Sarasota County has a strong stormwater program for water quality and quantity, which has led to identifying and improving many of their stormwater issues. Knowledgeable of the need for improving water quality and the regulations brought forward by two federal/state programs of the National Pollutant Discharge Elimination System (NPDES) and the Total Maximum Daily Load (TMDL), County staff is now embarking on an effort to gather additional data on how often their stormwater ponds are discharging. The results will be educational, as these stormwater ponds are used by many developments throughout Florida.
The Sarasota County Water Planning and Regulatory group has observed that for much of the year, many wet detention ponds do not have water levels up to the control elevation. Rainfall during this condition may not result in discharge through the outfall control structure. This condition allows the pond to act as a wet retention pond, rather than a wet detention pond for that portion of the year. It has been known for many years that retaining stormwater reduces the discharge of pollutants to a higher extent than detention. Many sites do not use retention as the primary means to meet regulatory requirements since the soil conditions do not allow recovery in a short enough time to meet the storm event criteria.
Sarasota County has hired our water resources team to conduct a two year study to measure the duration of stormwater discharge occurring at 25 wet detention ponds across the County. The results from this study will then be used to improve the models used by Sarasota County in assessing compliance with the NPDES and TMDL programs. Most impaired waters in the County have, or will have, a TMDL established for one or more pollutants. There are several types of treatment systems available at a variety of costs. Once completed, the study will help Sarasota County to better understand how to evaluate the treatment of the stormwater using wet detention ponds and the amount of flow actually discharging from these ponds. This is just one way they are working to spend income from the stormwater utility wisely and get the most for it.
For more information, contact Mike Lohr, P.S.M. at [email protected].