- Browse Related Terms: AAM, AGM, Average, B/C, Capital investment, Index of Wetness
A Weather Service form documenting station management, exposure, topography, driving instructions, payment information, hydrometeorologic equipment, and observing information.
- Browse Related Terms: ASOS, B-44 Form, Cooperative Station Report, Climate, Congressional Organic Act of 1890, County Warning Forecast Area (CWFA), Hydrologic Service Area (HSA), Hydrologic Services, Hydrometeorological Report (HMR), Mission of the National Weather Service, National Interagency Fire Center (NIFC), National Weather Service (NWS), Regional Operations Manual Letter (ROML), Warning stage, Weather Forecast Office (WFO)
biological assessment.
- Browse Related Terms: [Marine] Natural Resources, BA, BO, BRD, Human environment, Psychological value., Succession
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A pressure that can cause water to backflow into the water supply when a user's water system is at a higher pressure than the public water system.
- Browse Related Terms: ASCC, AVADS, back pressure, Baseload plant, Control area, Coordinated operation, Coordination, Distribution system, Grid, Independent System Operator (ISO), Interconnected system, Interruptible demands, Interruptible load, Open access same-time information system (OASIS), Operational waste, Operations and maintenance costs, Parallel path flow, Power pool, Resilience, Standby reserves, Tie lines, Voltage reduction, Western Area Power Administration (WAPA)
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Material used in refilling excavation, or the process of such refilling. Material used to fill an excavated trench.
- Browse Related Terms: Backfill, Backfill concrete, Borrow, Borrow areas, Borrow pits, Cutoff Trench, Cutoff trench (keyway), Dam foundation, Embankment Dam (Fill Dam), Embankment dam or fill dam, Exploit, Fill Dam, Payline, Pipe trench, Pit run gravel, Refill, Sand backfill, Select material, Slurry trench, Uncompacted backfill, Unsuitable material, Wastebank
Concrete used in refilling excavation in lieu of earth material.
- Browse Related Terms: Backfill, Backfill concrete, Borrow, Borrow areas, Borrow pits, Cutoff Trench, Cutoff trench (keyway), Dam foundation, Embankment Dam (Fill Dam), Embankment dam or fill dam, Exploit, Fill Dam, Payline, Pipe trench, Pit run gravel, Refill, Sand backfill, Select material, Slurry trench, Uncompacted backfill, Unsuitable material, Wastebank
A reverse flow condition, created by a difference in water pressures, which causes water to flow back into the distribution system.
The backing up of water through a conduit or channel in the direction opposite to normal flow.
- Browse Related Terms: Anisotropy, Backflow, Divert, Energy grade line (EGL) (energy line, energy gradient), Equi-Potential Line, Flood Profile, Hydraulic grade line (HGL) (Hydraulic gradient), Hydraulic Permeability, Jetty, Seepage velocity, Splitter wall, strain, Transformed flow net, Unit hydrograph
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The first cut of a plow, from which the slice is laid on undisturbed soil.
- Browse Related Terms: Angle of repose, Arable, Backfurrow, bedding, Borderline soils, Consistency, Flexible pipe, Fossorial insects, Heap, Mud, Perched Water Table, Permafrost, Pile, Plastic soil, Primary excavation, Silting, Soil moisture, Soil-cement bedding, Surface soil
A rod reading taken on a point of known elevation, a benchmark or a turning point. Backsights are added to the known elevation to arrive at the height of the instrument. With a known height of the instrument, the telescope can be used to determine the elevation of other points in the vicinity.
- Browse Related Terms: Area-Capacity Curve, Backsight, Bench mark (BM), Capillary rise, Contour, Cross-section, Discharge Curve, Drop structure, Finished grade, Foresight, Maximum controllable water surface, Maximum Spillway Discharge, Mean sea level (MSL), Prescribed elevation, Reference Mark, Spillway crest, Top of dead capacity, Turning Point, Turning point (transfer point), Waterstage recorder
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A form of backflow caused by a negative or below atmospheric pressure within a water system.
- Browse Related Terms: Backsiphonage, Breakup Jam, Flocculation, Floe, Hanging (ice) dam, Hummock, Ice Gorge, Ridge
A small, generally shallow body of water with little or no current of its own. Stagnant water in a small stream or inlet. Water moved backward or held back by a dam, tide, etc.
- Browse Related Terms: Backwater, Braided Stream, Caisson, Catchment basin, Coulees, Dendritic, Eddy, Gaining stream, Losing stream, Main channel, Mainstream (mainstem), Pool
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The longitudinal profile of the surface of a liquid in a non-uniform flow in an open channel, when the water surface is not parallel to the invert owing to the depth of water having been increased by the interposition of an obstruction such as a dam or weir. The term is sometimes used in a generic sense to denote all water surface profiles; or for profiles where the water is flowing at depths greater than the critical.
- Browse Related Terms: Backwater Curve, Critical slope, Equilibrium Surface Discharge, Equilibrium Time, Grout Blanket, Normal depth, Paleoflood, Sheet Flow, Steady flow, surge, Time of concentration
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The effect which a dam or other obstruction or construction has in raising the surface of the water upstream from it.
- Browse Related Terms: Apron (fore apron), Axis of dam (concrete), Backwater Effect, Berm, Check structure, Deflection, Extrados, Finger drains, Fish ladder (fishway), Forebay, Headwall, Headwater, Heel of dam, Navigation Methods, Parapet wall, Ripple, Shoulder (shell), Toe (toe of dam)
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Upstream flooding caused by downstream conditions such as channel restriction and/ or high flow in a downstream confluence stream.
- Browse Related Terms: Backwater Flooding, Contracted weir, Cross-sectional area, Diversion, Drainage Density, Energy dissipator, Ephemeral creek, Flume, Gradient, Incised stream, Instream flow requirements, Length, Mean Depth, Meander, Natural Control, Net Rainfall, Outflow Channel, Outlet channel (exit channel), Reach, Rill, River System, Scour, stream, Stream capacity, Streamflow, Thalweg, Wetted perimeter, Zero Datum
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best available control technology.
- Browse Related Terms: BACT, Crest gate (spillway gate), Drum gate, Emergency Spillway, Fleet angle, Flood Gate, Normal Water Level (Normal Pool Level), Normal Water Surface Elevation (Normal Pool Level), Outlet gate, Overwinding, Ring gate, Skimmer gate, Surcharge Capacity
Bay Area Dischargers Association.
- Browse Related Terms: ABC, ACWA, ag, BADA, Basin States, Crop subsidy, CWA, Nonterritorial communities
A flat board or plate, deflector, guide or similar device constructed or placed in flowing water to cause more uniform flow velocities, to absorb energy, and to divert, guide, or agitate the flow.
- Browse Related Terms: Baffle, Barrage, Capillary head, Flow channel, Fluctuating zone, Head Loss, Hydrologic Equation, Iowa vane, Leak, Leakage, Orifice, Primary (or Principal) Spillway, Riffle and pool complex, Storm Hydrograph, Training wall
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One of a series of upright obstructions designed to dissipate energy as in the case of a stilling basin or drop structure. A block, usually of concrete, constructed in a channel or stilling basin to dissipate the energy of water flowing at high velocity.
- Browse Related Terms: Anchor block., Artificial drains, Baffle block (dentate), Dentate., Floodwall, Horst., Ice Jam, Levee (Dike), Precast dam, River trash wall, Secondary Embankment
A 10- to 20-foot-long pipe equipped with a valve at the lower end. A bailer is used to remove slurry from the bottom or the side of a well as it is being drilled.
- Browse Related Terms: Annular space, Bailer, Bend, Branch, Butt joint (open joint), Casing, Deflect, Elongate, Fall, Field tile, Flange, Full hydraulic capacity, Gated pipe, Hanger, Haunches (haunch), import, Main, Manifold (Header), nipple, Nominal diameter, P.T, Perforated pipe, Run, Siphon, Siphonage, tile, Vertical curve
The condition in which the water pressure on the upstream and downstream sides of an object are equal (such as an emergency or regulating gate).
- Browse Related Terms: Balanced head condition, Bulkhead Gate, Clam shell gate, Differential head (unbalanced head), Displacement pump, Dry Flood proofing, Emergency gate, Gate chamber (valve chamber), Guard gate (emergency), Outlet Works, Piezometer, Regulating gate (operating gate, regulating valve), Regulating Gate (Regulating Valve), Relief valve