answers from Chicago on. Very tiny bugs coming up the drain that hop a little are probably springtales...I goggled tiny little bugs that hop when I first encountered them and that's what came up.
Detention basin. 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.
Detention ponds help control the rate of flow by using a control device that maintains the pre-development rate of flow. The volume of the detention pond is calculated by comparing the pre- and post- development runoff volumes. The difference is the detention volume.