We can fix the problem in Florida Bay, but it will require additional freshwater flowing south from Lake Okeechobee. Florida Bay is an estuary, and estuaries exist where rivers meet the sea. In this case, Florida Bay exists where the Everglades River of Grass meets the Gulf of Mexico and the Atlantic Ocean. Without additional water from Lake Okeechobee, Florida Bay will continue to be vulnerable to local drought events, such as the summer of 2015. By restoring freshwater flow to the south of Lake Okeechobee, we improve not only conditions within the vast Everglades, but also estuarine salinity conditions in Florida Bay.
Florida Bay receives freshwater inflow from two major drainage basins, Shark River Slough and Taylor Slough (pronounced slew; see Figure 3). Taylor Slough provides the interior of Florida Bay with much-needed freshwater via a number of mangrove creeks. Shark River Slough delivers a much larger volume of freshwater to the coast, but this water needs to pass through Whitewater Bay and around Cape Sable in order to penetrate Florida Bay from the west (Figure 3). Both sloughs are essential in delivering freshwater to the bay and preventing salinity from getting too high.
Currently, Florida Bay receives less than half the freshwater from Shark and Taylor Sloughs compared to historic, pre-drainage conditions. Full implementation of projects, such as Modified Water Deliveries and C-111 South-Dade, as well as the C-111 Spreader Canal Western Project from the Comprehensive Everglades Restoration Plan (CERP), will help to improve the distribution of freshwater flow into both sloughs and prevent the siphoning of water away from Florida Bay. However, these projects do not deliver additional water to Florida Bay. Even the South Florida Water Management District’s (SFWMD) recent proposed actions to upper Taylor Slough deliver only a small net increase in freshwater flows to Florida Bay, and do not restore the bay.
CERP was authorized by Congress in 2000 and contained dozens of project components in addition to the C-111 Spreader Canal. At its core, CERP would provide for massive volumes of lost storage capacity across the Greater Everglades that would allow water managers to reduce the harmful dumping of water to the Caloosahatchee and St. Lucie rivers and re-route that flow back to the south—ultimately to Florida Bay and the Florida Keys. While there are many CERP projects yet to be constructed, there are a few key projects that will bring relief to the Caloosahatchee, the St. Lucie, the Southern Everglades and Florida Bay. No surprise, these are projects that re-connect Lake Okeechobee back to the Southern Everglades.
The Central Everglades Planning Project (CEPP), presently awaiting Congressional authorization, is a set of CERP projects bundled together to provide immediate, region-wide benefits to the Everglades. Beyond that, CERP’s Everglades Agricultural Area (EAA) Reservoir project will allow for much larger volumes of water to flow south each year. Unfortunately, this project is not considered a state priority for planning at the present time. Ultimately, as we restore the flow of freshwater to the south, we will need to ensure sufficient treatment (i.e., removal of phosphorus pollution) of that water through construction of Stormwater Treatment Areas at the southern end of the EAA, sufficient conveyance capacity through bridging of Tamiami Trail and canal backfill, and sufficient flood protection through the construction of seepage barriers and detention areas.
Figures 1 and 2: Current flow vs flow with southern storage
While we are unable to remedy the current seagrass die-off in Florida Bay, estuaries are naturally resilient. Recovery will take time, but it is anticipated. By restoring the flow of freshwater to the south, we can prevent these man-made disasters from ever occurring again. We can also improve fish habitat across the bay, as well as conditions for estuarine prey fish species essential to supporting sport fish, such as snook and spotted seatrout. If we get the water right, other species, such as Roseate spoonbills, West Indian manatees and American crocodiles, will also thrive in Florida Bay once again.
Figure 3: Map of South Florida going from the southern Everglades to the Florida Keys showing the present distribution of freshwater inflow to Florida Bay from Shark River Slough and Taylor Slough (red arrows). The C-111 spreader canal project will restore the volume, timing and distribution of flows from Taylor Slough into Florida Bay (as illustrated with blue arrows). This will result in decreased salinity over a much larger area of Florida Bay.