NOTICE: has been archived.

The archive will be available at for approximately one year (through September 2020). If you use or are responsible for content here that is not yet available elsewhere, please contact the PWD Digital Team.

Glossary beginning with D

terms for which definitions are available


a man-made barrier, together with its appurtenant works, constructed for the purpose of impounding or storing water or another fluid or semifluid


Pennsylvania Department of Conservation and Natural Resources

defective lateral

a plumbing problem in which a lateral pipe is damaged, potentially leading to sanitary waste in a storm sewer and the receiving water body


the volume of runoff that is captured and released into the waters of this Commonwealth at a controlled rate

detention basin

an impoundment designed to collect and retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate; designed to drain completely soon after a rainfall event and become dry until the next rainfall event


any human-induced change to improved or unimproved real estate, whether public or private, including, but not limited to, land development, construction, installation, or expansion of a building or other structure, land division, street construction, and site alteration such as embankments, dredging, grubbing, grading, paving, parking or storage facilities, excavation, filling, stockpiling, or clearing


flow; a measure of the volume of water flowing through a defined area in a given time. Discharge is often abbreviated as Q, and measured in cubic feet per second (cfs)

drainage area

the area of land that drains to a particular body of water or site on a waterbody; also see 'catchment'