08 Dec Sediment flow into lagoon must be addressed

By Guest Columnist Tom Tywford
Courtesy of the Palm Beach Post

There’s good news for the Lake Worth Lagoon. Habitat enhancement sites like Snook Islands, South Cove, and the soon-to-be-finished Tarpon Cove are helping to improve water quality. I and others have been strong advocates for creating these and similar sites for decades.

However, if we are really committed to improving the Lagoon’s water quality and marine-life habitats, we must address the sediment that is regularly delivered to the estuary during each freshwater discharge.

Where does the sediment come from? It is essentially soil and other organic material that heavy rains wash off farm fields, roads, and yards into canals.

This sediment is carried by heavy flows from Lake Okeechobee eastward through our network of canals and then is released when the spillways open.

Wind and tide distribute the fine sediment throughout the Lagoon. It gets re-suspended when the water is agitated by storms or heavy boat traffic.

This causes the water to become turbid for extended periods of time. Sea grass requires sunlight to root and thrive. Murky, turbid water prevents sunlight from reaching the seagrass beds, stunting, and smothering growth.

When this smothering condition is constantly repeated, as is the case many days, we can’t make any meaningful progress on sea grass restoration efforts.

Manatees, fish, and other estuarine dependent animals that require seagrass suffer. The only way we are going to break the vicious cycle is to get much more aggressive upstream — closer to where the sediment originates before it finds its way into the Lagoon.

The sediment is not toxic. In fact, it is nutrient rich and could benefit some landowners who border the canals. We just need to find a way to capture it.

Let’s develop a technique that dredges or pumps this sediment slurry back on land in appropriate locations throughout our network of freshwater canals.

The soupy sediment is hard to handle but I believe the technical challenges can be solved. For example, we could deploy a small fleet of mobile dredges or pumps. We must try innovative approaches like these so that we have another tool in our toolbox to improve Lagoon water quality and habitat.

If we do nothing, this problem will persist forever. All our efforts to improve the quality of the water in the Lagoon will never be fully realized.

Tom Twyford Jr. is president of the West Palm Beach Fishing Club and a board member of Sustainable Palm Beach County.