By Terry Witt – Spotlight Senior Reporter

                Williston was hit by a torrential rain event Tuesday that flooded homes, turned some streets into rivers, overwhelmed a new subdivision’s stormwater retention areas, and temporarily changed a nature park into a lake.

            In an interview Friday, City Manager Terry Bovaird said the unexpectedly powerful storm dumped 5 ½ inches of rain on Williston in just four hours, according to the Southwest Florida Water Management District (SWFWMD), better known as Swiftmud.

            Swiftmud said the storm was a once-in-a-25-year event or possibly a once in a 100-year-event. He said some residents reported their rain gauges collected between 7 and 10 inches from the storm. Bovaird said he realizes the numbers don’t mean a lot to someone whose house was flooded but it does explain the sheer volume of water that hit the city.

            “We are meeting Monday with our engineers. We’ve been looking at what happened all week and there may be are some things we can do that could help mitigate the stormwater runoff,” Bovaird said. “Stormwater runoff is nothing new in Williston unfortunately. There are some things we can do to change that.”

            Some residents on NW 7^th St. blamed the flooding on neighboring Country Lane Estates, a new 98-unit subdivision with large single-family homes built on small lots. The subdivision replaced a hardwood forest next door to Peggy O’Neill Basham Park. The forest was clearcut by Lenarr Homes for the development of the residential subdivision.

            The subdivision’s stormwater retention ponds overflowed during the heavy rain storm and poured into the park, covering it with deep stormwater that Mayor Charles Goodman said he had never seen before. He toured the area after the storm to assess the damage himself.

            “The entire park was inundated all the way up to the top of the benches, and I said, Ok I’ve been here a long time and I’ve never seen this. We had a catastrophic rain, one that I haven’t ever seen with hurricanes,” Goodman said at the city council meeting later the same day. “The length and direction of that storm was unprecedented, and I talked to Fire Chief (Lamar) Stegall and he’s been here all his life and has never seen anything on that level.”

            Was Proper Subdivision Drainage Installed?

            The heavy rain and the resulting tidal wave of stormwater flooded the home of Hailey Perry on NW 7^th St. She said she and her husband don’t live in a flood zone and didn’t have flood insurance. She asked what the city was planning to do to stop this from happening again.

            “When you have a developer that is developing land and not putting proper drainage in to allow for the streets not to flood the residents of that street – I know we’re not the first residents to deal with it since that development was brought to the city,” she said. “We love to welcome all kinds of development into the city. It makes the city more lucrative. How is the city approaching it with the developer? What are the residents, especially the residents living on that street to do, as well as to assist with this?”

            She said the flooding washed away all the ornamental plants around their home, flooding the foundation, entering the garage and other parts of the home.

            Bovaird said a meeting is planned for Monday at City Hall to continue assessing the situation with the city’s engineers, Wright-Pierce. City officials and Wright-Pierce engineers visited the new subdivision and noticed that not all the new homes were surrounded by plastic silt screens that can slow the amount of dirt and stormwater flowing off-site. He said some homes had the screens and some didn’t. Lennar officials were instructed to add a silt screen wrapping around all the new homes.

            Lennar officials were also instructed to clean the silt filters on the stormwater system that empties into the subdivision’s drainage retention ponds. The stormwater system and drainage retention ponds were designed by engineer Troy Burrell and approved by Swiftmud. The city paid Swiftmud for the evaluation and inspection of the stormwater system and the retention ponds.

            Bovaird said Swiftmud engineers told the city the agency doesn’t require developers to design stormwater retention ponds for a 100-year storm event. He said stormwater retention ponds are designed to release 50 percent of the stormwater through the pond’s bottom soils within 24 hours of a typical rain event.

            Looking for Solutions

            Bovaird said the city will return to the holding ponds when they no longer contain water to analyze the floor of the ponds to determine whether siltation is blocking the release of stormwater into the soil. He said core samples will be taken. If siltation isn’t a problem, the city may ask Swiftmud for permission to deepen the stormwater holding ponds. However, if the ponds are excavated too deep, groundwater can begin filling the pond upward through the bottom soils. There’s no guarantee Swiftmud will allow the deepening of the holding ponds.

            “We have some ideas that we think will help alleviate the problems with the runoff on 7^th St. The rainfall coming down 7^th is basically coming from every subdivision that borders 7^th from the Top of the Hill,” he said.

The city owns a piece of property near the new subdivision that could potentially be converted to an additional stormwater retention area for runoff, he said. It’s one of the solutions the city is assessing.

            He said there was also a problem with stormwater flooding a home in Cottage Cove, an older subdivision in the northwest area of Williston. He said there were apparently different standards for stormwater management at the time the subdivision was developed many years ago.

            High on City’s Radar

            Bovaird said a stormwater holding pond in Camellia Plantation also had a stormwater runoff issue in the big storm. He said the holding pond was inspected by Burrell Engineering last year and was certified by Swiftmud as meeting all of the requirements for containing stormwater runoff.

            “Once again, in a normal rain event, it does contain the stormwater runoff,” Bovaird said. “It filled up more than we would like. We think there are a couple of things we can do.”

            He said the spillway for the stormwater retention pond works properly when it overflows. The water goes to a surrounding property on the west side. “But the west side is now flooded with its own issues. There is 50 yards of flooding on the west side of the retention area that is increasing the problem,” Bovaird said.

  There was also flooding near John Henry Park. The city had obtained a $750,000 state grant for stormwater control at the park but private companies showed no interest in the work. The city was forced to obtain a companion grant that increased the amount of money available for the project to $1.2 million. A contractor has been approved. Construction is expected to begin in August, Bovaird said.

            “Until last year the city had never had a stormwater budget. Last year was the first time we put money in our budget and started looking at our stormwater issues,” Bovaird said. “I don’t know what past administrations have done to look at it but I can tell you moving forward this will be high on our radar to look at.”

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City of Williston Regular Meeting June 19, 2023; Posted June 23, 2023