Sanibel Island, Florida is preparing to dredge a polluted tidal slough still clogged with debris from Hurricane Ian, a $1 million project aimed at restoring the natural filter that protects Gulf seagrass beds and oyster reefs from toxic runoff.

The Sanibel River, which connects the island's interior wetlands to San Carlos Bay, has been filling with sediment for years. Hurricane Ian made it dramatically worse in 2022, dumping massive amounts of muck and organic debris into the waterway when 15-foot storm surge swept across the barrier island. The slough's capacity to treat stormwater before it reaches the Gulf has been severely compromised.

The project will remove approximately 5,000 cubic yards of accumulated muck from 1,100 feet of the slough, regrade the banks, and plant native vegetation to stabilize them. Engineers will analyze the dredged material to measure how much nitrogen and phosphorus pollution is being pulled out of the system.

Nutrient pollution from stormwater runoff has plagued Florida's coastal waters for decades, fueling algae blooms that kill seagrasses and shut down fisheries. The 2018 red tide crisis made the problem impossible to ignore. On Sanibel, where the tourism economy depends on clear water and healthy marine life, water quality is existential.

The funding comes through a congressionally directed earmark in the 2023 spending bill, part of a revived system that allows members of Congress to secure money for specific local projects outside competitive grant processes. The mechanism has gained traction for post-disaster recovery work in climate-vulnerable communities.

City officials expect the dredging to reduce storm-related flooding while improving conditions for the seagrass beds and oyster reefs that anchor the Gulf ecosystem. Construction timing has not been announced.