As part of the Department of the Army, the Corps has responsibilities in civil and military areas. In civil works, the USACE has authority for approval of dredge and fill permits in navigable waters and tributaries thereof; the USACE enforces wetlands regulations, and constructs and operates a variety of water resources projects, mostly notably levee, dams and locks.
- Browse Related Terms: Alert Stage, Author's signature, Community cohesion, disaster, Emergency, National Response Center (NRC), National Response Team (NRT), On-scene coordinator (OSC), Regional Response Team (RRT), U.S. Army Corps of Engineers (USACE)
The Federal agency whose mandate was to reclaim the arid west of the United States. Operating in 17 western states, this agency builds, operates and maintains a variety of irrigation, power, and flood control projects.
- Browse Related Terms: Associated facility, Association of Boards of Certification (ABC), Beneficiary, Non-reimbursable, Oil spill contingency fund, Onsite Coordinator (OSC), Reimbursable, Reserved works, Transferred works, U.S. Bureau of Reclamation (USBR), Water user
The USGS serves the Nation by providing reliable scientific information to describe and understand the earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life. The agency that monitors streamflows, river hydrology, and seismic activity.
The Federal Agency chartered in 1879 by congress to classify public lands, and to examine the geologic structure, mineral resources, and products of the national domain. As part of its mission, the USGS provides information and data on the Nation's rivers and streams that are useful for mitigation of hazards associated with floods and droughts.
- Browse Related Terms: Advisory Council on Historic Preservation (ACHP), ALC #, Benchmark (BM), Executive Orders, FEMA, Forest Service (FS), Jurisdiction, List of National System MPAs, Management/Managing Agency or Authority, Marine Protected Areas (MPA) Inventory, National Institute for Occupational Safety and Health (NIOSH), Occupational Safety and Health Act of 1970 (OSHA), Primacy, Proratable water, Purveyor, Reportable quantities, U.S. Geological Survey (USGS), Water purveyor, Water transfers
The load per unit of area required to produce failure by rupture of a supporting soil or rock mass.
- Browse Related Terms: Allowable bearing capacity, Arching, At-rest earth pressure, Capillary Potential, Coefficient of consolidation, Effective force, Flow failure, Flow slide, Foundation material (foundation soil), Foundation surface, Internal vibration, Landslide, Peat, Pore pressure, Shear zone, Slough, Ultimate bearing capacity, Void
See differential head.
- Browse Related Terms: Aggradation, Contour map, Degradation, Grade (pitch), Head, profile, slope, Sluice, Static head, Topographic map, Unbalanced head.
Electric service is traditionally provided on a bundled basis, meaning that generation, transmission, and distribution services are provided as a single package. By unbundling, the packaged offering of the various services that make up traditional utility service are separated into discreet, separately-priced components. An example would be selling electric power distribution as a separate service without including costs associated with power generation or transmission services. Unbundling could allow the customer to select a different supplier or source for each of the components required to obtain a product or service.
- Browse Related Terms: access charge, Commercial river trip, Direct access, Distribution, Grid operator, Unbundling (functional unbundling), Utility, Wheeling, Wholesale power market
Describes situations where potential outcomes cannot be estimated based on historical events.
- Browse Related Terms: Annualized loss of life, APE, Decomposition, Effective peak ground acceleration, Esthetics, Failure potential assessment, Hazardous materials, Intangible Flood Damage, Job hazard analysis (JHA), Random earthquake, Risk, Uncertainty, Velocity Zones
Excavation paid for at a fixed price per yard, regardless of whether it is common or rock excavation.
- Browse Related Terms: Common excavation, cut, Cutting, Earth lining, Excavation, Foundation, Gravel blanket, Grubbing, Haul distance, Lift, Overexcavation, Overhaul, PASS, Pay formation, Spoil, Stripping, Swell, Through cut, Unclassified excavation
Material used in refilling an excavation without the material being compacted. See backfill.
- 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
An aquifer containing water that is not under pressure; the water level in a well is the same as the water table outside the well. An aquifer that discharges and recharges with an upper surface that is the water table.
Also listed in:
- All > Science > Energy > Renewable Energy > Solar Energy
A break or gap in the geologic record where rock layers were eroded or never deposited.
- Browse Related Terms: Anticline, Aquifer, Bedding plane, Dip, Flatirons, Impinge, Monocline, Seam, Strata (stratum), Stratigraphy, Subbase, Syncline, Thermal stratification, Unconformity
A current below the upper currents or surface of a fluid body.
- Browse Related Terms: Abrasion, Albedo, Erode, Fountainhead, Isobath, MS connectors, Piezometric surface, Reflectivity, Surface Impoundment, Unconfined aquifer, Undercurrent, Wetland
Also listed in:
The lateral motion of water through the upper layers until it enters a stream channel. This usually takes longer to reach stream channels than runoff. This also called subsurface storm flow.
Also listed in:
- All > Science > Energy > Renewable Energy > Solar Energy
- All > Science > Weather
- All > Technology > Telecommunications
Vegetation underneath the trees.
Also listed in:
- All > Science > Energy > Renewable Energy
- All > Science > Energy > Renewable Energy > Solar Energy
Any project, activity, or program that could change the character or use of historic properties.
- Browse Related Terms: ALP, BCPA, Cost allocation, Design Flood, Extrapolation, Impact, Irrigable area not for service, overhang, Recreational benefit, Rehabilitation, Spills, Undertaking
A soil sample that has been obtained by methods in which every precaution has been taken to minimize disturbance to the sample.
- Browse Related Terms: compaction, Dumped, Jetting, Ponding (or flooding), Puddle, Puddling, Rolling, Saturation (and internal vibration), Shrinkage, Sluicing, Subgrade, Surface vibration, Tamp, Tamper, Tamping, Tamping roller, Undisturbed sample, Unified Soil Classification System
A method of grouping and describing soils according to their engineering properties.
- Browse Related Terms: compaction, Dumped, Jetting, Ponding (or flooding), Puddle, Puddling, Rolling, Saturation (and internal vibration), Shrinkage, Sluicing, Subgrade, Surface vibration, Tamp, Tamper, Tamping, Tamping roller, Undisturbed sample, Unified Soil Classification System
Open channel flow where the depth and discharge remain constant with respect to space. Also, the velocity at a given depth is the same everywhere.
- Browse Related Terms: Critical Depth, Critical flow, Critical velocity, Froude number, Gage, Non-uniform flow, Price Current Meter, Rapid flow, Spillway chute, Subcritical flow, Supercritical flow, Tranquil flow, Uniform flow, Water hammer (hydraulic transient)
The direct runoff hydrograph resulting from a unit depth of excess rainfall produced by a storm of uniform intensity and specified duration. A hydrograph with a volume of 1 inch of runoff resulting from a storm of a specified duration and areal distribution. Hydrographs from other storms of the same duration and distribution are assumed to have the same time base but with ordinates of flow in proportion to the runoff volumes.
- 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
Also listed in:
The discharge hydrograph from one inch of surface runoff distributed uniformly over the entire basin for a given time period.
- Browse Related Terms: Basin, Cistern, Detention Basins, Detention dam, Hydrograph Separation, Inches of Runoff, Outlet capacity, Unit Hydrograph (or Unitgraph), Unit Hydrograph Duration, Unit Hydrograph Theory