More than 20,000 plantings of 15 native species of littoral vegetation are now filtering the Sanibel Slough at the Jordan Marsh Water Quality Treatment Park. SC Photo by Barbara Linstrom
More than 20,000 plantings of 15 native species of littoral vegetation are now filtering the Sanibel Slough at the Jordan Marsh Water Quality Treatment Park. SC Photo by Barbara Linstrom

With construction nearly completed, the Jordan Marsh treatment park is already showing signs of improving water quality by removing nitrogen and phosphorous from the SanibelSlough.

We’re actually able to achieve…really significant reductions for a single project,” said Holly Milbrandt, deputy director of natural resources for the city of Sanibel, at the Jan. 15 council meeting. “We’re simply taking water out of the river, running it through our treatment marsh and then putting it back into the river cleaner than it was when we took it out.”

Located off of Casa Ybel Road, adjacent to the Sanibel-Captiva Conservation Foundation’s Bob Wigley Preserve, the 6-acre Jordan Marsh is in the eastern basin of the Sanibel Slough. In 2017, the Florida Department of Environmental Protection designated the slough as “impaired” and mandated reductions of 54 percent for nitrogen and 74 percent for phosphorous for the eastern section.

In this particular project, running at two cfs (cubic feet per second), we’re actually able to achieve 40 percent of that nitrogen reduction and 22 percent of the required phosphorous reduction,” said Milbrandt. “We planted over 20,000 littoral plants of more than 15 different species so it will be really exciting to watch those take over time.”

Council members lauded the project as a low-cost, highly effective and natural way of dealing with nutrient loading, which is a major cause of water quality issues throughout the region. Excess nitrogen and phosphorous get into waterways through fertilizers, wastewater and the atmosphere and feed toxic algal blooms including red tide and blue-green algae.

Controversial releases from Lake Okeechobee down the Caloosahatchee River are slated to eventually be treated in a similar way once reservoirs and filter marshes are fully funded and constructed.

There’s a pump station that brings in water from the slough, it moves through, essentially, a treatment train of a variety of littoral species of native plants before it leaves the marsh along the roadside canal on Casa Ybel Road which then flows back into the Sanibel River. So, there’s no net loss of water from the river,” she explained.

The overall cost of the Jordan Marsh project is about $810,000.

The design, engineering and permitting was about $165,000. The total construction cost was about $645,000 and we did receive some cooperative funding from the South Florida Water Management District (SFWMD) of $150,000 and are also using [$160,000] Lee County park impact fees and the rest of the funding from council,” said Milbrandt.

The project will also include interpretive panels and an observation tower.

Another goal is to educate visitors to the water quality treatment park about best management practices for improving water quality not only locally here on Sanibel but things they can do in their own backyard as well,” said Milbrandt.

James Evans, director of natural resources, thanked Milbrandt for managing the project and keeping it on time.

We anticipate the ribbon cutting will be sometime in mid to late February,” said Evans.

In his regular water quality update, Evans reported that releases from Lake Okeechobee remain at adequate levels for the dry season to keep salinity levels in the positive range for the health of tapegrass in the upper estuary.

In his red tide update, Evans said in the past several weeks there hadn’t been any impacts associated with red tide on Sanibel.

However, the Fish and Wildlife Conservation Commission’s monitoring is reporting high concentrations of red tide in Sarasota and off the coast of Marco Island. And, they’re also, as of today reporting low concentrations off the coast of Key West on the inside of Florida Bay,” he said. “Water temperatures are still in the suitable range for red tide development, so we’ll keep our eyes peeled.”

Council member Chauncey Goss asked if essential red tide data from NOAA had been impacted by the shutdown.

We are getting some data from NOAA but it’s not like our normal weekly reports – it’s not as detailed. But, NOAA’s satellite images are still available,” Evans said.

Follow water quality monitoring by the city at