Designed to held a specific amount of water indefinitely. Sometimes called a wet pond or wet detention basin or storm water management pond, it is an artificial lake with vegetation around the perimeter, and includes a permanent pool of water in its design.
A low lying area that is designed to temporally hold an amount of water while slowly draining to another location. Sometimes called a “dry pond,” which temporarily stores water after a storm, but eventually empties out at a controlled rate to a downstream water body.
We have built many. They are for flood control when large amounts of rain could cause flash flooding.