Winter Springs is moving forward to shore up its hurricane-withstanding ability and they’ve voted to use a process that’s been available since 1986.
“We had to do something,” Mayor Kevin McCann said. “The work will continue on improving our city to face storms in the future like [Hurricane Ian].”
That was one of three storm-related items the Winter Springs City Commission mulled over during its March 27 meeting as it works toward repairing homes, city waterways and stormwater systems in the wake of a pair of hurricanes that inundated the city, with an estimated 18-27 inches of rain, varying by source, in the case of Hurricane Ian in September. The other two items were a vote to extend the development moratorium that had been in place since early January while the city researches improving stormwater management and a vote on how to pay for retaining walls and raising or demolishing homes in flood-prone areas.
But the vote for item 502 on the agenda would underpin the city’s stormwater plans as it adapts to a potential future of stronger storms like Hurricane Ian, which caused more than $100 billion in damage as it tore through the eastern U.S., making it the third-costliest weather disaster in world history, according to the Belgium-based Centre for Research on the Epidemiology of Disasters’ EM-DAT database. Only hurricanes Katrina and Harvey were more costly.
According to that same database, the amount of climate-related disasters that occurred globally nearly doubled in the period of 2000-2019 compared to the most recent 20-year span from 1980-1999. All of the top eight costliest disasters in U.S. history were hurricanes and all but one of them occurred in the last 20 years. Half of the most expensive disasters in U.S. history struck Florida.
Ian caused bridges in Central Florida to give way due to floodwaters that exceeded flow capacities that were designed for a once-in-25-years, 24-hour rain event. Winter Springs is currently being targeted by multiple audits from the state and Seminole County, one reason for which is to determine whether the city properly used money earmarked from the county to improve and rebuild bridges.
“It’s not shocking that multiple systems may have failed during Ian, because they were not designed for 18 or 19 inches of rainfall,” said Pegasus Engineers’ David Hamstra, who is consulting with the city to help redesign the city’s stormwater management. “They were designed for half that amount.”
The City Commission was mulling over four options for how to improve its stormwater standards. Commissioners voted 5-0 to adopt option 1, which was to follow the Florida Department of Transportation’s Critical Duration Analysis which takes into consideration 48 different storm durations and rainfall amounts to determine stormwater runoff potential.
Image courtesy of the City of Winter Springs.
“What DOT does and any development that ties into their DOT system, they make you look at the 2-year, the 5-year, the 25-year, 50- and 100-year storm events for different durations – one hour, two hour, four hour and etcetera,” Hamstra said.
The goal is to make sure that developable areas don’t have more runoff after development compared to before, regardless of storm size and duration. Currently the city only sets a stormwater runoff standard for a single type of storm: a 25-year storm for 24 hours of duration. The FDOT standard makes the city’s stormwater runoff control conform to 48 different storm scenarios.
“So they make you look at this battery of storms and make sure that you meet the [pre-development] versus [post-development] rate and or volume…for each frequency and for different critical durations,” he said. “They’re trying to cover the gamut, that for all the different types of storms that may be experienced, you’re not making things any worse for high-intensity, short-duration events or the big storms like a hurricane or something like that.”
Hamstra said that once a development and its required stormwater retention ponds reach their maximum holding capacity due to a storm and spill over, then the city’s stormwater systems come into play to flow the water toward Lake Jesup and beyond to the St. Johns River. But there are limits, he said.
“Understand that there are going to be events that exceed that capacity and there’s nothing we can do about it for the extreme events,” he said.
Commissioner Ted Johnson said that he wanted a middle ground where stormwater isn’t an issue but developers don’t have to dramatically reduce the amount of land they’re allowed to build on.
“I’m looking for a solution to adopt something that is not going to be a draconian event on developers, but by the same token we need to keep in mind that our task is to try and mitigate events that we’ve had most recently,” he said.
“You can stand behind the FDOT because it’s a proven design approach,” Interim City Manager Phil Hursh said.
Hamstra said that new developments may need to have slightly larger retention ponds compared to in the past, though the size increase would be less than another option the city was exploring: Option 3.
Option 3, which sets a requirement that all developments in the city have less stormwater runoff after development compared to before development, was already technically law in the city, but was not being enforced. Commissioner Rob Elliott asked Hamstra if enforcing that law would impact developers. Hamstra said that developable land would probably be reduced by 10-12% on properties if the city resumed enforcing that law.
Building the wall
The Commission also discussed how it could help residents pay for an estimated $50,000-$118,000 to build sheet-pile walls to help stop erosion and prevent stormwater damage at four properties that are alongside some of the city’s creeks. A total of four homes were identified. That cost would represent 25% of the total cost to install the walls at those houses.
Hursh said that other cities had elected to help pay for a portion of residents’ stormwater-related improvements or repairs in the past. New Smyrna Beach, he said, paid half of the 25% of the cost that the Federal Government mandates be paid locally. The federal government, through a Natural Resources Conservation Service (NRCS) grant, pays 75% of the cost.
Commissioner Victoria Colangelo suggested that the city pay for all of the 25% cost match itself. Commissioner Cade Resnick said the Commission should meet with neighborhood homeowners association representatives to determine how the city should proceed. With that suggestion, the city tabled the discussion, pending meeting with HOA officials before the next Commission meeting on Monday, April 10. That pre-meeting will be at 5:30 p.m. and is open to the public.
The city announced that it will start work to reshape a retention pond off of Mt. Laurel Drive in the Tuskawilla neighborhood on Monday, April 10. The pond was damaged when Hurricane Ian hit the area last fall.
According to the city’s press release, the construction will take place from 7 a.m. to 5 p.m., Monday through Friday and is expected to wrap up in early May.
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