Sarasota County’s stormwater division has plans for a drainage project that would do more than just alleviate major flooding on Higel Avenue and Reid Street.
The project would replace an open drainage ditch on Ocean Avenue with a buried pipe while filtering pollutants and debris from stormwater.
Replacing the unsightly “mosquito ditch” on Ocean Blvd. and adding an installed vegetated bioswale would also result in a more aesthetically-pleasing ‘gateway’ into Siesta Village. The Ocean/Higel Drainage Improvements project would also alleviate the hazard of having a ditch right off the pavement.
The project, estimated to cost a maximum of $412,000, would be funded by the county as a stormwater maintenance project.
The project is the result of several years of planning.
In September, 2013, after some intense rains, a drainage pond called Banan Lake, on the south side of Ocean Blvd, flooded. “The area around Banan Lake flooded significantly,” said Ben Quartermaine, Sarasota County Stormwater Engineering & Operations Manager. “News 40 did a live shot along Reid Street, where reporter was standing in thigh deep water. Significant road flooding caused roads to be impassable.”
The county’s stormwater division then asked this question: “How we could improve drainage in this area?”
The current drainage system isn’t working. It is comprised of an ad-hoc network of drainage canals and ponds that is no longer functioning.
Banan Lake and Fiddler’s Bayou —located north of Ocean Blvd. — are two drainage ponds connected by ditches. For years, this system drained rain water out into the Gulf, passing through Fiddler’s Bayou.
“As water in Lake Banan got really high, it flowed to Ocean Boulevard and as the ditch [on Ocean] got high, the water flowed into Fiddler’s Bayou. As the Bayou got high, the stormwater drained into the Gulf,” Quartermaine explained.
Yet one reason why this system is no longer working is the accumulation of naturally accreted dunes to the north of Fiddler’s Bayou that are blocking the runoff area where the bayou historically drained.
As a result, excess rainwater from Lake Banan that has no where to go floods across Higel, eventually emptying into the Grand Canal.
In addition, during summer, there is often standing water in the ditch along Ocean Blvd. The drainage ditch is the kind that’s often referred to as a “mosquito ditch.” This type of canal has earned the name for good reason. During recent survey work, county employees have found evidence of breeding mosquitos, including larvae, in the ditch that runs parallel to Ocean Blvd.
“We started looking for alternatives,” Quartermaine said. “How could we improve the drainage in this area and also allow the dunes to protect the homes and that area.”
The project would improve the existing drainage system along Ocean. Stretching from the curve on Ocean to the intersection of Higel, crews would install a new, buried pipe. The pipe would eliminate the presence of open standing water.
Above the buried pipe, a vegetated bioswale would filter some of the pollutants found in rainwater, such as nitrogen.
Another buried pipe, along Higel, would direct rainwater south to Lotus Lane. From there, the county would enlarge a pipe under Lotus that would allow stormwater to drain into the Grand Canal.
The project is designed to hydrologically connect Banan Lake and Fiddler’s Bayou so the two water bodies have time to percolate naturally into the ground after rain events. Excess water would drain efficiently to the south, into the Grand Canal.
But the water that flows into Grand Canal would be cleaner than water that currently drains into the canal. That’s because a major aspect of the project would work to improve stormwater quality. “We would solve the drainage issue in this area, and also look to do some drainage treatment” of stormwater, Quartermaine said.
At Ocean and Higel, crews would install a stormwater box to collect sediment —including dirt collected along the road. Downstream, the county would install a strainer that would trap any debris or trash floating in the water. “That would be located as far downstream as we can, so it has the greatest [filtering] effect,” Quartermaine said.
On a regular maintenance schedule, the county would vacuum and remove debris from the strainer. “The county has a big vacuum truck that has a route and sucks out that sediment on a regular basis,” Quartermaine said.
The county project requires a permit from South West Florida Water Management District (SWFWMD). As part of the county’s conversations with SWFWMD, the district and county agreed the county needs to reach out to residents before a permit is issued. “We want to make sure the neighborhood, Siesta Key, understands the project, and we have buy in before the district moves forward with permitting,” Quartermaine told the News Leader.
To that end, Quartermaine and county staff will present plans for the project at both the upcoming Siesta Key Association meeting December 3, 4:30 PM at St. Boniface Church Room F and Siesta Key Village Association meetings.