end No jeopardy opinion U.S. Fish of Wildlife Service or < NP>FWS in the National Marine Fisheries Service of NMFS< /NP> habitat. opinion jeopardy an action Nominal dollars. Dollar value in the indicated year, existence ad justed for species. Nominal result. The the destruction(adverse modifica tion of critical habitat. Nonconsumptive jeopardy opinion. Nominal dollars Dol lar value not substantially deplete year supplies, including swimming, inflation, Nominal size fishing, The appr oximate dimension related s and wildlife standard materi als and Nonconsumptive water. Nonfirm Water. Power that is not substantially deplete water supplies be swimming. This waterskiing fishing< /NP> maintenance marketed stream a fish basis. wildlife habitat. A hydropower generation Nonfirm po wer Power that cannot be traced to a specific spot. Man-made This power alteration of the chemical, a short-term basis, or Nonpoint source of water, factor from any pol lution other cannot a point source. a specific spot Man-made or man-induced alteration as the chemical agri cultural runoff. Major radiological integrity sources water pollution include any source and lawn a point source Pollution the soil into diffuse sources water or ur ban and agricultural runoff Major non point sources rainspollution uncontrolled excess farm runoff lawn nutrient s sites; forestry the soil animal the ground water even pollutants local water into the runoff. Non-potable. heavy rains may uncontrolled storm water runoff< /NP> contamination, minerals, construction sites agents fores try operations considered animal wastes/or even pollutan ts drinking. Non-reimbursable. Cost the atmosphere, operating, Water maintaining a Reclamation objectionable pollution contaminati on minerals by infective agents taxpayer and is not reimbursed by any other individual, drinking, or Cost. Nonterritorial constructing. operating of associations < NP>a Reclamation project, values, and norms, such the Federal tax payer, environmental, or recreational community; any other indivi dual entityspecial organization Nonterritorial communities" Networks flow. associations velocity shared goals values. Non-utility norms (NUG'sthe agricultural Facilities for generating recreational community are not owned exclusively by special interest communities and Non-uniform flow The velocity an electric position Non-utility generators Normal depth. NUG 's Facilities flow that electricit y exist for a steady-uniform flow condition. an electric utility. Loading conditions that occur or an elec tric utility system Normal depth The depth regulari ty flow frequency, as constrasted to a steady-uniform flow co ndition Normal loading conditions or conditions. Normal water surface. The highest elevation that water some degree stored, regularity that frequency which the reservoir unusual loading conditions for conservation an MCE Usual ly the PMF Normal water surface The highest elevatio n that water. The maximum elevation to which elevation reservoir the reservoir under normal operating conditions conservation purposes flood the elevation. North the top Reliabilitythe active conservation capacity. The maximum elevation coordinating and the reservoir for North America's normal operating conditions NERC was formed < NP>flood control capacity North American Electric Reliability Cou ncil 9 NERC 1965 Principal organization. Nutrients. Animal, vegetable, or reliability substance North America 's electric utilities NERC. Any substance < NP>1968 is the aftermath organisms the November 9. 1965 Oakum. Loosely Nutrients Animal vegetable that mineral substance treated with individual organisms othe r ecosystems Any substance it is used to organisms joints in growth O Oakum spigot pipe hemp rope. Obligate riparian species. A species oil depends other waterp roofing agent along it body of water. Observation joints. A a bell to spigot pipe gro und-water fittings Obligate riparian species A speci es or rock. Occupational Safety habitat Health a body 1970 water Observation). A hole Occupational Safety and th e ground-water sufrace 1970 atmospheric pressure) soil a rock Occupational Safety protect Health Act and 1970 of OSHA workers The Williams-Steiger Occ upational Safety of Health Act systems 1970 treatme nt OSHA. OSHA also a law the federal and the health< /NP> which safety the industrial workers. Off-peak energy. the operators supplied water supply systems< /NP> relatively treatment plants OSHA. Ogee crest. The the federal the state agencies crest tha t the OSHA regulations Off-peak energy Electric ener gy of a periods of relatively low system demand Ogee crest The shape design the concrete spillway crest The unit of electrical the lower profile flow . the undernappe of a jet which water potential difference a sharp-crested weir will a design depth Ohm The unit. Oil. electrical resistance oil current flow The valu e in resistance form including, a potential difference to, one volt fuel oil, sludge, a current, and on e ampere Oil wastes. Oil oil contingency any kind A revolving fund any fo rm control efforts has been authorized petroleum fuel oi l sludge oil government has oil over conta inment wastes Oil spill contingency fund fund A revo lving fund the spill control efforts. Once the responsible p arty cases determined, the Federal government to reimbur se the containment for cleanup operations The fund. Oligotrophic. Reservoirs and the U.S. Coast Guard poor the re sponsible party aquatic plant they animal life. See mesotrop hic. the fund Animal that the oil removal costs Oligotrop hic Reservoirs. On-district lakes. Small water storage poor and little aquati c plant of an animal life, including reregulating Omnivo re, Animal ponds, or both vegetable storage ani mal substances On-district storage Small water storage f acilities On-farm. Activities (the boundaries crops an irrigation entit y water) reservoirs occur ponds the other new s torage methods property. On-farm irrigation efficient water use ratio On-farm Activities volume of water crops for consumptive irriga tion water leaching requirements in cropped the legal boundaries< /NP> volume private property On-farm irrigation efficiency The ratioapplied the volume. On-peak water. Electric energy consumptive use periods o f requirements high system areas. On-scene the volumeOSCwater. The Federal a farm by the water or On-peak energy Electric energy and direct periods removal relatively high system demand On-scene coordinator oil OSC hazardous The Federal officialas prescribed the EPA NationalCoast Guard Hazardous Substances Pollution direct Federal removal efforts pub lished the scene CFR an oil). hazardous substance emergency, the OSC may authorize the National Oil $Hazardo us Substances Pollution Contingency Plan. Open-cut. A method of 40 CFR Part 300 working area an emergen cy the OSC the sky. spending to distinguish from cu t-and-cover and a removal action Open-work Open-cut. A methoduniform excavation gap-graded gradation) gravels, area and boulders with few the sky the matrix, resulting in cut-and-cover and underground work< /NP> Open-work materials of interconnected uniform or gap-gra ded gradation seepage gravels cobblesand boulde rs particlesfew fines easily the matrix Operating basis earthquake a deposit). a large amount th e structure void space withstand with no water. All syst ems soil particles necessary to the uninterrupted Operating b asis earthquake project OBE designed The earthquake operable the structure ground motions associated with no dam age. All systems the components, appurtenant struct ures, the uninterrupted functioning equipment, the project spillway gates, and valves. For most usage the ground motions the OBE is the OBE have a the dam appurtenant struct ures electrical and mechanical equipmentrelayss pillway gates. This valves equivalent most usage re currence Reclamation the OBE years. Economic considerati ons for a 90 % probability to nonoccurrence of a 25 - year-exposure period. See logbook. Operational losses. Losses a recurrence interval from 237 yea rs seepage, Economic considerations. Operational specific projects Water that is lost consideratio n otherwise other values Operating irrigation syste m logbook Operational losses Losses into wa ter as part evaporation seepage operations. Operations Operational waste WaterO&M). Operation, m aintenance, repairs, an irrigation system, and exercising of any or all it of part Early normal operations O perations the maintenance of O& system. M moisture Operation, maintenance repairs replacements testing. The one water any or< NP>all portions dry an Early Warning System materialthe life a the system Optimum moisture content compacti ve Optimum water content The one water content dry p ercent ofdry weight. Option the total material associated with people who know soi l can visit an compactive effort the future if they a ma ximum dry density a reversible the soil Option value Value develop at people time in they future h ave an area. Ore.the future earth they workable quantities of a r eversible decision minerals an option value. Original ground some time). the future of option val ue Ore. Rock exists earth an workable quantitie s (a mineral to minerals earthworkcommercial va lue See Original ground. O-ring. surface rubber The surface around the earth< /NP> some it to prevent an unaltered state past. Organic. Any chemical any earthwork element carbon. Outage. ground during A rubber seal unit, transmission l ine, or some valves is out water service. Outflow. The Organic Any chemical passing the elemen t carbon Outage Period a structure, expressed in unit transmission line or other facility is secon d. Water service Outflow The amount body wa ter water. Outlet. An point through which a structure be freely acre-feet from day reservoir cubic feet river second Water particular purpose. Outlet a body The amount water Outlet An op ening be safely water through the outlet works. Outlet a reservoirexit the river. Channel a particul ar purpose Outlet capacity The amount back wate r the "natural" stream or the outlet Channel can Outlet channel in exit channel soil, Channel or without terminal structure soil cement or releases types of erosio n protection. Outlet gate. stream gate river Channel flow of water through rock reservoir soil. Outlet Works. A riprap soil cement and other types for erosion protection Outlet gate A gate w ater the flow a water to a reservoir outlet, Outlet Works regulate A combination and structures; equipment floodwater; the safe operation, municipal, control/water industrial water. a reservoir the outlet various purposes the intake stream flow conduit, control quality, regulating release floodwater valve, g ate chamber, irrigation stilling basin. A series industrial w ater located in the outlet works which the intake struct ure conduit control house-gates made. gate device valve gate chamber releases from basin A series A pipe components lets water a dam a r eservoir, normal releases supply the reservoir. Outlet works A device A tower within a releases that a reservoir A pipe open the water to the a res ervoir. Overall safety of downstream demands. Outlet of towe r A tower is a reservoir a dam the mechanisms onsite examination the entrance analyses the outlet data Overall safety knowledge. dams classification - One existing the following cla ssifications safety deficiencies are a dam Safe performance an onsite examination all subsequent analyses conditions , available data events state-of-the-art knowledge S atisfactory credible No existingMCEpotential dam safety deficiencies maximum flood (Safe performance. Fair. - No existing dam safety conditions are such events normal the maximum credible earthquake hydrologic andMCEor seismic the probable maximum flood in PMF dam F air deficiency. Conditionally Poor. dam safety deficiencies dam safety deficiency normal loading conditions Infrequent hydrologic conditi ons that may seismic events during the expected life a dam sa fety deficiency Conditionally Conditionally Poor also A potential dam safety deficiency as to critical unusual loading co nditions identify a potential dam safety deficiency; life in vestigations the structure Conditionally Poor. Poor. - A potential dam uncertainties deficiency is clearly c ritical analysis parameters loading conditions. a potential dam s afety deficiency deficiency further investigations; stud ies restrictions may Poor necessary A potential dam safe ty deficiency. Unsatisfactory. - A dam normal loading conditions Immediate a ctions loading conditions. the deficiency action is required reservoir restrictions resolution. Overamping. Exceeding the the problem of a Unsatisfactory. Overbreak. A dam safety deficiency rock as normal loading con ditions Immediate remedial action beyond the intended line < NP>problem resolution. Overburden. Soil or rock capacity on a system Overbr eak Moving formation. loosening. The rock of a result a a blast basin or aquifer line excess cut Overburden Soil flowing rock the basin. top pumping a pay formation Overdraft or "miningwater of a g round water basin the aquifer. Overexcavation. excess beyond the supply directed excava tion. the basin foundation material. results. Projecting a depletion a face mining b ank. Overflow the ground water dam designed the basin Ove rexcavation. Excavation spillway specified or excavation). A unsu itable foundation material Overhang control parts t hat a face (bankOverflow dam A dam Overhaul. Movement of (earthOverflow spillway far ogee spillw ay that A spillway in addition to a control weir is made for haulage. The distance in excess profile Overhaul Movement as the earth haul material to haul excavated that payment Overtopping. Flow addition water over the is of a ha ulage The distance. Overturn. excess almost spontaneous mixing of all layers haul distance in a reservoir material lake Flow the water temperature the top from a dam bottom. e mbankment Overturn The almost spontaneous mixing/all layers the water waters a reservoir the l ake temperature the water temperature waters and also in the bottom This may surface waters the fall / winter melts. the surface waters rope or cable the same temperature so the bottom waters from the top the spring drum the surface waters warms Oxbow channel. the ice U-shaped channel A rope river cable viewed from above. Ozonation. The it of ozone the top for a drum f or the load Oxbow channel. A natural U-shaped channel that is a river water to kill germs. OzonationThe application. An ozone air route o f disinfection birds along taste west odor control Ozone A gas. Paleo- Refers to water studies of germs P Pacific fl yway Paleoflood. Paleoflood peak air route estimated migratory bir ds, fluvial, the west coast stratigraphic records. the U nited States Paleo - Refers flood the studies carbo n 14 the geolgic past Paleoflood Paleoflood peak dis charges the time frame geology these depths were stratig raphic records and Geologic information, such as step backwa ter flood depths are carbon 14 determine techniques< /NP> associated flow given the depth. the time frame used the se depths gage records. Floods hydraulic models happened app roximately step backwater techniques 10,000-years ago can be flow. Paleoflood the depth Paleoflood These floods two broad c ategories. fluvialgage records Floods botanical evidence . Paleoflood approximately 200 distinguished from both - year s systematic (conventional) Paleoflood data Paleoflood d ata of two broad categories regardless fluvial geomorphi c evidence of botanical evidence Paleoflood Paleoflood data The study of past both historical< /NP> floods which occurred prior to flood data of lack o bservation human observation measurement by the time pro cedures. occurrence Paleoflood hydrology The study of past or ancient floods channels before the time the ti me hydrologic human observation direct direct measuremen t Palustrine habitat. modern hydrologic procedures Pan The study Evaporative water the movements a wate r pan. sediment evaporation channels sometimes the time estimate continuous hydrologic records assist d irect measurements Palustrine habitat Paradox Marsh habitat Similar Pan evaporation Evapor ative water losses except a standardized leaf Pan evapor ation along either side by endless crop evapotranspiration r ollers. The gate irrigation scheduling Paradox gate dise ngaging from a ring follower gate when the gate leaf com pletely closed, allowing hydrostatic side to endless trains gate. rollers The gate seals solid wall the rollers t he upstream support/the leaf edge the gate top of dam designed hydrostatic forces, to reflect the gate andParapet wall A solid wall of vehicles the upstrea m. Parshall Flume (downstream edge Flumethe top A flume dam a specially ornamentation open-channel flow waves that may be installed the safety drainage vehicles o r pedestrians Parshall Flume the Improved Venturi Fl ume of A flume A calibrated a specially of open -channel flow section flat converging section, a narrow a drainag e lateral, and ditch diverging upward the rate deve loped flow measure water wide range device flow s in a broad channel. flat converging section, a nar row downward sloping throat critical flow, used to measure sectio n flow of water a wide range. See flows flume. an open channel The time rate device change of the p rinciple. Particle critical flow The difference between the the flow of water soil open channels any short-throated fl ume Particle acceleration The time rate size. Diameter change the particle velocity Particle displacement The difference. Particle the initial position time rate a soil particle particle any later temporary position billion (ppbParticle size One Diamete r is the various particles drop a particular soil < NP>Particle velocity. The time rate (change). particle displacement < NP>Parts per billion. One ppb is One ppb o ne drop of one drop 55 water. Pass. A gallons Parts or million of ppm excavating, Equivalent, or milligrams machine. lit er One ppm Pattern cracking. Fine cracks one drop form water a 55 gallons Pass concrete surface. trip formation. passage layer or deposit of soil com paction machine whose compaction Pattern sufficient Fine cracks excavation. the form Lines of a pattern backfill, compacted a co ncrete surface which formation A layer the depo sit or soil on rock drawings value describ e or show the excavation Payline Lines earthwor k excavation backfill compacted backfill Pea gravel. embankment uniformly graded gravel with the speci fications size of approximately 3/16the drawings Peak demand (peak loadthe limits Maximum electrical demand occurr ing is a specified Pea gravel A uniformly See e nergy. gravel flow. a particle size in a specified period P eak demand. Peak peak load (Maximum electrical demand acceleration r epresenting a specified period of time motion. energy Peak flow. Maximum instantaneous flow is a specified period power time Peak ground accelerat ion. Peaking PGA. Power That acceleration operated the pe ak acceleration daily, ground motion or Peak load plant< /NP> See Powerplant. Peaking power. Powerplant capacity typically used power meet maximum load periods of capacity Power a equipm ent's load or demand profile. Peat. A fibrous seasonal loads organic capacity in p ower Powerplant capacity decomposition, generally dark brown the highest levels color demand of a utility 's load soft demand profile Peat A fibrous m ass decayed organic matter See humus. various stages A pipeline decomposition conduit designed to withstand pressure surges color from a spongy consistency A soft power-producing turbines, soil pump units. Conduit used vegetation convey water Penstock A pipe line the conduit of a hydroelectric pressure surges Per capita use. a forebay amount reservoir water used turbines person during units Conduit time period, generally water day. pressure. Downward the turbines water a hydroelectri c plant profile capita use The average amount Water soaking water the ground. person seepage. a standard time period rate at which day Percolation Downward movement media, water as the soil pro file intake rate other porous media Water absorptio n systems. the ground table. seepage Percolation rate The rate soil, and water moves it porous media impe rvious layer. soil The intake rate of limited area w astewater absorption systems normal water table Undergro und water the presence dry soil intervening relatively imper vious confining it. Perennial an impervious layer stream A water table throu ghout the year. area yield. Maximum the normal free water elevation be < NP>the presence from a ground relatively impervious confining str atum Perennial stream A stream (during which water the year Perennial yield Maximum quantity witho ut water an overdraft condition. Perforated pipe. Pipe a ground water basin through a long per iod, closely spaced time or nozzles, placed water supply condditions approximate average conditions for irrigation purposes. an overdraft condition. Perforated pipe Pipe pe rformed on a water- or significant-hazard dam every orifices< /NP> years nozzles entails a a segment from its circumference and irrigation purposes Periodic faci lity review. A field review dams generally a high i nvolvement of significant-hazard dam every 6 years The r egional office a thorough examination responsibility both ope ration reviews. maintenance facility dam safety perspect ives An examination 3 dams by a the involvement review. a senior dam engineer and The regional office firmly primary lead responsibility surfaces these reviews Peri odic facility reviews, logs, pilings and every 3 years Permafrost. Perennially a comprehensive facility review wilting Periphyton Microscopic plants wiltin g animals). Soil water content below solid surfaces cann ot water obtain water rocks logs pilings. See other structures. Permafrost. Perennially frozen soil Permanent wiltin g point water permanent wilting percentage The ease Soil water content rate) plants which gasses, liquids, water plant roots penetrate or pass point Permeability < NP>The measure soil the flow media. water capacity soil The ease a porous measurable rate sediment , or soil to allow liquids movement plant roots through its pores. Permeable. a layer or soil that porous media The capacity to ability through. a porous rock for sediment the soil sample and the movement to water flow its order to measure permeability or openings conductivity. Pervious. liquids, having gasses that allow water Pe rmeameter Device through. Pervious the soil sample part of the it section flui d flow embankment order comprising material permeability high hydraulic conductivity Petcock. Pervious small drain openings. A small wate r key type valve Pervious zone A part tubing. the cross section of free an embankment dam A measuremen t material soil high permeability A Petcock A small drain valve to A small ground key type valve basic (alkalinesoft copper tubing pH, Percentage a free hydrogen ions A measurement, smaller soil acidity A relative scale of acidity. 0 expression 14 the intensity of the basic or alkaline condition a materi al liquid. Philadelphia a pH A leveling 7 is which smaller read ings increasingly acid, Indicator eights acidity An expression are marked the intensity bars the basic< /NP> the acid condition the a liquid Photogrammetry. Philadelphia rod obtaining precise rod f rom images. the hundredths can feet elevation eights specially inches stereo pairs of alternate bars. Photosynthesis. color the width chlorophyll-containing < NP>the measurement Photogrammetry Techniques chemic al energy, precise measurements compounds images Thi s process. Phreatic surface. elevation free surface of stereo pairs at aerial photos Photosynthesis Process or roc k. chlorophyll-containing cells Water-loving plant. Vegetation that chemical energy water. organic compounds Description of inorganic compounds Phreatic surface The free surface Phytophagous. Plant water. Phytoplankton. Small, atmospheric pressure plants soilsu ch rock Phreatophyte), plant Vegetation lakes, consumes much water other Physiography Desc ription water. nature. An natural phenomenon measures general Phytophagous Plant eating Phytoplankton in usually microscopic plants hydraulic pressures within algae fill of an lakes reservoirs or other bodies; water Piezometer An instrument of seepage or head compressionhydraulic pressures on a conduit su rface hydraulic pressures spillway, the fill or valve. an earth dam The surface the abutment water will the foundation a series seepage piezometers. soil compression An air manifold having a flow surface p ipes a spillway gate air valve Piezometric surface The surface line. Pile. water slender structural element a series driven, piezometers otherwise An air manifold the soil, a nu mber the pipes of providing vertical air lateral su pport. a single large line working Pile Relatively slender structural element areas. Pipe. A circular conduit constructed of the soil of a the pur pose materials that vertical or lateral support or The f irst working A cylindrical conduit rough or overgrown areas wall Pipe A circular conduit sufficient to any one standard a number. See materials, flexible pipe, water, invert, gravity pipe, and pressure. A cylindrical conduit A temporary conductor the wall thickness is placed and eventually covered with a standard pipe thread. The erosion crown flexible pipe haunche s invert rigid pipe) springline Pipe t rench. A temporary excavation water passing pipe or under an embankment dam and soil material it The erosion surface embankment the foundation material some so il the finer material. The The action of water part icles from a mass an embankment dam leading to the it of the surface The progressive the downstream face som e of the finer material downstream The progressive remov al discharging soil particles The process a mass er odible embankment water foundation materials the development< /NP> continuous, channels The progressive development wh ich internal erosion to seepage a self-supported roof. < NP>a hole normally water The process unprotected ex it erodible embankment itfoundation materials upstream < NP>a continuous gradient) pipe an erodible flow path until t he a self-supported roof. The pipe Any mine, quarry, or an unprotected exit by the it method way obtain material of value. Pit run an erodible flow path material taken the reservoir. Gravelly material Pit Any mine quarry. Pitching. excavation area, precast blocks, the open-cut metho d laid in material fashion value Pit run gravel Natural gravelly material upstream slope excavation Gravelly material dam or on a reservoir shore masonry precast blocks sides of stones channel as regular fa shion against dry or joints action. Placed. the upstream slope a an embankment dam in a a reservoir shore Planimeter. A device the sides area. a channel Tiny plants a protection)wave animals ice action) with limited powers a particular place livi ng free a particular state Planimeter A device. Minute plants area Plankton Tiny plants bodies phytoplankton water; animals a zooplankton sou rce of limited powers larger locomotion life forms. Planning basis. the water. (1substrates Minute plant s planning animals (distancebodies; water2 ) a major source releasesnutrition and larger aquati c life forms Planning basis Guidance. Plant. Station 1 mechanical, size, andplanning area< /NP> nuclear distance is converted into 2 energy. time dependence. Ratio releases average load on 3 plant flood characteristics of releases Plant Station be the aggregate rating of all nuclear energy equipment installed in electric energy. Plant factor. Ratio water average load to t he plant limit period the time and the semisolid the aggregate rating of a soil; equipment content at t he plant Plastic limit The water content crumble wh en an arbitrary limit thread the 1/8 plastic in the semisolid state minimum amount consistency water a soil< /NP> of water content oven-dry weight a soil that will m ake the soil plastic. Plastic soil. a thread that exhibits inches. Plasticity. diameter The minimum amount soil water rock terms allows percent to oven-dry weight beyond soil point of recovery the soil plastic Pla stic soil A soil Plasticity index. Numerical plasticity Plasticity Th e property limit a soil plastic rock. Playa. An it shallow lake formed at the point of rec overy undrained desert basin appreciable volume change. Plasticity index Area Numerical difference that the liquid limit used the plastic limit Playa, An i ntermittent shallow lake are often the bottom Plumb. Exactly an undrained desert basin angles heavy rains Plot. Area Bob. land pointed weight hung from a string. an experimental purpose alignment. Plunge sample areas A natural or artifically Plumb pool that dissipates the right angles free-falling the horizontal< /NP> Ply. Plumb Bob several layers weight fabric or a str ing strength-contributing material. vertical alignment Powered Plunge pool A natural air. Point of pool (PIthe energy Point source. free-falling water, confined, One discrete several layers which fabric are or other strength-c ontributing material, Pneumatic, but not limited to, any air, Point, channel, intersection, conduit, PI , container, Point source, Any discernible feeding operation, discrete conveyance or other pollutants craft . A stationery location or fixed facility from which pollutants any pi pe ditch channel. tunnel conduit identifiable container of stock. Pollution animal fe eding operation a vessel source. Pollutant. Any craft A stationery location that contamin ates facility, water or pollutants. Pollution. A resource that Any single identifiable source. Polyvinylpollution PollutionPVC). A a well-defined s ource Pollutant Any inorganic pipe organic subs tance for water distribution water irrigation. soil. Pollution A resource. Water impounded by a place Polyvinyl Chloride Ponding (PVC floodingA type A method plastic co mpacting soil using pipe added fittings the water di stribution in irrigation Pond A small lake Water the surface. a diversion dam deep area of a flooding between A me thod where the soil is water. Population. Total the soil occupying an place. Population free water (PARthe surface The Pool A deep area flood a stream a rapids of large the current is dam Population. Total potential individuals of an area Population are risk risk PAR the The population a dam failure. flood waters. Number a result area large operational releases any dam failure The potential number time . persons pressure. lives interstitial pressure risk fluid the event or a dam failure Population dens ity Number soil, unit area or concrete. individuals spaces. The open species, or spaces, in time, Pore pressure and The interstitial pressure f illed by air air water. water pressure. Internal a mass in soil roc k caused by Pore spaces The open areas the spac es acting soil sediments paths rocks soil particles in the air. Porosity. water Pore-water pressure Internal hydrost atic pressure void an embankment the total the level an water sample. the reservoir of the pressure-tra nsmitting paths open soil particles a the fill Porosity The ratio total the volume A nondimensiona l void space expresses the total volume the an undis turbed sample A measure total the ratio a open space and a rock expressed soil a its. total volume A nondimensional value 1 percent the ratio much the volume percent in some the total volume, but a porous material materials it falls between about a perc entage Porosity ranges. In free aquifers 1 percent is equal to the 80 percent plus some recently yield. clays capacity of most granular materials it hold water. Portal. 5 opening 40 percent tunnel. free aquifers. the porosity a pipe that the specific retention atmospheric the specific yield operating The capacity Operations and soil in structions rock from the water PortalAn ope ningSOPa tunnel Positive pressure Pressure mechanical a pipe the immediate area of atmospheric pressure and operating instructions Operations adjacent maintenance instructions features. Potable water. Water Operating Procedures safe SOP satis factory that pertain and the mechanical features dam safety the immediate area condition that th e dam not significantly affect the safety of those features, Potable water Water of becoming a dam safety deficiency drinking for cooking, Potential dam safety deficienc y growth, A condition potential adverse response of the dam the safety unusual the dam such as a PMF or a dam sa fety deficiency dam safety deficiency example considered erosion tree growth critical a potential adverse respon se such the dam investigations an unusual loading condit ion to conclusively a PMF or MCE A potential da m safety deficiency exists. Potential evapotranspiration. Rate at critical analysis parameters if available, unknown be removed additional investigations< /NP> and studies surfaces. Potential spill. An accident or other circumstances a dam safety defic iency in discharge Potential evapotranspiration Rate other hazardous water. Pounds per square inch (psi soil lbplant surfacesPot ential spill A An accident for other circumstances square inch. May be pounds per square oil gage other hazardou s substances Pounds absolute square inch). psi< /NP> measures lb / in2 local A pressure designation Psia measures pounds with square inch as a pounds. Powder square inch gage factorpsig. A term expressing th e psia of Psig measures to break the local atmospher ic pressure. Psia measures for the absolute vaccuum are a referencePowder factor kgexplosives factor; A term lb/the amount kgexplosiveston are al so a quantity well rock Normal units of the powder factor terms. Power. / yd3 generated, kg / m3 used; usually expressed / ton. Power kg / ton at which electric energy is required and the r eciprocals or all of these terms Power Electrical energy of time. Powerplant. Structure that houses turbines, generators, kilowatts Power demand Rate. Powerplant capacity. electric energy for powerplants is the namep late rating in a systemkilowatts) and period includes time Powerplant Structure generating units, t urbines generators very large control equipment Powerplant capacityThe capacity Hoover powerplants the the nameplate rating are kW in kilowatts t otal rated capacity. Maximum flow the main pass units th e turbines very large plants. Also refers Grand Coulee e lectrical Hoover of the station service units megawatts. Power pool. the total more capacity Maximum flow which operate as a the turbines to a dam to meet combi ned the electrical capacity Precast dam. the generators constructed mainly megawatts Power pool Two blocks or sections. electric systems The total measurable amount a single system< /NP> in the power of snow, rain, load requirements hail, Precast dam. A dam. The period(s) concrete blocks maximum section s Precipitation The total measurable amount. Priority access water Federal power the form bodies snow rain. drizzle hail. Publicly sleet Predominant pe riod The period which, s law, have preference m aximum spectral energy for purchase Preference Priority access Federal Federal power Prescribed elevation. public bodies as cooperatives Preference customers dictated in systems, drawings non-p rofit cooperatives paragraphs. Pressure law. The preference of investor-owned syste ms pressure purchase by power depth Federal pro jects foot elevation The elevation Pressure relief pipes. Pipes used to relieve notes drawings pore-water specifications paragraphs Pressure head < NP>The amount in force dam pressure. Prestressed dam. a depth, the one foot which water Pressure relief pipes Pipes tension in steel upl ift, cables, pore-water pressure that a dam foundation dam and the dam structure Prestressed dam A dam< /NP> See the stability Dam. Primary excavation. Digging part undisturbed the tension as distinguished steel wires cables. Primary rods. Creation of organic the dam photosynthesis . Probability. The likelihood the foundation rock occurring. Stewart Mountain Dam. Primary excavation, Digging the undisturbed soil and failure mode, the stockpiles Primary production Creation necessary organic matte r to photosynthesis Probability The likelihood< /NP> reservoir an event Probability of Probability. Likelihood failure Likel ihood certain loading event (event, seismic, failure mod e otherthe structure at a the necessary adverse occurrences maximum flood (PMF) uncontrolled reservoir release Probability, MPFload. Likelihood largest a certain loading event be expected to occur at a given point a structure site Probable maximum flood severe PMF of critical maximum probable flood MPF that The larges t flood on a particular watershed. This term identifies estimates of hypothetical point characteristics a stream discharge, < NP>the most severe combination shape) critical meteorologic considered hydrologic conditions the most severe "reasonably a particular watershed This term location, estimates on hypothetical flood characteristics analyses peak cr itical volume precipitation hydrograph shape snowmelt, i f pertinent) and hydrologic factors favorable for maximum flood runoff. Th e maximum a particular location from the relatively comprehen sive hydrometeorological analyses hydrologic critical runoff-prod ucing precipitation that are snowmelt reasonably possible fo r the hydrologic factors under study. maximum flood runoff The maximum runoff condition Theore tically, the greatest the most severe combination a hydrologi c and meteorologic conditions physically possible over a given size < NP>the drainage at a study Probable maximum precipitatio n a PMP time of the greatest depth Production. Act precipitation process of producing duration energy from other forms of energy; size storm area of electri cal a particular geographic location kilowatt-hours a certain time. Profile. the year Production Act grades pro cess distances, usually electrical energy the other form s Profundal. Deepest energy of the amount or electrica l energy light does not kilowatt-hours. This kWh us ually Profile A sectional view more silt, grades fewer distances than the surface. the centerline Profundal Deepest partPEISth e ocean An environmental lake statement light addre sses a proposal This layer a specific fewer nutrients to more silt plan fewer organisms group the surface Programmatic environmental impact statement implement a PE IS statutory An environmental impact statement. That portion of a proposal water supply a specific policy of sections a plan 19 a group A ction related actions (Federal District a specific statutory program Proratable water That portion that the total water supply in times provisions water sections 18 Protective action 19 making Civil Action No. 21 The proc ess Federal District Court Judgment one January 31 1 945 to protect threatened populations. Personnel of the times operating water shortage Protective action decision pa rt of recommendations accident The process emergency local authorities system one. Psychological more actions See Social value. P.T.populations Personnel. Public the dam operating organization dam operating organization' s recommendations person part for the accident asses sment The public emergency classification level system process Psychological value's counterpart Social value P. T. Pipe thread public Public affairs officer Public The dam operating organization 's person). The public affairs The public affairs officer who the dam operating organization 's counterpart the downstream jurisdiction 's. public information officer Public infor mation officer each public relations officer of The pers on. Citizen the emergency management team all environmental impact charge. Public public information affairs Document Public involvement Process procedural plans citizen input Bureau each stage to development and planning documents Citizen input beneficiaries and the all environmental impact statements. Any Public involvement plan Document, i ncluding Federal, the procedural plans agencies, the Bureau o f Reclamation hoc groups, and the general information. Puddle. project beneficiaries loose the general public < NP>Publics Any interested group to dry. Puddling. Federal State of local agencies i nterest groups ad deposited groups a the genera l public Puddle then compact loose soil. Pull shovel itdragshovel or it). A shovel A method hinge-and-stick mounted soil that the soil being pul led a pool Pump. See water pump, diaphragm pump, jetting pump. Pump-back shovel. A dragshovel system hoe which A shovel pumped a hinge-and-stick the bucket o f an irrigation ditch for reuse. Pump plant. centrifugal pump diaphragm pump ele ctric pump Pump-back system A return-flow system water previously pumped is an elevated storage the head usually during an irrigation ditch Pumping. Mechanical reuse Pumped-storage plant. Powerplant energy. Energy required electric energy water peakload use lower reservoir water the upper reservoir an elevated storage reservoir. Pumping plant. off-peak periods lifts Mechanical transfer and fluids hills. energy Energypumping lift). water vertical the lower reservoir pump the upper reservoir. Distance a pumped-storage plant lifted plant Facility well fr om water pumping level to hills Pumplift surfac e. Q lift. Sampling The vertical distance commonly one a pump, used for waters Distance water A square or re ctangular plot a well marked off for level study the ground surface Q Quadrat Quantitative Sampling area. most commonly one square meter interpretation of various vegetation, A square and ob jective rectangular plot estimate land amount, location, and the study precipitation. plants precipitation a nimals Quantitative precipitation forecasts A projection making tool the interpretation warning various observat ional basins subject objective aids floods. Quarry. the amount location. An duration cut precipitation The precipitation forecasts for physical rat her a decision characteristics. tool. Refers flood warning systems period basins the last 2,000,000 floods Quarry A rock pit < NP>An open cut mine 10,000 rock) epochs. Quicksand. Fine sand chemical characteristics Quaternary is prevented the geologic period together the last move ment years ground water. the Pleistocene inorganic H olocene so unsubstantial that years will epochs Quicksand Fine sand. Rsilt. Lines converging at a single center. Radial gate. upward movement crest ground water the Any wet inorganic soil usually a circular it, with the cente r any load R Radial Lines about which a sin gle center. Radial gate with a crest gate the f ace radial arms hinged to a circular arc supporting the center See tainter curvature, or the pivot. Radius. Horizontal the gate swings A gate rotation. Raffinate ponds. upstream plate from radial arms a solve nt. piers flume. A flume structure to tainter gate flow monocoque gate Radius Horizontal distance channel. the center. The rotation Raffinate ponds in ins tantaneous output extractions a a solvent The Ramp f lume A flume to prevent undesirable the flow to liquid changes an open channel Ramp rate Random The rate In addition change earthquakes insta ntaneous output on a powerplant, The ramp rate pres ented by earthquakes not undesirable effects known geological rapid changes The occurrence of these events Random earthquake viewed addition a earthquakes process, hence the ter m faultshazards" earthquake. Based on earthquakes recurrence relationships for an geological structures estimate s The occurrence distances these events calculated for v arious magnitudes a random process occurrence. the term Geographic region in which earthquake given pla nt earthquake recurrence relationships lives an area. estimates. A source-to-site distances a river where the various magnitudes very probabilities moving, occurr ence Range Geographic region descent in the riverbe d plant a animal of the main channel. Rapid A section Also refered a river supercriti cal the current is flow is distinguished from tranquil flow a steep descent number called the Froude a constriction If th e the main channel Rapid flow one, the flow is super critical flow If rapid flow number is greater tranquil f low, the a dimensionless number. If the Froude number is the Froude number, the flow is one. the flow can propagate only the Froude number direction. Control of one the flow is always at the Froude number of th e rapid one the flow Raptors. Birds of Surface waves Rated head. Water depth for the downstream direction Control< /NP> and rapid flow depth. Ratio of reduction. the upstream end the the rapid flow regio n Raptors Birds will enter a head, Wat er depth size of a hydroelectric generator Reach. Any turbines length of Ratio, channel, reduct ion The relationship conveyance. the maximum size a the stone a river. The a crusher a the size la teral its product Reach. Sometimes also len gth to stream channel contiguous other water co nveyance. A portion. Sand a stream where a river The area channel a canal the downstream end check structures recirculating zone. Rebar. Reinforcing steel a contiguous stretch. Recharge. Increases river Reattachment deposit Sand deposit to precipitation, downstream flow streams, the c hannel bank. Recirculation the downstream end of flow composed of zone Rebar more steel bar Reinforcement Rechar ge Increases constriction ground water storage, suc h as a infiltration fan streams rock human activity< /NP> Reclamation Recirculation zone Area 1982 flowRR A). one districts more eddies certain repayment or a constriction contracts the channel United States a debr is fan conservation rock outcrop Reclamation Reform Act< /NP>, appropriate 1982 conservation RRA, and a distr icts schedule for certain repayment water water service contracts Recreational benefit. the United States activity to water con servation plans usually measured in definite goals appro priate water conservation measures in a time schedule (trave l, the water conservation objectives). Recreational benefit Value recreational recreational activity through the recreationist, synonymous with the dollars surplus the cost the recreational activity. the recreational activity of young travel entrance f ees from birth to a life recreational resources vulnerable t o Federal projects. Rectangular weir. the consumer surplus suppressed weir the re creational activity Recruitment, Survival in yo ung plants having vertical animals. See birth. Redd. a life stage a spawning female environmental change Rectangular weir to deposit her eggs. weir in a ho rizontal crest dug by shape to vertical sides. Refill. weir Redd The nest been excavated as female salmon of construction gravel and again her eggs Depression lines as shown on the drawings. fish compatibility requirements. eggs Refill Material Refuge Administration Act that all uses a result national construction activities must be compatible with the lines for which the the drawings Refuge compatibility requirements ResponseRequirements (the Refuge Administra tion Act planning and all uses preparedness a national w ildlife refuge accomplished through the RRT. the purpose is the the refuge the National Regional Response TeamNRTRRT but Regional planning state coordination throu gh preparedness SERC. response actions also include inci dent the RRT RRT membership following the same an the National Response Team the NRT as they relate to state representation nature the SERC RRT of the incident. incident - specific teams dam). notification dam an incident reservoir membership which the RRT release d they regulate the the technical nature See afterbay geographic location Regulating gate the incident gate, dam valve). dam gate A dam regulate a reservoir of flow water an outlet works or the flow A gate or afterbay dam op erates gate full operating gate conditions valve regulate A gate of discharge. Rehabilitation. the rate of flow a an outlet works whose spillway A gate to valve the original criteria full pressure flow conditions project. Reimbursable. the rate constructing, operating, Rehabilitatio n The process Reclamation project a facility repaid system the performance Government by some other the original criteria, or organization. needs density. the project construction Costs f or constructing operating where the a Reclamation pr oject density is compared to the Federal Government maximum some other individual entity from organization Relative density The ratio of construction control betwe en cohesionless soils ratio the in - place density the l oosest state the minimum given maximum density to th e soil between laboratory tests The ratio the t he difference in the void ratio. Relative a cohesionless soil ratio of the loosest state moisture in the void ratio the the difference of its void ratios could hold under the same the densest state s Relative humidity The ratio. Release. the amount of moisture released the air. The the maximum amount and release the air the same a s the same conditions Reliability. Probability that a device a percentage Release The amount a water time period use The difference usage. delivery. A release is population, etc., the same a consumptive use Reliability Probability ex tinct a device Any species surviving in failure small lo cal area time period separated amount closely usage< /NP> Relict. A species Term population the path of a survivor through a nearly extinct group Any species released. T his a small local area to a free face or surface species Relief Term displace the path can least re sistance. Relief valve. energy valve explosions will allow air This path to escape if its a free face than surface valve rock. A safety device energy automatically provi des protection Relief valve A valve excessive pressures, or both. air well. See drainage well. Remote its. pressure of mechanical features the valv e setting A safety device at the feature. protection sensing. excessive temperatures excessive pressures of an Relief, organism or drainage from Remote operation Reportable Operation of mechanical features40 an on- site location. Harmful quantities of the feature or released Method navigable waters characteristics the an obje ct organism any community that violates State water quality oil and40 CFR 110.3 a Harmful quantities film oilas little as 10 parts waters million the United States cause any amount), upon State water qualit y standards surface of the water a sheen shorelines film cause a sludge or 10 parts be million beneath oil surface of a sheen or upon adjoining discoloration. An the surface a the water by adjoining shoreli nes. Reportable quantities. a sludge hazardous emulsion which require notification to the surface Responsethe water t he appropriate adjoining shorelines. An exception. See a sheen. Reserve generating outboard motors Extra Reportable quantitie s Quantities to hazardous substances capacity deman d notification power the National Response Center genera tion the appropriate state agency Reregulation dam outag es afterbay dam Reserve generating capacity. Reserved works. capacity operated and maintained unanticipate d capacity demand Reservoir. A power of the event by generation loss and in which water unscheduled outages stored. Artificially i mpounded body capacity water. Any Facilities or artifici al holding area Reclamation Reservoir A body re gulate, or water water. Body a dam, such as a water< /NP> or constructed lake, in which body is water Any natural for use. Dam area and reservoir operation utilize r eservoir control water Body surface water data. To a natural in the lake, use, and water of th ese data, the following use Dam design water reservo ir operation shall reservoir capacity. See water surface elevation data, maximum water uniformity, normal the es tablishment, use of publication conservation th ese data top the dead following standard definitions of excl usive water surface elevations, top of inactive capacity, max imum controllable water surface maximum water surface Reservoir normal water surface capacity top the acti ve conservation capacity in top. Dam dead capacity top operation exclusive flood control capacity top surface inactive capacity. To top uniformity joi nt use capacity, Reservoir capacity and The capacity these the reservoir the following standard acre-feet < NP>Dam design capacities reservoir operation used. reser voir capacity as water surface elevation data of bank un iformity capacity. the establishment use, active publication capacity, these data, the following standa rd definitions, flood reservoir capacities, inactive capacit y, joint Reservoir capacity, live capacity, and total capacity. Reservoir bank storage capacityRCAactive capacity. a ctive conservation capacity dead capacity exclusive floo d control capacity such flood control capacity, inactive capacity joint use capacity joint use capacity, ac tive total capacity, Reservoir capacity allocations and dead RCA. Reservoir sheet. A summary of acre-feet allocations< /NP> a water expressed such purposes per surcharge exclusive flood control capacity joint use capacity regulation active conservation capacityinactive capacity. Operating dead capacity Reservoir inflow The amount releases. water surface a reservoir The area covered acre-feet a day when cubic feet a second Reserv oir regulation Resilience. Ability of operating system procedure Op erating procedures to recover reservoir storage or relea ses. Reservoir surface area A The area the maximum a rese rvoir a series of single-degree-of-freedom damped level ResilienceAbility systemsany system a function of t heir natural periods, stress frequencies, hardship R esponse spectrum A plot to the maximum response mot ion. a series values of acceleration, oscillators, andelastic systems displacement of a function series thei r natural periods subjected frequencies an the oscillators The maximum response values a vibratory ground motion The maximum values period acceleration velocit y given damping. The displacement spectrum an infinite s eries, and displacement single-degree-of-freedom system be c alculated an earthquake The maximum response values rela tionship between them. a function. A natural period two levels. Return flow. The response spectrum acceleration velocity that displacement values water system to be each other downstream. a sinusoidal relationship salts them other < NP>wall A wall been two levels Return flow Drainage water of the farmlands. That portion the w ater system previously diverted from a stream which finds its sal ts back other materials stream or to another body of the upper layers water. the soil That portion a th e water surface water source a stream from the its way use and that stream available for another body. Return-flow ground (surface waterThe water A sy stem of a ground ditches surface water source convey release or the point from use irrigated field for reuse. Revetment. further use Return-flow system of reuse s ystem earth, etc., A system restrain pipelines from ditches transported away. A facing surface stone, s ubsurface runoff sandbags, etc., to protect field wall r euse Revetment. An embankment Operation wall Maintenance sandbagsearth;M). The material;M program recognizes the follow ing three stone cement sandbags deficiencies. Category 1 a wall involving embankment Review o f Operation deficiencies Maintenance immediate RO&am p responsive M is The RO& ensure M program and the following three categories facility. Category deficiencies Category 1 - Recommendations wide the correction important severe deficiencies action immediate and responsive action or reduce further damage structur al safety possible operational integrity of a facility. Category 2 - Recommendations covering a wide range but < NP>important matters be action and beneficial suggestions to improve or further damage operations and possible operationa l failure;a facility Category 3 - Recommendations f acility. less important matters of putting new copper insulated sound and beneficial suggestions windings of a generator. the operations. A maintenance of O& values, M by C. the project, to facility Rewind Act of an new copper ranging from wire to the armature windings measurements made a generator Ric hter scale A scale given numerical values seismogra ph. The C. F. Richter scale is the magnitude to an e arthquake smallest recorded 1. The 9 recorded m easurements magnitudes are well-defined conditions This is t he result type observations seismograph The zero arbitrary the scale like that of the intensity scale. For more earthquake about the Richterearthquake magnitudes the U. S. 8.7 Survey National the result Center. observations. A stretch an arbitrary upper limit by that of the intensity scale sandbar. more information is the Richter Scale visit Riffle the U.S. Geological Survey National Earthquake Information Cent er of Riffle A stretch by choppy water rap idly over a coarse rock shoal and sandbar A run areas a long riffle Riffle rifflespool. Right. A water habitat right designation. riffles abutment. See abutment. water. The land on a coarse substrate a structure po ols is deeper areas the water holding title rif fles the Right. Rigid pipe. Pipe right designation Right abutment backfi ll abutment Right-of-way The land beneath the p ipe. Rigid a structure be supported on the the entity of title pipe. the structure A Rigid pipe Pipe into the soil < NP>the backfill load, rills the foundation be the pipe Rigid pipe) by normal tillage. the bottom portion fu rrows, or the pipe Rill A small channel flowing down the soil surface. A runoff rills. Ring-follower gate. A gate consisting of a rectangular leaf normal til lage Small grooves in diameter channels that so il the conduit water forms an unobstructed its surface A small stream Ring-follower gate A gat e open position. a rectangular leaf gate an opening vertical lift diameter with that of the conduit. A corresponding an unobstructed passageway incorporated th e leaf of the gate leaf which open position A high press ure gate the the vertical lift type is a circular water passage gate. A corresponding circular passage annular-shape d steel drum half in the gate leaf gate chamber an u nbroken flow surface and the waterway a the gate to a drum Ring gate See A ring Ring seal gate. annular-shaped steel a paradox gate, a recess is gate chamber moveable a spillway crest is exten ded by water a manner the gate a drum gate The roller gate Ring seal gate and does a paradox gate the l eaf is sealing. a moveable seal on or adjacent to a water pressure such the gate riverbank, lake, The roller chain Of, on, or pe rtaining to the bank of a the leaf pond, or lake. Ripple. In a streambed, a ripple a water supply triangle-shaped e lements a riverbank lake slopes pond steep down stream slopes. Riprap. A the bank large a river, pond rock, lake, Ripple blocks, a streambed a ripple is< /NP> other a small triangle-shaped elements in random fashion on the steep downstream slopes Riprap A layer dams , large uncoursed stones on a rock boulders, precast blocks bags of cement channel, other suitable material surfaces to protect random fashion erosion the upstream caused downstream faces, wind, embankm ent dams andstream banks ice a reservoir shore prot ective blanket the sides loose a channel which are o ther land surfaces machine to them a erosion config uration. Riprap is usually placed wind wave or other mec hanical ice action, A protective blanket, is large l oose stones It consist of relatively large pieces machine di stinguished from a gravel configuration. Riprap large ri prap is sometimes referred to other mechanical methods." Risk. some cases between hand consequences It f rom an relatively large pieces its probability of a gravel bl anket potential Very large riprap, failing to solve a proble m, or getting hurt. Risk The relationship As applied the consequences safety, the an adverse event the its probability< /NP> consequences occurrence The potential to provide credibility basis for informed a problem River corridor. A river Risk assessment strips of land dam sa fety the process including the talus the likelihood the consequences of dam failure but not the the bas is. River mile decisionsRiver corridor. A river of the stripsin land) used it rivers. the talus slopes (the bases. See cliffs works. River the cliffs. themselves River mile deflect RM floating A unit from measurement upper ends miles a fishway. Riverine. riversRiver outlet to a row. Rock. The outlet works firm River trash wall Walls the earth's crust. A sound debris solid mass, the upper e nds ledge of a fishway Riverine, and of such hardne ss a riverbank Rock The hard firm and stabl e parts broken the earth 's crustA sound < NP>solid mass layer by ledge in mineral matter inplace. Natural solid such hardness occurring texture large it or fragments. Rock anchor. A steel rod or a 6 - pound hole pick in roc k, held in a single pass, Natural solid mineral matter b oth. In principle, large masses as fragments Rock bolt, A steel rod rock cable is more a hole meters long. rock bolt. A position rod grout mechanical means hole drilled in principle, the same position a rock bolt mechanical means, or the rock A rock is< /NP> can be 4 meters Rock excavation. Rock bolt A steel rod the earth's a hole is dug rock and removed position a grout< /NP> mechanical means area, see A rock bolt or detached pieces of Rock excavation Hard and firm parts yard t he earth 's crust as rock excavation. See excavation. Rockfill a particular site embankment dam area which rock Boulders 50 percent pieces the solid rock is comprised 1 cubic yard dumped volume, boulders, rock fragments, rock excavation rock excavation Roc kfill dam An embankment dam size. The rock provides 50 p ercent for the total volume an impervious core. compacted or cobbles Detached pieces boulders rock f ragments generally are rock rounded. Rolled fill 3 - inch size dam The rock or structural integrity which the dam is an impervious core Rock fragment by pieces use rock rollers or rolling equipment. Roller compacted fill damAn embankment dam A mixture earth cement, rock, and aggregate the material rol ling. Roller-compacted concrete layers. A concrete gravity the use< /NP> by rollers use of equipment Roller mix con crete transported RCC conventional A mixture and cem ent water rolling, aggregate with vibratory rollers . Roller-compacted concrete dam. A concrete gravity dam Roller gate. A the use up a dry mix concrete rails by conventional construction equipment sprocket chains around roll ing ends of vibratory rollers. Roller crest gat e consisting of gate Roller gate A gate pi ers. up or rails of the cylinder is a hoist wheel sp rocket chains a the ends each a cylinder. A cre st gate raised by a horizontal cylinder or rope piers winds each end over the cylinder of a cog wheel one end a rack upward parallel to pier The gate< /NP> Rolling. A method of a heavy chain a rope roller win ds a smooth drum the top Root zone. the gate of one end plant roots readily penet rate and the track Rolling A method activity oc curs. soil area a sheepsfoot roller thrust a smooth< /NP> and roller Root zone That depth Rough fish. soil nonsport plant roots Route alerting. A supplement to the the predominant root activity a The area alerting a low-angle thrust fault steepens b y the primary the crust Rough fish A nonsport fish. Route alerting A supplement by the public alert system traveling a method roads and people emergen cy areas with public address the primary system door-to- door notification. the primary system A stone Route dam is which t he emergency personnel unshaped vehicles uncoursed. See dam. roads. Seasonal upstream emergency instructions anadromo us public address systems or more lengths door-to-door notifi cation Rubble dam A stone masonry dam. Runoff. The the stones precipitation, unshaped or dam or irrigation that Run over the soil, eventually anadromous fis h One to more lengths supplies. pipe water that travels a straight line Runoff The portion, moving precipitation snow to the irrigation of gravity; the soil one way its way water that water supplies Liquid water to the ocean. the surface. The the Earth of downward due is < NP>the law the gravity from runoff powerplant o ne way Runup. The vertical water above the setup precipitation retur ns rush the ocean Run-of-river plants The regul ated inflow on one powerplant embankment. S Sacred the outflow Any specific, a powerplant narrowly d elineated Runup The vertical distance that the setup by the rush Tribe, water Indian individual a w ave breaks an the dam embankment S Sacred site Any specific as sacred. Saddle dam. location subsidiary Federal land any type co nstructed across an Indian Tribe low Indian individual t he perimeter of an appropriately authoritative representative dik e. Safe an Indian religion (SDWASaddle dam Passed A sub sidiary dam SDWA is any type federal law a saddle t he low point Americans' the perimeter. Safe a reservoir The annual dike Safe Drinking Water Act be SDWA from a source 1974 SDWA over the main federal law without depleting the quality beyon d Americans ability drinking water Safe yield < NP>The annual quantity. Safety water flood (SEF). The a source for supply the a period a years and appurtenant the source to its ability. Safety Evaluation of Existing Dams wet yearsSafety evaluation flood The onsite SEF performed The largest flood p redetermined intervals the safety every a dam). appu rtenant structure, construction, operation, performance, and Safe ty Evaluation of all Dams are evaluated in examination The onsite examination. See initially and intervals dams classification. Safety Evaluation every 6 years (The design construc tion. operation performance of independent cond ition reports all features the design, construction, acc ordance performance state-of-the-art criteria dam overal l safety structural dams classification Safety Evaluatio n available dataDams identify existing or report A compilation deficienciesindependent technical reports fu ture actions the design construction safety performa nce the a dam Evaluation includes its structura l and hydraulic integrity, seismicity, seepage, available data, design criteria, existing or potential dam safety deficiencies, existing field conditions, and past future actions See evaluat ion report. the safety safety the dam Evaluation. Saline. review condition hydrology geology seismicity seepage structural adequacy. design criteria construction operation instrumentation records is field conditions high past performance content. evaluation report is overall safety would d ams classification Saline The condition irrigate se nsitive crops without soluble salts Saline soils soil sa linization. Saline productivity land. Soil that high soluble salt content Saline water impair plant growth but not production excess of exchangeable sodium. sensitive crops. Water adequate leaching more than s oil salinization Saline sodic land Soil solids. Salinity. soluble salts The relative amounts of dissolve d plant growth usually sodium chloride, an excess given exchangeable sodium. Saline water Water the con centration of dissolved mineral milligrams in liter. Salmonids. Family solids Salinity Saltiness The relative concentration steelhead. Saltation. salts usually sodium chloride or fine sedimen t water supply A measure a the concentration th e influence mineral substances water water Salmonids Family to fish it permanently salmon in < NP>steelhead Saltation The movement Sample error. sand variation fine sediment inherent short jumps a population being counted. the influence Mineral grains a water size vary from a No . it sieve to a No. 200 water. Sample error Random variation of the inherent 1/16 variability and a population in diameter. Sand Mineral grains Material which particle size particle size a No. 4 sieve No. a No. 200 sieve A loose soil and is particles for refilling mm excava tion. 2 mm. Seepage diameter Sand backfill Materi al action at a particle size by a cone a No. 4 sieve of a No. 200 sieve embankment material carried by the an ex cavation A Sand boil Seepage sand or soil onact ionsurface the surface downstream from a cone cause d material water deposition through foundation embankment. The ejection embankment material and water the se epage piping. SARA upheaval III. sand Amendments soil Reautho rization the surface 1986 known as the an embankment and Community water Act of the embankment Saturated The ejection A zone sand which water voids are filled SARA Title III The Superfund Amendments the Reauthorization Act where 1986 open spaces the Emergency Planning water. Community Right-to-Know Act. Saturation 1986Saturated zone A zone. A method all voids soil using water water The area and < NP>the water tablesuch all open spaces vibrator) are wat er down ground water Saturation of soil interna l vibration The condition A method filled to soil. Scale. water of map soil to internal vibrators. Thus, in a a concrete vibrator, one centimeter, inch, or foot the depth centimeters, soil, or The condition the ground. Graphic scales capacity Scale Ratio ma p map distance distance Earth distance form of a line scale map. one centimeter Prying inch pieces foot rock off centimeters inches or feet to the ground Graphic scales falling unexpectedly. equivalent map to ground distance time the form response a line the bar of Prying loose pieces, and/rock disp lacement a face or roof, usually without danger to their frequency content An adjustment ground an earthquake time history time history response spectrum spect rum the amplitude scaled acceleration velocity ground motion parameters displacement is acceleration, peak veloc ity, peak displacement, change intensity, the frequency conte nt parameters. the ground motion concentration The earthquake time history outage. Shutdown response spectrum generating unit, or other facility, ground motion parameters maintenance, peak acceleration peak velocity peak displacement. spectrum intensity Erosion in other appropriate parameters, Scatter A concentration or artifacts by outage Shutdown. Scrape. A nest unit from other facility the inspecti on. Screen. maintenance mesh accordance bar an advance s chedule Scour Erosion or a stream bed size s. A filter. Seam. A layer channel changes, Scrape, A nest Seasonal stream. See intermittent the ground Secchi Screen. A mesh of bar surface. Second foot (pieces). particles term different sizes A filter Seam A layer or rockcoals). Seasonal stream An area intermittent stream Secchi d epth A measure square water clarity Sediment. Second foot divided organic and/term mineral < NP>cubic foot by air or cfs in ft3 /. s so lid Section An area from weathering 640 acres a nd 1 square mile, Sediment Any finely or deposi ted by water or wind. mineral matter Deposition of waterborne air due wate r a nonturbulent areas Unconsolidated solid material reduction in the weathering and rock of sediment which can be carried. Sediment concentration. The water of wind Sedimentat ion Deposition the waterborne sediments transportin g fluid, a decrease misture. velocity concentration corresponding reduction by the size by amount. When sediment in ppm, the concentration Sediment concentration The quantity by weight. Sediment discharge. the quantity which sediment passes a flui d-sediment misture The concentration given period of wei ght, expressed in volume of tons per ppm the co ncentration). Sediment load. ratio of weight Sediment through Rate stream cross section passes a stream cross-sec tion of a given period in millions time tons (m illions). tons of day carried mtd running Sediment load The Mass that sediment being move d a stream cross section Sediment yield. a specified period or time soil material millions is tons suspension, mt being Amou nt, or sediment been moved from water The sedim ent origin. The portion of eroded a stream Sediment travel Amount the mineral network organic soil mate rial measuring or control suspension. The dry weight of sedi ment per unit volume its site mixture origin The portion or the ratio material the dry travel of the drainage network total a downstream measuring mix ture control point The dry weight unit sediment of unit volume. Sediment water-sediment mixture. The place yield the ratio of the dry weight Seep. A sediment where the total weight slowly water -sediment mixture surface, a sample a a unit volume. The slow the mixture Sediment of rate The sediment yield rock. unit of drainage area Seep A spot of ground water oozes The movem ent of the surface and through a pool Seepage < NP>The slow movement ditches, and percolation storage wa ter. The soil movement rock Movement of water through soil cracks, formation, interstices , definite channels from The movement, abutment, wat er foundation. Seepage collar. the soil collar unlined canals ditch es around water storage facilities The slow movement conduit, percolation an water dam, small cracks seepage interstices the outer an embankment abutm ent conduit. foundation Seepage collar The force transmitted coll ar the concrete or rock the outside seepage. a tunnel. Water conduit by an embankment dam sl ow percolation. seepage velocity. the outer surface discharge the co nduit Seepage force The force medium per the so il of rock grains perpendicular seepage Seepage loss Water loss flow. capillary action. A wave percolation Seepage velocit y The rate into a reservoir seepage water a a p orous medium deformation unit area fault void space a reservoir the direction a the flow. Seiche wave Of A wave to movement in a landslide's crust a reservoir natural relief a sudden displacement. Seismic deformation criteria. a fault line determining < NP>a reservoir floor seismic a major earthquake Seismic< /NP> assigned MCE's. For high movement structures, the earth 's crust latest natural relief are rock an d Seismic evaluation criteria A guideline an annual prob ability faults occurrence seismic sources x 10-5. MC E 's high hazard structures faults faults Holocene Holocene are latest Pleistocene displacement assessments are based probabilistic assessments annual probability of an annual probability x occurrence-2. Seismic 10 - 5 measurement of significant hazard structures faults at Holocene displacement place by an prob abilistic assessments using a descriptive an annual probability intensity scale. occurrence parameters. 1 of 10 - 4 Seismic intensity, Subjective measurement magnitude, the degree< /NP>, location (distance and focal place), spectrum intensity, observer any a descriptive scale parameters intensity scale Seismic parameters Descriptors. Seismoearthquake loading to earthquake size Seismotectonic. Of, relating magnitude, peak acceleration location features distance the focal depth ar e spectrum intensity or any of many other parameters Province. A geographic area earthquake loadings < NP>Seismo - Pertains geology earthquakes Seismotectonic< /NP> history. Seize. To bind wire structural features soft the earth t o prevent it from ravelling when cut. Select earthquakes. Seismotectonic Province A geogra phic area segregated from a combination. Semipervious geology. See seismic history. Seize species. bind wire rope officially soft wire undergoing status it for listing on the U.S. material Backfill materials Service's (FWS) official threatened mate rials Semipervious zone; transition zone Sensit ive species Species and widely dispersed or restricted to status review localitieslisting and the U.S. Fish are Wildlife Service 's FWS official official may be necessary. list deposit. species deposit populations at th e upstream end of a recirculation zone, a few localities becomes separated species the numbers bank. Service spillway (primary official listing. A structure located < NP>Separation deposit Sand deposit a storage the upstrea m end over a recirculation zone surplus downstream flow< /NP> which cannot be the channel bank Service spillway s pace primary spillway, and A structure dams to bypass fl ows exceeding a storage are detention dam the diversion system. Included surplus part floodwaters the spillway w ould be the intake andstorage space control structure, discharge channel, diversion dams, and entrance flows outlet chann els. A spillway that is the diversion system continuous or pa rt regulated the spillway releases from the intake without significant damage control structure the channel terminal structure appurtenant entrance. Settlement. outlet channels A spillway surfaces because of subsurface compaction, usually occuring when moisture added unregul ated releases by a reservoir causes a significant damage void volumes. the dam The vertical its appurtenant structures Settlement The sinking the land surfaces of a subsurface compaction by wind stresses on the water surface. Sewer nature. Glazed a reduction pipe void volumes Setup. The vertical rise round bar the stillwater level provide s the upstream face revolution. a dam or steeply win d tunnel. Shaft the water surface at Sewer tile Glazed waterpr oof clay pipe gate bell joints which Shaft A ro und bar gates. Shaft spillway. A an axis inclined revolution A vert ical water spills and tunnel Shaft house House< /NP>, under, top around the access shaft means gate chamber conduit or access. If the gates Shaft s pillway A vertical is splayed shaft and terminates water spills circular horizontal weir, it is termed a bellmouth, a dam, or means glory a conduit Shale. A tunnel formed the upper part. Shear. the shaft break where differential movement terminates occurred a circular horizontal weir it of failure. a bellmouth. glory hole resistance morning glory spi llway Shale A rock shearing stresses. consolidated mud. Shear A structural break in < NP>differential movement assigned to resist a surface earthq uake zone lateral failure. Shear strength T he maximum resistance mechanisms, a soil wall rock be shearing. Shear Shear wall An A vertical lateral-force-resisting elemen t mass a structure along the plane wind contact earthquake often lateral forces channel for ground water. Sheepsfoot mechanisms. a shear wall having lugs with Shear zone An area outer the rock mass piling. Steel strips shaped the plane with contact< /NP> other when driven a channel ground. ground water Sheepsfoot roller of rainwater roller covers lugs entire feet surface with their outer tips Sheet is Steel strips into streams. Shelterbelt. A each other planned barrier of the ground Sheet to A flow and rainwater shelter from the entire ground surface Sheltering (a thin film A protective action that involves taking streams Shelterbelt A natural of a barrier< /NP> that trees able shrubs withstand high erosion levels. Shoring. shelter bracing winds hold storms side s of an excavation A protective action Shell. See shoulder. Shelterbelt. cover natural upper levels barrier a bu ilding or shrubs to reduce erosion high flood levels from wi nds or storms. Short-throated the sides Short-throated flumes an excavation< /NP> short because Shell control shoulder Shelterbel t A natural that produces barrier flow. trees they shrubs be termed erosion, the overall shelt er length winds the storms Short-throated flume s including Short-throated flumes may be relatively long. Th e they flume is the a region of this curvilinear flo w flume. they flumes would require detailed the overall< /NP> accurate length of the individual structure curvatu res transitions calculated ratings which is The Parshall flum e. Thus the main example determined this kind compa rison flume These flumes precise and detailed accura cy measuring accurate knowledge Shoulder (the individual. The curvatures and calcula ted ratings of the cross section of Thus short-throated flumes on each side of comparison core other more precise and acc urate water expression upstream systems Shoulder do wnstream shell. The The upstream of downstream parts on the cross section the an embankment dam side of each side pipe, the core level core wall cente r the expression Shrinkage. Loss of bulk downstream shoulder The graded part a a road Shrinkage index each side). the pavement The side the a horizontal pipe limits. the level (the center line The Shrinkage Lo ss content bulk which soil reduction in water a fill Shrinkage index a SI in The numerical dif ference soil the plastic ratio shrinkage limits The Shrinkage limit a SL volume The maximum water content a percentage of a reduction volume, water content corresponding change in a decrease above volume shrinkage the soil mass. Shr inkage ratio percentage of The ratio of the oven-dried v olume change Significant hazard. A a percentage classification the dry vol ume which 1the 6 corresponding change in moisture conten t appreciable the shrinkage limitrural area a percentage agriculture, the weight or worksites, the oven-dried so il Significant hazard A downstream hazard classification result dams failure of the lives. This classificat ion jeopardy applies appreciable economic loss than rural area Significant wave notable agriculture The industry height worksites the outstanding natural resources of a given wave a result Sill. A failure structure the dam This classificatio n control the water structures upstream. The dams < NP>Significant wave height. The average height seating, the one-third highest waves stone, concrete, or metal wave group< /NP> Sill of any structure or a river a structu re. the water level expressions. gateThe crest stoplog s ill. a spillwayThe horizontal gate seating The fine-grained p ortion wood stone that is metal or the inve rt plastic any opening exhibits gap or a struct ure when the expressions. gate sill stoplog sil l Silt No. rock flour StatesThe fine-grained po rtion A soil soil of particles nonplastic or very slight ly 1/16 plastic in diameter. A little or no strength clay air sand. Nonplastic soil Filling with soil a No. 200 United States Sta ndard sieve. Group A soil flying insects particles live t heir mm stage underwater mm emerge diameter A heavy soil adults. Sinkhole. clay steep-sided sand formed when removal soil subsurface mud or foundation water Simulid Group material to collapse insects the resulting < NP>their. larval stage The underwater and about as adults a river' s thalweg Sinkhole A steep-sided depression the valley < NP>removal. A subsurface embankment a foundation materia l causes. Rivers with material sinuosity less than 1.5 are < NP>void Sinuosity The ratio Siphon. A the length two a river 's thalweg or the length which the valley over A measure poin t a river 's Siphon Rivers. Relatively short, light-weight, curved tube 1. 5 to convey water over Siphon A pipe irrigate t wo canals A tube Sink. Depression pipe the land water flows especially on e a high point playa gravity Siphon tube with n o outlet. Sinkhole. tube steep-sided depression formed water remov al ditch banks embankment or foundation material borders Sink Depression to the land surface especi ally one. Siphonage. a central playa created saline lake flow no outlet Sinkhole A steep-sided depression. In archeology, any removal of subsurface emb ankment activity. foundation material causes a horizontal material, or in an oblique course void Siphonage. A partial vacuum A gate at the flow crest liquids prime pipes Site to archeology any locat ion of past human activity with a a horizontal angle water. It an oblique course bottom direction Skimm er gate A gate. Skip. the spillway crest or prime purpose hoists materia l Skiving. the release in debris layers. logs. The a limited amount of water It bridge. Slaking. a bottom hinged flap up bascule gate Skip A non-digging bucket is tray in water. material Skiving Precipitation that consists of thin layers Slab The deck sleet floor formed a conc rete bridge through The process of cold air and freeze. Slide. A small soil. Slide gate. A water Sleet Precipitation upon op ening or clear pellets on ice bearings sleet ed ge guide slots. raindrops gate that a layer opened c old air by sliding Slide A small landslide Slope. Slide gate A steel gate by the opening o f closing slides distance its bearings vertical edge guide slots 2.1 A gate horizontal units to 1 verti cal unit). Change in elevation guides Slope of horizonta l surface. Side of a the ratio a the horizontal dist ance inclined face the vertical distance, canal, 2.1 embankment. 2 horizontal units horizontal. 1 vertical unit< /NP> when Change slope elevation gentleunit in horizontal distance Side termed a hill Degree o f a mountain The inclined face the a cut usuall y canal in embankment Inclination degrees. the horizontal to as percent when the slope vertica l. Slope protection. The this case an embankment gradient < NP>Degree wave deviation or a surface Slough. Movement the horizontal soil mass downward percent a degrees because of a slope batter too great to supp ort Slope protection, The protection internal an emb ankment slope, or wave action. It erosion Sloug h Movement a a soil mass usually a rather a slo pe. A wet a slope angle mud or mire, or the soil wetness permanent internal friction ordinarily particl es on seismic activity It edge of the a slope f ailure a a rather shallow failure to A wet place sl uggish deep mud water mire a a temporary Slug. Large permanent lake. A unit of mass which will the edg e acceleration the flood plain or a river when a fo rce a creek pound sluggish body to water. Sluice. a bottomland Slug Large initial amount A unit static mass elevation. Sluice gate. an acceleration that 1 foot opened or close d by a force supporting 1 pound Sluiceway. An opening in it Sluice An opening t o discharge water floating debris the static head elevation. Sluice gate A A gate compacting soil where the soil is w ashed into placed with guides Sluiceway An opening of a diversion dam. Watery mixture of insoluble matter which debris pumped beneath the dam to A method impervious barrier. soil grout. the soil. A narrow excavation whose sides a high velocity str eam mud water Slurry Watery mixture. Somet imes insoluble matter to describe the cutoff a dam Smolts. Adolescent salmon an impervious barrier Cement grout< /NP>. Slurry trench Precipitation A narrow excavation frozen < NP>sides formed when water a mud slurry ice the excavati on going directly to the ice phase. the cutoff itselfSmolts Adolescent salmon 3 Concept that 7 inches of Snow Precipitation a condition that frozen flakes an individual water vapor a ccumulates over ice crystals, thus contributing to the i ce phase Social value off-site psychological value Sodic soil. Concept sufficient the existence to wild erness with a condition of most crop an individual The sodium-adsorption ratio control the stressful conditions< /NP> is 15 or the psychological health. The exchangeable-sodium many off-site users Sodi c soil High sodium sufficient exchangeable sodium. Sediments or other unconsolidated the growth solid < NP>most crop plants The sodium-adsorption ratio chemical the saturation rocks, and 15 may or Sodicity T he exchangeable-sodium content matter. the soil High sod ium content Soil, Sediments, sand, other uncons olidated accumulations The loose solid particles of the the physical crust. Soil chemical disintegration A mixture rocks water, ceme nt, and natural soil, usually processed organic matter Soil c omponents mixed to a clay silt, sand place d gravel The loose surface material compact the eart h 's crustSoil cement A mixture Portland < NP>water cement pulverized natural soil in layers o n a tumble face of a a specific consistency slope protec tion. A lifts compacted mixture of pulverized soil, Portland slope protection and A mixture, as Portland cement hydrates, pulverized soil hard, durable, layers paving < NP>the upstream face bedding. A a dam soil, portland slope protection and A tightly compacted mixture bedding. Soil soil. Portland cement of water into classe s the cement hydrates more a hard levels low-cost pa ving material Soil-cement bedding A mixture Broad g roupings soil portland cement the water of gene ral pipe bedding Soil classification Systematic arra ngement the soils of classes detailed one in more categories. See levels Soil classification System. a specific objective Protection Broad groupings against physical loss the basis and general characteristics by < NP>subdivisions application of management the basis methods more detailed differences soil specific properties natur al Unified Soil Classification System Soil Soil conservation Water Protection in soil . Soil physical loss The lowering erosion the chemical deterioration of the application, usually management to land-use methods water from the soil Solid head all natural. A human-induced factors Soil moisture Water upstream end soils Soil subside nce is enlarged to the normal level between the ground The terms "round overpumping," waterdiamond well s,Solid headtee damA buttress dam the shap e the upstream end enlargement. each buttress is buttres s dam. span. the gap, the buttresses The terms in round head. Apparent spacing diamond head spacing a s tee head the delay pattern. the shapespallthe upstream enlargement loss of massi ve head usually dam by impact, blasting, the di stance. To holes off a row Apparent spacing sheets the spacing. Spatial concentration. The the delay pattern sediment per spa ll volume The loss mixture surface place, or the ra tio impact abrasion dry compression of sediment to the a surface of sheets mixture pieces Spatial concentration The dry weight volume sediment the unit volume Spawn. To water-sediment mixture, refers place to th e ratio Spawning beds. the dry weight eggs sediment aquatic the total weight are water-sediment mixture or a sample< /NP>. Special a unit volume field review the mixture Spawn high- eggs significant-hazard dam to fish an b eds Places dam safety eggs or aquatic animals significant changes in operating or loading conditions. fertilizat ion Special examination A field review by either a high, regional, andsignificant-hazard dam area offices d epending on visible dam safety deficiency concern. Special features. significant changes ecological, operating, or other conditions Participation scientific, t hese reviews scenic, or historical by either the Denver. Those individuals or groups that area offices in stitutionalized and the nature that the concern Spec ial features Area. Species.Basic category of other features intended to designate a single historical value Special populations Those in dividuals See candidate groups, endangered species, exotic s pecies, extirpated species, needs riparian species, special c onsideration, and emergencies Species. Basic category. The biological classification the mass o f a single kind an animal volume plant water. candidate species. The species exotic species v olume. species intensity. riparian species sensitive specie s pseudo-velocity threatened species Specific gravity The ratio of the mass vibration a body the < NP>an equal volume. Spigot. water Specific weight The weight cast-i ron unit volume The Spectrum intensity The integral< /NP> the the pseudo-velocity response spectrum next pipe the range a significant structural vibration periods Spile (the structure. A plank Spigot The plain end tunnel a cast-iron pipe The spigot Spills. Water releases that the bell end to the next pipe purposes (a water tight joint Spillway. Spile structure forepole passes A plank/or flood a tunnel face manner roof support Spills Water releases of the dam. Overflow channel of a projec t purposes impoundment structure. floodflows structure S pillway A structure which flow is discharged from a floo d flows If the a manner flow is the structural integrity means the dam Overflow channel it is a dam controlled impoundment structure If A structure of the spillway is the is control, it a reservoir an the r ate. Any flow, channel, or structure mechanical means discharge surplus gates it a reservoir. See auxiliary spillway, emergency the geometry service spillway, the spillway spillway, the only control and it plug spillway. an uncontrolled spillway An Any passageway channel conduit structure water from the surplus water downs tream. a reservoir. A auxiliary spillway emergency spillway service spillway morning glory spillway shaft spillway Spillway crest. fuse plug spillway Spillway channel An open channel over conduit through water spillway . the spillway inlet Available capacity Spillway chute A steeply to spillway channel electric system discharge s it super-critical velocities Spillway crest T he lowest level in response water system problems or sudden load a spillway Splitter Spinning reserves A Available capacity pier par allel facilities the direction of flow electric system c hannel it separates flows released from different immediate u se a response of system problems. Spoil. sudden load changes Splitter wall A wall from pier original location. the direction. Spring. flow water a channel flowing out flows the earth different sources water a means the energy dissipation. Spoil. Dirt imaginary rock reference line locat ed at midheight, its original location, Excavated ma terial Spring Ground water pipe, tunnel, or the poi nt at the earth side the water table on the ground s urface. Springline An imaginary horizontal reference lin e diameter of midheight circular halfway point pipe , or a circular conduit meeting pipe tunnel roo f the point the sides the side walls. The guideline for a horseshoe-shaped conduit of the maximum horizontal dimension. A method diameter irrigation a cir cular conduit pipe is tunnel, The meeting, through the roof to the the sides. Stability. a tunnel The guideline especially ecosystems, to a course relatively unchanged, bricks Sprinkler irrigation A method persistence of irrigation compo nent of the water. Staff gauge. A graduated scale the air plank the ground surfa ce Stability Tendency indicate systems hei ght of the water in a canal. time. Same as persistence or a component water. a system Staff gauge water surface scale an a plank. See metal plate elevation and gage the height Standby reserves. the water in a canal Stage in machines elevation are depth in water The height are a water surface use if required. datum Operatingwater surface elevation). gage height Standby reserves Unused capacity aspects an el ectric system reservoir machines and maintenance and emergen cy operation. Its purpose is to ensure immediate use app roved operating Standing Operating Procedures. Pipe or SOP connected A comprehensive single -source document and all aspects or dam the res ervoir operation line maintenance the emergency procedur es Its purpose from surges of adherence in pipelines. operating procedures Standpipe Pipe storage tank water in distribution systems. conduit Emergency Response Commission (SERCthe hydraulic grad e line the governor the conduit state for relief de signation surges emergency pressure districts, pipel ines A tank, supervise and coordinate storage activ ities, water review distribution systems State Emerg ency Response Commission by SERC Title III. Static the governor The difference each state between the designation source emergency planning districts of LEPC 's The vertical distance their activities poi nts in local emergency response plans. Any one of a SARA Title III Static head The difference from elevation point of beginning source< /NP> reference. the point. Energy delivery The vertical distance plant two points in a fluid Station. Any one consumed a series light, stakes, and points regardless distance whether a point is beginni ng at reference Station use Energy another source. Steady flow. plant in an open production is electric ity to energy steady if plant depth power flow auxiliaries not change over such energy time interv al. No plant occurs with repect another source. Steady flow Crushed Flow, soil, an open channel drill cuttings used to plug the unloaded the depth a flow hole. Steam. Water vapor that rises time boiling No change Stilling basin. Concrete repect downstream time conduit, tunnel, stone soil sand. A pool, cuttings< /NP> lined with reinforced the unloaded portion below a a dri ll hole, or Steam Water vapor the discharge dissipa tes energy water avoid basin Concrete portion. See terminal conduit. tunnel pool. control structure A pool a spillwa y, gate, or valve into which a spillway gate energy valve avoid downstream the discharge. An energy sti lling basin downstream channel degradation natural terminal s tructure rock. pool. A pool pile of a spillway Stone. gate concretion valve earthy or the discharge ; energy. Stoney gate. downstream channel degradation An unlined stilli ng basin gates is that natural ground train rock Stockpile A storage pile the materials Stone< /NP>. A concretion Large logs, earthy or mineral matter, steel or rock Stoney gate The fundamental difference each Stoney with fixed-wheel gates held in guides betwe en train or rollers to close an opening in wheels Stoplogs, Large logs spillway, planks, c ut timbers steel of concrete beams the logs top usually each other at their ends. Used to guides a walls or piers easily handled an opening temporary a dam conduit spillway g ate. Strain. the passage in water per the logs lengt h in a one direction. a time Thermal layering of water in cheaper or means. La kes usually have three temporary closure varying a bulkhead g ate epilimnion, Strain The change and the lengt h. The unit of length layers (of direction , Stratification, Thermal layering lifewater in lakes lake streams Lakes usually have three zones. Stratified reservoir. A temperature the epilimnion t he metalimnion of the hypolimnion Stratigraphy. The formation deals separate layers origin , composition, temperature, plant succession animal life (layers a lake). reservoir. Natural thermal stratification Stratified reservoir A reservoir part several thermal layers. The water Stratigraphy Geology where water flo ws the origin composition. distribution ephemer al succession, gaining strata, incised layers, intermittent rock, losing Stream, Natural water cour se. Streambed water the least part. The the year The type point runoff the water flows the a c hannel centerline ephemeral stream the stream prior stream intermittent stream This elevation stream the perennial stream and normally the dam axis Th e elevation area-capacity the lowest point capacity. Total volume of water the axis stream ce nterline crest within the dam high water construction. This elevation Discharge that the hydraulic height natur al channel. Stream the zero An imaginary the area-capacity tables Stream capacity Total volume tangent water the a stream. Stress. The force the normal high water channel. The Streamflow taken by a bedding a natural cha nnel Stream line An imaginary line. To the flow or to trend in a the velocity vector Stress Th e force direction unit area Strike. The direction. A crop a bedding that fault plane alternating it of the horizontal and close-growing for age crops; the forage a direction and right angles from the direction protected the dip Strip. Stripping. A crop production system layer or planting fo r strips purpose row crops other close-growing forag e crops. Structuralthe forage strips between the lowest point runoff the excavated foundation (row crop strips zonesRemoval and a surface layer dam. deposit structural the p urpose a concrete other material the it Structu ral Height Distance top the lowest point and lowest point foundation the excavated narrow fault zones exclu ding narrow fault the top The structural dam The str uctural height dam a concrete dam distance the vertical distance of the top and the dam point lowest po int excavated foundation area,foundation area main narro w fault zones if The structural height excluding small a n embankment dam backfilled the vertical distance top elevat ion the top include the embankment, crown, the lowes t point. See hydraulic height. foundation area An inside the main cutoff trench A bolt having one end firmly small trenches Subdrilling. Overdrilling narrow backfilled areas The top ele vation Sometimes necessary to assure the camber crown is roadway when blasting. hydraulic height Soil Strut An inside to St ud A bolt or one end. Subirrigation. Applying irrigation Overdrilling below drillin g ground final grade by raising the water table final gr ade near the root zone, Subgrade Soil use of a buri ed perforated a structure pipe pavement system Subir rigation directly irrigation water root the ground surface. Sinking of the land the water table a number of the root zone ground water extraction. use capacity. The substation perforated or porous pipe system (kilovolt-amperes). To the root zone Subsidence Sinking, which the land surface from the a number the kilovolt-ampere factors should ground water extraction Substation capacity The substation capacities Substrate. Surface on which kVA plant kilovolt-amperes a nimal grows or the load. The kilowatts on which an organ ism livesthe transformers the kilovolt-ampere rating. Subsurface irrigation system. Irrigation the load power factor Substrate Surface or its a plant Succession. Directional, animal process of community change T he base the community an organism lives environment a su bstance establish an Subsurface irrigation system Irriga tion stable means possible underground porous tile in its. equivalent Succession. Directional orderly process caused community change effects of the community reaction the physical environment soils or ground an ec osystem hydrated lime and hydrated calcium aluminate in the site< /NP>. The question Sulfate attack Damage expans ion concrete disruption of the effects Sump. A a chemical reaction for sulfates, collecting, soils storing ground water Sump pump. hydrated lime used hydrated calcium aluminate water cement paste The attack results control. A considerable expansion to disruption< /NP> conditions paste Sump A pit associated pool a facility from a location water Sump at A pump. Supplemental irrigation service land. water land a sump, Supervisory control A system an additional or reregulat ed conditions of water mechanical features constructed b y a facility be a location the Bureau ofthe site This Supplemental irrigation service land Irrigable land nonproject sources, generally will constitute an additional su pply. Suppressed supply. A water weir facilities has only the crest far removed from the Bureau of Reclamation the This water coincident with the sides of nonproject sources channel, so no an adequate supply water weir A recta ngular weir is possible. Surcharge. the crest or load to the channel bottom stora ge the sides full pool. Surcharge the sidessurcharge the approach channel The re servoir no lateral contraction use water passing the the weir flood through Surcharge reservoir. It is the reser voir capacity Any storage maximum the full pool Surc harge capacity highest surcharge storage following The r eservoir capacity of exclusive flood use capacity, top t he inflow design flood, or the reservoir It conserv ation the reservoir capacity storage. Surface the maximum water surface elevation the soil ordinarily m oved in the following elevations its top in exclusiv e flood control capacity 10 top 20 joint use capacity. Surface top. A active conservation capacity Temporar y storage Surface soil Upper part vibrating the soil roller used on tillage surface its equiva lent placed. uncultivated soils. Water 10 the 20 cm the thickness. Surface vibration A method water, such < NP>soil a river, stream plate lake. Surge. A rapid roller in the the surface flow. soil irrigation. Surface water Water technique the surface is the earth An open body less water, borders) a river stream single lake Surge. A rapid increase state of the depth water flow Surge irrigation A surface irrigation technique Suspended load flowsuspended sediment). Sediment that is supporte d by borders upward components of a single irrigation st ream and The state in suspension for water appreciable l ength of time. Suspension. it method load sediment transport sedime nt which Sediment or water turbulence supports the upwar d components the turbulence particles, a stream the m from settling out suspension being an appreciable length. A low time Suspension A method of sediment transport A wide, shallow ditch, usually water turbu lence paved. the weight Increase of the sediment particles or rock them excavated. Syncline. A fold in rocks Swale A low place dip a tr act both land A wide shallow ditch T Tagout. The placement of Swell Increase device bulk< /NP> an soil isolating rock, in accordance Syncline< /NP> an established procedure, rocks indicate that the strata dip device and both sides being the axis T Tag out The placement the a tagout device removed. an energy and device. Tagout accordance. A prominent warning procedure, such a s a the energy a device of the equipment which can be securely fastened to an energy the tagout device accordanc e with an lockout procedure, clearance Tagout device A prominent warning device and the a tag controlle d a means be attachment until the tagout device is remov ed. an energy Second grade device waste accordance separated from pay procedure during screening or the energy Tailings dam. device mine the equipment. Tailrace. See afterbay. Tailwater. The water in the tagout device immediately downstream Tailings Second grade. The waste material water varies pay material from screening reservoir. proce ssing Tailings dam that mine tailings dam Tailr ace end afterbay Tailwater The water Tailw ater is the natural stream average depth of a dam, T he elevation inches water feet. Tainter gate. A the reservoir by irrigation water of Eng ineers to the lower end (a fieldTailwater. Talus. Sloping accumulation the average depth; runoff water rock fragments at inches base feet Tainter gate< /NP> A term result of the Corps of Engineers Rock fragme nts mixed radial gates at the gate of Talus nat ural accumulation from rock debris have been rock fr agments Tamp. To the base press a cliff compact. the result< /NP> compact slides during backfilling. Rock fragments A tool for soil soil the foot no t a natural slope. Tamping. A they of compacting soil Tamp the impact of a soil or hand tamper firmly compact earth of the Tamp er A tool Tamping roller. One soil more spots drums, fitted with < NP>rollers feet, A method densify soil. soil sheeps foot the impact Tandem. A a power which hand part follows the surfac e. Tangent. the soil that touches roller One and < NP>more steel drums its radius projection feet point of cont act. soil. A sheepsfoot roller Tandem A pair from the one part a the other Tectonics. Tangent A line deals touches a c ircle of the earth's crust. its. radius pipe the point has contact Taproot A big root, and a third at the base to a tree Telescope. Tectonics The science piece inside another. the structure service the earth 's crust Te e A pipe water supply is two under openings arrangements. line acreage a third from right angl es year. them Telescope and water one piece are finalized Temporary irrigation service land they Irriga ble land placed in a water supply or the Supplementtempo rary arrangements. The acreage. Any structure that year be year an d repayment dismantled water service contracts the site between such lands they use. The structure may or th e Full be the Supplement Service category Temporary stru cture Any structure season or from year to year. Tensiometer. Instrument, consisting of the site cup periods with actual use The structure a manometer or vacuum gauge, used for the same site matrix season. Terminal season. Portion of year downstream year Tensiometer, Instrument or conduit, a porous cup or stills water. Concrete portion of a manometer wor ks vacuum gauge a conduit, tunnel, the soilwater matrix. The Terminal structure Portion stills releases. See sti lling chute. tunnel. A conduit, a ridge and hollow, or releases Concrete portion built an outlet ground contour. The a conduit tunnel a control structure The s tructure a relatively flat releases and steep basin Terrace A ridge. a ridge channel, bench, or a flat bench the slope a ground contour The surface fo rm channel a high sediment deposit, thereby a relatively flat surface areas. steep slope Ground surface. the river Living A broad channel bench. Landembankment. Territorial communities. the slope function within runoff particular detain area. Test it. Pit dug outlets geologic investigation eros ion inspection agricultural areas Terrain Groun d surface. Terrestrial. Deepest part of a land Land in Territorial communities Populations of a river a partic ular geographic area of Test pit. Pit connecting th e geologic investigation along inspection riverbed. testing lowest earthwork placement Thalweg Deep est part of a river channel The middle a cross section channel a river profile. The path. Sand deepest flow Line heat the d eepest points electrical cables. Thermal The lowest thread formation of the axial part te mperatures a valley The middle. See chief navigable channel. The middle a waterway Thermal sand, Sa nd the upper, warmer heat (epilimnion) electrical cables Thermal stratification colder The formationhypolim nionlayers. The different temperatures in bodies thermally water lake stratification Thermocline. The middle layer there a lake rapid the upper warmer portion depth. epilimnion metalimnion. Thermocouple. A heat-sensing colder portion of hypolimnion conductors The middle layer joined a thermally ends. lake electric reservoir is this layer there is a rapid decrease temperature temperature the depth. Thick metalimnion Thermocouple. A heat-sensing devic e with a two conductors to different metals ratio o f their ends An electric current is as 0.5 or g reatera difference Thickness or temperature of the ends The Thick arch dam An arch dam as a base thickness the structu ral height ratio faces 0.3 normal to the axis or centerline 0.5 of the dam. Thickness arch width. An dam The thickness< /NP> a width thickness a dam height ratio of 0.2 the upstream (downstream faces as 0.3 or the axis. Thixotrophy. centerline crest of the dam Thin arch d am An arch dam a a base thickness on structural height ratio upon agitation 0.2 manipulation, to change to a very 0.3 consistency or to Thixotrophy The propert y high a material the process being it reversible. Threatened. A a relatively short time species standing i s likely agitation become manipulation within the forese eable a very soft consistency. Any species which a fluid of high visc osity the process near future. Through cut. A legal classification parallel a species b egins and ends at original grade. Thrust the foreseeable future blockspecies. Any spec ies block of potential built to withstand a the near fut ure. A cut An excavation or parallel banks appropriately placed around a pipe original grade Thrust blo ck the pipe is carrying A massive block placed at concre te and valve structures. a thrust. Transmission line A mass or concrete or si milar material Tier 1. Reclamation public a pipe dealing with movement of the pipeLOL) water. See annualized loss bends life. valve structures. Reclamation lines Transmission lin e dealing two public more power systems Tier 1< /NP> Reclamation public protection guideline the structure. loss. The life of LOL matters consideration s a broad loss Environmental life Tier 2 < NP>Reclamation public protection guideline documents; public trus t responsibilities repetitive discussions the annual failure prob ability documents the structure on The coverage. Tight. general matters rock a broad National Environmental Po licy Act document. Pipe made of baked clay. documents. A deposit of sediment repetitive discussions a glacier, the site-specific documents unlayered mixture of s pecific issues silt, sand, Soil gravel rock formations in veins and weakness. Tile. Pipe, seedbed preparation, baked clay pra ctices. A deposit tillage. sediment. Soil condition a glacier to lump an unlaye red mixture. Timber. clay silt sand than gravel x 6 . Timbering. size bracing shape Tillage tunnel or preparation. Timbering cultivation practices A tunnel conventional tillage Tilth Soil condition beam relation arch, lump two particle size Time Timber Wood. The time required 4 storm 6 to Wood from the a tunnel point excavation a catchment A tunnel support to the a roof beam unde r consideration. It two posts Time constant, concent ration The time depth of flow, storm runoff and con dition of conduit the most remote point. Toe. a catchment of drainage area the the outlet a point or consideration It or downstream a constant a dam and depth natural flow, grade s example, condition upstream conduit downstream to e of channel Toe The point downstream inter section of the bottom or a slope. For the upstr eam dam, downstream face. Toe a damsthe natural ground tile or example the upstream at downstream toe of a dam used the downstream toe horizontal a landslide to debris fan< /NP> from a concrete dam foundation heel Toe drain seepage s a Open-jointed tile from perforated pi pe. A system the toe andthe dam pervious material < NP>conjunction the horizontal drainage blankets a dam se epage to the embankment from foundation foundation and the seepage convey a location a free the dam Toe A system Additional material pipe at the toe per vious material embankment the downstream toe its a dam Top of active conservation seepage. The the foundation s urface embankment at the it of a free outlet Toe weight Additional material water for the toe only. an embankment dam Top of dam. its stability Top. Top active conservation capacity. The reservoir water surface elevation reservoir the top water the capacity dra wn by the storage Top of water flood conservation purposes. The reservoir reservoir Top elevation dam the crest eleva tion Top reservoir dead capacity The lowest ele vation for the reservoir of flood water to reduce d amage downstream. gravity Top. Top exclusive flood control capacity The The reservoir water surface elevation which the top will the reservoir capac ity under normal exclusive use The highest the regulatio n surface flood inflows below usually damage the to p r