Water terms starting with E

145 terms

  1. Erode To wear away or remove the land surface by wind, water, or other agents.
  2. Erosion The wearing away of land surface by wind or water, intensified by land-clearing practices related to farming, residential or industrial development, road…
  3. Erratic Boulder transported by a glacier and left behind when the ice melted.
  4. ESA See Endangered Species Act of 1973
  5. Escapement Unharvested spawning stocks that return to the streams.
  6. Escarpment A cliff or the steep slopes of a plateau edge.
  7. Essential element Any of a number of elements required by living organisms to ensure normal growth, development and maintenance.
  8. Essential Fish Habitat (EFH) Authorized by the Magnuson-Stevens Fishery Conservation and Management Act, EFH are those waters and substrate necessary to fish for spawning, breeding…
  9. Esthetics An emotional judgment about what is beautiful or pleasing.
  10. Estuary A water body where salt and fresh water meet resulting in brackish water. These areas usually have associated marshlands and are critical nursery and…
  11. Esturine waters Deepwater tidal habitats and tidal wetlands that are usually enclosed by land but have access to the ocean and are at least occasionally diluted by…
  12. Esturine Zone The area near the coastline that consists of estuaries and coastal saltwater wetlands.
  13. Eutrophic Highly fertile waters characterized by warm, nutrient-rich shallow basins.
  14. Eutrophication The natural aging process of water bodies, by siltation and organic decomposition, which reduces both water volume and oxygen levels.
  15. Evacuation The fifth of five Early Warning System components consisting of the plans, personnel, equipment, and facilities needed to move the population at risk to…
  16. Evacuation warning A public warning message that local officials would issue following declaration of Response Level III by personnel of the dam operating organization.
  17. Evaluation report (Report for Examination No. 1, first formal examination) The report of the initial SEED onsite examination.
  18. Evaporation The conversion of a liquid to a vapor (gas), usually by means of heat.
  19. Evaporation Pan A pan used to hold water during observations for the determination of the quantity of evaporation at a given location.
  20. Evaporation Rate In hydrologic terms, the quantity of water, expressed in terms of depth of liquid water, which is evaporated from a given surface per unit of time.
  21. Evaporimeter An instrument which measures the evaporation rate of water into the atmosphere.
  22. Evapotranspiration The net water loss (in vapour form) per unit area of land, both directly from the land surface, and indirectly through transpiring leaves.
  23. EWS - early warning system.
  24. Examination report A written report that documents the condition of the facility during the examination, operation and maintenance activities accomplished since the last…
  25. Excavation The action or process of excavating (to dig or remove earth). See common excavation, rock excavation, and unclassified excavation.
  26. Excess capacity Power generation capacity available on a short-term basis that exceeds the firm energy on a long-term contract offered to an electricity customer.
  27. Excess land Irrigable land, other than exempt land, owned by any landowner in excess of the maximum ownership entitlement under applicable provision of Reclamation…
  28. Excess Rain Effective rainfall in excess of infiltration capacity.
  29. Exchange capacity The capacity to exchange ions as measured by the quantity of exchangeable ions in a soil or rock.
  30. Exclusive Economic Zone (EEZ) The assertion of jurisdiction under the EEZ (3 nautical miles/3.45 statute miles to 200 nautical miles/230.
  31. Exclusive flood control capacity The reservoir capacity assigned to the sole purpose of regulating flood inflows to reduce flood damage downstream.
  32. Exclusive Flood Control Storage Capacity The space in a reservoir reserved for the sole purpose of regulating flood inflows to abate flood damage.
  33. Executive Orders Numbered consecutively, Executive Orders (EOs) are legally binding orders given by the President, acting as the head of the Executive Branch, to Federal…
  34. Exempt land Irrigation land in a district to which the acreage limitation and pricing provisions of Reclamation law do not apply.
  35. Existence value Value people place on simply knowing an area or feature continues to exist in a particular condition.
  36. Existing ground The earth's surface as it is prior to any work. See original ground surface.
  37. Exit channel. See outlet channel.
  38. Exit conference A discussion following a facility review examination involving examination team members and interested representatives of the water uses, project, and…
  39. Exotic species A non-native species that is introduced into an area.
  40. Expansion The increase in volume of a soil mass.
  41. Expansion joint A separation between adjoining parts of a concrete structure which is provided to allow small relative movements, such as those caused by temperature…
  42. Exploit Excavate in such a manner as to utilize material in a particular vein or layer, and waste or avoid surrounding material.
  43. Extirpated species A species which has become extinct in a given area.
  44. Extrados The curved upstream surface of horizontal arch elements in an arch dam. See intrados.
  45. Extrapolation Estimation of unknown values by extending or projecting from known values.