Technical Manual: Conduits through Embankment Dams (FEMA 484)

GlossaryDrawdown (FEMA, 2004): The difference between a water level and a lower waterlevel in a reservoir within a particular time. Used as a verb, it is the lowering of thewater surface.Drilling: The process of penetrating earth and/or rock formations.Dry density (ASTM D 653, 2002): The mass of solid particles per the total volumeof soil or rock.Dry spot (ASTM F 1743, 1996): An area of fabric of finished CIPP that is deficientor devoid of resin.Dry unit weight (ASTM D 653, 2002): The weight of soil or rock solids per unitof total volume of soil or rock mass.Durability (ACI, 2000): The ability of a material to resist weathering, chemicalattack, abrasion, and other conditions of service.Ductile iron pipe: See Pipe, ductile iron.Earthfill dam: See Dam, earthfill.Earthquake (FEMA, 2004): A sudden motion or trembling in the earth caused bythe abrupt release of accumulated stress along a fault.Electrical resistivity: A geophysical mapping method based on the principle thatthe distribution of an applied electrical potential (voltage) in the ground depends onthe composition and density of surrounding soils and rocks.Embankment dam: See Dam, embankment.Emergency (FEMA, 2004): A condition that develops unexpectedly, whichendangers the structural integrity of an embankment dam and/or downstreamhuman life or property, and requires immediate action.Emergency Action Plan (EAP) (FEMA, 2004): A plan of action to be taken toreduce the potential for property damage and loss of life in an area affected by anembankment dam failure or large flood.Emergency classification: The act of classifying an emergency at an embankmentdam, to determine the severity of the emergency condition and the proper responseto prevent a dam failure, and to reduce loss of life and property damage, should thedam fail.399