City officials address rising flood concerns
HOLMES BEACH – With heavy rainfalls becoming the norm around Anna Maria Island, residents and property owners have concerns about flooding and stormwater infrastructure, and the city’s public works staff recently held a workshop to address those questions.
Residents and business owners came to city hall on Sept. 5 with more joining online to see what the public works department, led by City Engineer Sage Kamiya, had to say.
Opening the meeting, Mayor Judy Titsworth said that she feels the city hasn’t been good at communicating what is going on with stormwater infrastructure to the community, something they’re trying to rectify with the workshop. She said the top priority for the city is to protect property values, keeping properties from flooding. The challenge, Titsworth said, is having heavy rains on top of king tides.
“Everyone has to do their part,” she said. “The city is doing its part.”
Some of her suggestions to property owners included adding flood barriers or dams to doorways, increasing permeable surface area on properties, adding stormwater infiltration where possible and lifting items on ground levels up to prevent them from being damaged by flood waters.
During a recent storm, Titsworth said she saw a manatee drinking water from a stormwater outfall and told the crowd that it’s important that infiltration trenches are built to collect rainfall in the ground rather than having it pass through untreated to local waterways where it can negatively affect wildlife.
“You’re going to be inconvenienced, you’re going to have some road closures and detours,” she said, adding that the work is necessary to reduce flooding.
Kamiya said that the infiltration trenches that have been installed all over the city aren’t necessarily meant to address capacity but to improve water quality. The infiltration trenches work by filtering rainwater through several different layers before the water flows into the water table beneath the city. He said that recent infiltration trenches installed by the city do have a capacity component to help pull more water off roads and properties faster than the older trenches.
Kamiya noted that a component of all stormwater improvements is maintenance. He said infiltration trenches need to be dug up and cleaned, removing compacted soil and other debris on a regular basis. Pipes can be enlarged, but they still need to be cleaned out and checked for breaks, leaks or other structural issues and repaired or replaced when necessary.
The city’s stormwater system was built and maintained to be a 25-year system. Kamiya said those guidelines were created by the state of Florida and handed down to the cities. Unfortunately, he said the city has experienced 200-year and 100-year storm situations just within the last few months. To simplify the math, Kamiya said the chance of a storm happening is likened to a meteorological forecast. A 100-year storm has a 1% chance of happening. Yet what the Island is seeing, he said, is an increase in the frequency of those lower percentage storms, which is causing flooding issues. In response, Kamiya said the city is constantly looking for more ways to improve resiliency and locate grant funds to improve infrastructure as quickly as possible.
The city also has engaged a contractor to do hydrodynamic modeling to help public works employees see where the biggest issues are related to stormwater and high tide events. These models help to predict the worst areas for flooding and assist with finding solutions for property owners. Staff noted that the rainfall received in Holmes Beach in August was the highest amount since 2012 in one month. Kamiya said that vulnerability assessment reports also help to determine where issues are and assist in applying for grants to fund those improvements.
“We’re doing our best to maintain the stuff that we have but then also look to the future to make things better,” Kamiya said. He added that “it breaks my heart” to see people get water in their houses, but his team is working to making things better, and it takes time to get through all the steps required for design, funding, permitting and construction.
After the presentation, residents stepped up to ask their questions.
Carol Whitmore said she understands that the infiltration trenches clean the stormwater, but she’s concerned because she’s seeing more flooding. She questioned if swales could help more than the infiltration trenches. Kamiya said that the city is looking at whether a swale or an infiltration trench is the best solution for a certain area. He added that in recent incarnations of the infiltration trenches, the staff has been experimenting with an infiltration trench that works more like a swale but that only time will tell if it works well.
Mike Roth and Commissioner Pat Morton also brought up water pumps. Kamiya said stormwater pumps are on his radar but feels that those are a longer-term solution. His concerns with installing pumps are the initial cost and then the cost and labor for maintenance. He’s waiting to receive a vulnerability assessment study to determine what the best solutions could be to flooding. Using a vac truck to clean out pipes, Kamiya said, also may help to allow more stormwater to go through outfall pipes quicker, something the city already uses but is looking at using more often to potentially reduce flooding issues.
In response to Planning Commissioner Steve Oelfke’s question, Kamiya said he feels that the city is in some ways caught up with stormwater infrastructure and in other ways he thinks they’ll never be caught up due to maintenance. He said he has an “amazing team” that is diligently working to improve the city’s stormwater infrastructure, however, once something is installed, it has to be maintained, leading to consistent work that needs to be done on the city’s part to mitigate flooding.
