Before revision: A detention basin in Sterling, Virginia, in the United States A detention basin or retarding basin is an excavated area installed on, or adjacent to, tributaries of rivers, streams, lakes or bays to protect against flooding and, in some cases, downstream erosion by storing water for a limited period of time.
After revision: File:2018-11-16 06 54 56 View of the sky and clouds just before sunrise from a snow-covered field and water-filled detention basin along Old Ox Road in the Dulles section of Sterling, Loudoun County, detention basin in Sterling, Virginia, in the United States A detention basin or retarding basin is an excavated area installed on, or adjacent to, tributaries of rivers, streams, lakes or bays to protect against flooding and, in some cases, downstream erosion by storing water for a limited period of time.