Posted on May 20, 2019
Florida – For decades, an extensive canal system dug to make way for development and farms in Collier County has altered historical water flows through the region’s two major watersheds and into its estuaries and bays.
Now, Collier officials are looking toward an ambitious plan to help restore some of the natural flowways through the county and rebalance freshwater flows into Naples and Rookery bays.
The multi-year plan, conceived in 2015, aims to improve water quality, help oysters and mangroves recover, and rehydrate about 10,000 acres known as South Belle Meade in the Picayune Strand State Forest.
At the heart of the proposal, known as the Collier County Comprehensive Watershed Improvement Plan, is an effort to send more freshwater to Rookery Bay and reduce the amount of freshwater flowing into Naples Bay.
Manmade alterations of flowways, including the Golden Gate Canal, have increased the size of the Naples Bay watershed by about 80 square miles while the Rookery Bay watershed has decreased by the same amount, Collier coastal projects manager Gary McAlpin said.
That has created problems in both watersheds, but the proposed project could encounter opposition from the owners of mostly undeveloped land that would be in the restored flowway.
Too much, too little
More water flowing into Naples Bay brings with it more nutrients, elevating nitrogen and phosphorous levels. The differences in freshwater received by each watershed also changes the salinity of the systems, McAlpin said.
That affects the survival of oysters, which help filter nutrients out of the water, improving water quality.
“It has to have the right salinity for oysters to grow,” McAlpin said. “You could plant all the oyster reefs that you want, but if the salinity of Naples Bay is not correct, oysters will not grow.”
In Rookery Bay, meanwhile, the change in the water’s makeup is detrimental to mangroves.
“Mangroves need freshwater to survive and to grow,” McAlpin said. “And so what’s happening down in Rookery Bay, there’s been die-offs in some areas in Rookery Bay because of the lack of freshwater for the mangroves.”
Furthermore, by diverting flows to the Picayune Strand State Forest county officials aim to rehydrate wetland areas, restore habitat and reduce the possibility of catastrophic wildfires. By restoring the wet season flows “to a more historical regime,” the project would also recharge the aquifer, which would help “protect the water supply for the City of Naples and Collier County,” according to a notice about a public meeting Tuesday night to discuss the project.
Reversing decades of damage
Most of Collier’s canals were dug in the 1940s and 1950s. As dredge-and-fill became the established method to meet a growing demand for waterfront housing after World War II, the canals helped create waterfront property, increased access for boating and provided fill material for buildable lots, according to an executive summary from the 2016 plan.
The widespread canal construction for urban and agricultural drainage changed the timing and quantity of freshwater flowing into coastal waters.
Groundwater levels have been lowered. Wetlands have been degraded or destroyed. Wildlife populations have been reduced. Nutrients and other pollutants have increased in coastal waters.
The watershed restoration project is estimated to cost about $32 million. It is expected to be funded through the RESTORE Act that distributes Deepwater Horizon oil spill settlement money. So far, $18 million has been committed, and the county is working to get more funding from the Florida Department of Environmental Protection, McAlpin said.
County officials are working with other agencies to see what issues there are with the project’s design and what else the county needs to do to get the necessary permits. McAlpin said the county is about six months into a permitting process that could take a couple of years.
Source: coastalnewstoday.com
