Healthy Ponds
Healthy stormwater detention ponds as shown above are easily identified by the ”No Mower Zone” of taller grass around the perimeter of the pond that is at least three feet wide and eight to fifteen inches high and the native aquatic plants in the littoral area or shallow water near the pond banks. A healthy pond will also have clearer water with little or no algal growth and a noticeable population of birds and wildlife.
Healthy stormwater detention ponds help control flooding even during major rain events like we had back in 2024 with over 17 inches of rain in 24 hours. They also offer the opportunity to reduce some of the excess nutrients like nitrogen and phosphorus before the water flows downstream to The Bay and the Gulf. That’s important because 65% of the nitrogen in the Sarasota Bay Watershed that is a principal food source for Red Tide comes from stormwater runoff.
Unfortunately, many ponds in our area still don’t have these important features and look like the picture below.
Cutting the grass all the way to the water’s edge and having no plants in the shallow water near the pond banks will soon lead to unsightly algal growth as shown below.
Algal growth occurs because the grass turf is being fertilized too near the pond and some of it is entering the water feeding the algae. Grass clippings from lawn trimming will also provide nutrients that support algal growth.Thanks to a major grant from the Charles and Margery Barancik Foundation, START is the administrator of the Healthy Pond Collaborative, a partnership with the Sarasota County NEST Program, the Manatee County Department of Natural Resources, the Suncoast Waterkeeper, the University of Florida/ IFAS Sarasota Extension and the Science and Environment Council of Southwest Florida. We can help communities deal with unsightly algae growth by introducing nutrient absorbing native plants to the afflicted pond and by adjusting irrigation and fertilizing practices. This approach will also help control algal growth without using large amounts of costly and damaging algicides like copper sulfate that not only kill algae, but also eliminate bacteria, bivalves and invertebrates that make up an important part of a healthy pond food chain.
Even more troubling than algal blooms, ponds without a “No Mower Zone” and native aquatic plants in the water will over time develop costly bank erosion as shown below.
Without a “No Mower Zone” heavy, 1,500-pound lawnmowers riding over the pond banks will begin to depress the banks initiating the erosion of soil into the pond. The lack of aquatic plants in the water will also contribute to erosion from wind and waves undercutting the banks. Erosion is troubling because the soil running into the pond reduces the capacity of the pond to hold stormwater that can lead to potential flooding. Erosion is also very expensive to fix. For example, the use of GeoTube, a balloon-like tube filled with soil that is affixed to support an eroding bank, costs $80.00 per linear foot to install. GeoWeb, a series of plastic trays filled with soil to support the bank, costs $100.00 per linear foot. START is working with several communities that have been forced to deal with neglected bank erosion that is costing over $1.5 million to repair.
START and the Healthy Pond Collaborative can help you control erosion with a cost-effective Healthy Pond Maintenance Program. The “No Mower Zone” with a bit taller grass is not a cost factor. The native aquatic plants only cost about $1.50 each and they cover a linear foot. Our $5,000 grant for native aquatic plant stock will buy over 3,300 plants and our participating communities just pay between $1.00 to $1.50 a linear foot to install them.
In the past five years, we have visited nearly 100 local communities to advise them about their ailing stormwater ponds. In 2025, we funded the purchase of over 220,000 native aquatic plants for communities that created 35.7 miles of new pond shoreline in Sarasota and Manatee Counties. If you are having trouble managing your stormwater ponds, we can help. Contact Dr. Michael Barbour at michaeltbarbour@yahoo.com.