NCEES Civil PE Specification V.E.: Detention/retention ponds

**Problem**

A circular detention tank with a radius of 20 feet is receiving a flow of water equal to 500 gallons per minute. If the detention time of the tank is 4 hours, determine the minimum tank height including 2 feet of freeboard at the top of the tank and 4 feet of siltation at the tank bottom.

**Select an Answer: **