Keeping stormwater as clean as possible a big key to improving overall water quality, Siesta Key Association members hear

Coordinator of county program talks about steps homeowners and others should take

A graphic shows the results of heavy rainfall on Siesta Key. Image courtesy Sarasota County

In an average year, Sarasota County gets about 53 inches of rain, and on occasion, it all seems to fall “at one time,” the coordinator of Sarasota County’s Neighborhood Environmental Stewardship Team (NEST) told members of the Siesta Key Association during their June 6 regular meeting.

Additionally, the runoff produced by that rain in communities built before 1984 “goes right to the bay,” Mollie Holland pointed out. “It’s not treated in any way, shape or form.”

From U.S. 41 west, she told the approximately 30 people present, no stormwater management areas exist. That is all the more reason people need to keep the runoff from rain — the stormwater — as clean as possible, she stressed. Sometimes, from areas with no stormwater systems, Holland said, it takes only minutes for the runoff to reach the watershed; at most, 12 hours.

“Anything that is in your yard will be in the bay,” she added. “It’s just a matter of time.”

Holland also encouraged those present to be “kinder, gentler to your yards.”

Stormwater can pick up pesticides and fertilizers that have not had time to be absorbed by lawns, she noted. It also can transport pet waste, which carries bacteria as well as nutrients, she said. Further, dry and decaying leaves and grass clippings are sources of nutrients that end up in the waterways.

Before so much residential development was created in Sarasota County, Holland explained, wetlands were abundant. “Mother Nature had it all figured out.” Nutrients that feed red tide, for example, could be filtered out before they reached the waterways and ended up in the bay, she said.

A graphic explains how pollutants end up in stormwater and then waterways. Image courtesy Sarasota County

Even with modern stormwater systems having been provided throughout the county, Holland continued, “If the tide’s up and we get a lot of rain,” those systems can be overwhelmed.

Stormwater measures the county has created, she explained, have been designed for a 100-year storm event. However, 8 inches of rain in 24 hours is considered a 100-year level of rain, she added. “We’ve had that before.”

Along with the issue of nutrients being transported to the bay, she said, stormwater deposition of sand in the bay can cloud the water and prevent seagrasses from getting the sunlight they need to survive and thrive. Stormwater also can reduce the level of the bay’s salinity, Holland noted, which can have a negative impact on oysters and fish, for examples, which need a certain amount of salinity to exist. “We lose oysters because our water’s too fresh.”

Another issue is “thermal pollution,” she pointed out.

In a slide she showed the audience, steam was rising from a road after rainfall. “Imagine that hot water going into the bay,” she said.

If the bay is too hot, she continued, fish and other creatures cannot breed. Additionally, the hot water can make them sick, she pointed out.

This graphic offers details about thermal pollution. Image courtesy Sarasota County

Furthermore, Holland stressed, “The warmer the water is, the more likely it is to [facilitate] algal blooms.”

Sarasota County staff contracts with a third party to monitor about 100 water bodies each month, she continued. The company tests for fecal coliform bacteria and three forms of nitrogen, for examples, Holland said. “Why do we monitor? For completely selfish reasons: for public safety and health.”

She then joked, “We want to see where we can spend your money to do the best good” in improving water quality.

For one example, Holland noted, the county helped the SKA install stands with pet-waste bags at various locations on the Key.

Robert Luckner, a member of the SKA’s Environmental Committee, pointed out that the organization distributes about 40,000 of the bags each year, for which it pays. It has about 10 of the stands left, he added.

The data produced by the monitoring also is necessary when staff is applying for grants from the federal government and other large organizations, Holland explained. “We have to show that there’s a need [for funding assistance].” Staff members can document issues, she said, and then propose plans for mitigating those problems.

A graphic shows details about the water monitoring conducted for Sarasota County. Image courtesy Sarasota County

Holland also reminded the audience members that a Sarasota County ordinance restricts the use of fertilizers with nitrogen and phosphorus from June 1 through Sept. 30, which typically is the rainiest part of the year in Southwest Florida. The rest of the year, she continued, county regulations forbid the use of fertilizers within 10 feet of a water body, including ditches and swales.

Holland left brochures explaining how to read fertilizer labels and how to determine if a yard is healthy.

Most people with agricultural operations will not fertilize soil until they have tested it, she pointed out.

Any member of the public can get soil samples from a yard tested for free at the University of Florida/Institute of Food and Agricultural Sciences (UF/IFAS) Extension Program in Sarasota County, which is located at Twin Lakes Park at 6700 Clark Road in Sarasota, Holland said.

UF/IFAS staff will ask a person to dig down a few inches in the person’s yard, she continued, and then get a couple of teaspoons of soil. After the staff members receive the results of the testing on that soil sample, she added, they will let the homeowner know whether the yard needs specific minerals or nutrients.

She noted, for example, that if grass turns yellow in the summer, that means it needs minor elements, such as iron — not nutrients.

Red tide impacts

Mollie Holland addresses SKA members on June 6. Rachel Hackney photo

Turning to the subject of red tide, Holland responded to a question about why the Florida Fish and Wildlife Conservation Commission (FWC) has implemented a catch-and-release rule for trout. “They did that as a direct result of red tide. … The population [of that fish species] did not come back from red tide.”

Then Holland talked about diving approximately 3,000 feet offshore, in depths of about 20 to 30 feet, in August 2018 to check on various structures. “There was nothing out there.”

The first week of that month last year was when Sarasota County staff began documenting the intensification of fish kills, especially, but also deaths of other sea creatures, as the red tide bloom worsened and moved close to the shoreline.

As a contrast, Holland told the SKA members, when she dove in the same area in May 2018, she found an abundance of fish, corals, sea urchins and juvenile oysters. “Everything was completely gone in August.”

“A lot of our data, our guidance, was that it was going to be years” before the sea life returned after the devastation of red tide, she continued. Yet, the previous week, she said, she and colleagues were diving in the same general area as last August, and they saw corals again. “The fish are back, and sea urchins.”