Slide 107 of 119
Notes:
Dry detention ponds are similar in design to dry extended detention ponds, except that they do not incorporate features to improve water quality. In particular, these practices do not detain stormwater from small flow events. Therefore, detention ponds provide almost no pollutant removal. However, dry ponds can help to meet flood control, and sometimes channel protection, objectives in a watershed.
Dry extended detention ponds (shown in this slide schematic) are basins whose outlets have been designed to detain the stormwater runoff from a water quality design storm for some minimum time (e.g., 24 hours) to allow particles and associated pollutants to settle. Unlike wet ponds, these facilities do not have a large permanent pool. These facilities tend to clog and be unattractive without any type of micropool at the location of the riser. They can also be used to provide flood control by including additional flood detention storage.