I can not speak to the legality but from a technical standpoint if you fill in the basin with water or dirt you will eliminate the storage volume. Depending on the storage volume that is actually required, it may be possible to use a portion of the basin as a lake. However, if the basin was designed to meet water pollution standards then you would defeat its purpose by converting the basin into a lake. You will have to look at the drainage report and improvement plans to figure out what the required volume is and the actual water surface during the design event. Frequently, the outlet to the basin is designed to restrict the flow to ensure the utilization of the full volume of the basin. Another issue may be disease vectors. What requirements will the county have regarding control of mosquitoes and other disease vectors?

Good Luck,

Joseph M. Groetsch
joeg@skgaz.com