Stormwater detention vault

They do not provide treatment to improve water quality,[2] though some are attached to a media filter bank to remove pollutants.

Underground stormwater detention allows for high volume storage of runoff in a small footprint area.

The storage vessels can be made from a variety of materials, including corrugated metal pipe, aluminum, steel, plastic, fiberglass, pre-cast or poured-in-place concrete.

In the latter case, this underground vault may be preferable to a surface detention pond if other uses are intended for the land (e.g. a pedestrian plaza or park).

In other situations, a vault is used because installing a pond might pose other problems, such as attracting unwanted waterfowl or other animals.