Urban Wetlands To Clean Polluted Storm Water
Every time it rains, storm water drains throughout South Florida pick up a slick admixture of gasoline, soot, detergent, fertilizers and other contaminants as the runoff flows through the human-dominated landscape.
Much of that toxic brew winds up in larger bodies of water, from lakes and rivers to Biscayne Bay.
To solve the problem, Yelena Katsenovich, a soil and groundwater pollution expert at Florida International University, said cities should look to nature, adding swampy shrubs and grasses wherever possible.
“Any natural [wetland] system could benefit South Florida, ” Katsenovich said during a lecture at the university’s Miami Beach Urban Studios on Tuesday.
Constructed wetlands or retention basins can help treat contaminated stormwater runoff, stripping out chemicals, metals, waste, oil, pesticides and pathogens before they enter sensitive waterways.
Some of this pollution in the water can be traced back to the early 20th century, when manmade canals, levees and dikes were created to drain water from the state’s most well known wetlands—the Everglades. The purpose was to control severe floods from storms and make the land more suitable for agriculture and development.
“All of this agriculture increased the concentration of phosphorous and it’s actually changed the ecosystem,” said Katsenovich. “And it’s become a negative factor that changes the natural system.”
During a recent trip to the University of Florida in Gainesville, Katsenovich was excited to find constructed wetlands camouflaged within the campus’ design.
The university has a wetland biochemistry laboratory and began an initiative called Stormwater Ecological Enhancement Project, or SEEP, in 1995 to enhance a retention basin located on campus. It is now a full-scale artificial wetland that improves water quality, one form of what's commonly known as a bioswale—features in the built landscape designed to remove pollution from surface water.
“Bioswale[s] could be integrated in any kind of...simple design,” said Katsenovich, “It can be some ditch that collects rain water along a parking lot or constructed along the road or a pond in the neighborhood.”
Katsenovich’s lecture, which focused on storm water contaminant remediation, was part of a Sea Level Solutions Lecture Series by FIU that is free and open to the public through April. For more information, visit their website here.