Old-Fashioned Swales Better at Removing Stormwater Pollutants, Study Finds

Study Accounts for Pollutant Removal by Swales

It's not sexy like a shiny, new capital project but the "Old Florida" swales in your neighborhoods are reducing pollutant loads in a way that you could never afford to retrofit. A recent study by Sarasota County and the Southwest Florida Water Management District found nitrogen loading to be 93% less in residential areas served by swales as compared to those with curb and gutter drainage. Infiltration is a key to swale reductions as it is with Low Impact Development.

Communities struggling with pollutant loading regulations may find that areas developed before flood control ponds are enjoying nitrogen removal from grassy swales that was not accounted for in the models. Sarasota County has mapped 50,000 acres of swale-drained land so far. That would equate to billions of dollars of ponds if retrofits were mandated.

Take a fresh look at the swales in your town and bring a new perspective to your next permit meeting. Ask the regulators to review this study. At the very least, having a map of swales will change your plans about where to locate your next project. The study "EMC Monitoring in Support of Pollutant Load Modeling" is in the Digital Library under keywords "swale study."

A healthy bay is everybody's business. Finding a cost-effective way to achieve it may be right in your backyard.

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