Environment

Water managers take steps to improve South Florida bays

On Thursday, South Florida water managers approved a $5.4 million construction contract to complete work on canals, levees and pumps that will help bring more freshwater to Florida Bay, where high salinity triggered a massive seagrass die-off in 2015. Seagrass provides habitat for shellfish and other marine life critical to wildlife.
On Thursday, South Florida water managers approved a $5.4 million construction contract to complete work on canals, levees and pumps that will help bring more freshwater to Florida Bay, where high salinity triggered a massive seagrass die-off in 2015. Seagrass provides habitat for shellfish and other marine life critical to wildlife. MIAMI HERALD Staff

Biscayne Bay and Florida Bay, the two massive and ailing shallow bays that draw tourists and dollars from around the globe, both got a little first aid Thursday.

South Florida water managers signed off on two measures designed to bring more freshwater to both. While they represent only a fraction of what’s ultimately needed, the water and work covered by the projects is expected to begin repairing a fragment of wetlands that once fringed Biscayne Bay and reduce salty conditions in Florida Bay that wiped out nearly 25 square miles of seagrass in 2015. And both projects, water managers noted, cost a fraction of the larger comprehensive Everglades restoration plan that is still years from completion.

It’s going to be a small step with very big results.

South Florida Water Management District Executive Director Pete Antonacci

“It’s going to be a small step with very big results,” South Florida Water Management District Executive Director Pete Antonacci said Thursday after the district board approved a $5.4 million construction contract for the Florida Bay project.

The work was originally suggested as an emergency fix to deal with the worsening seagrass die-off after a regional drought set off a spike in salinity. A winter of record rain followed, flooding the sprawling water conservation area just north of Everglades National Park, which water managers seized on as a potential fix. The bay receives much of its water from rainfall, but historically also received about 42 percent of freshwater from the Everglades — mainly through Taylor Slough — which helped the unique quilt of basins survive extra-dry years.

Audubon Florida Biologist Jerry Lorenz says a massive seagrass die-off shows why Florida's Everglades need to be fixed.

Using existing canals and pumps, the district began diverting more water into the Florida Bay last year. The effort worked so well, the district decided to make the changes permanent. With additional plugs, rebuilt levees and larger pumps, district officials said last year the bay should receive about 6.5 billion more gallons of water a year, about a sixth of what the 2000 Comprehensive Everglades Restoration Plan called for.

6.5 billion gallonsThe yearly increase in the amount of water going to Florida Bay, about a sixth of what a 2000 restoration plan says is needed.

The fixes are “not the silver bullet, but it’s something that can help keep [the bay] on life support until further restoration efforts are online,” said Ernie Marks, the district’s director of Everglades policy and coordination.

The second project represents the much smaller, first phase of a larger project designed to undo the damage from decades of drainage in 11,300 acres of wetlands, about half of the marshes that fringed the western edge of Biscayne Bay. On Thursday, the board approved steps to purchase about 622 acres of privately owned land, a significant hurdle in completing the project that will include more than 3,700 acres. Work completed so far, which helped steer water into wetlands around the Deering Estate, has helped kill off upland plants and trees to clear the way for sawgrass and lowland sedges to return.

While the water has not been enough to lower salinity in Biscayne Bay, according to the 2016 National Academy of Sciences review of restoration efforts, key features of the marsh are back: periphyton sprout, an important source of food, along with more birds, fish, amphibians and other wildlife.

The district still needs to work out a deal with Miami-Dade County and Florida Power & Light for another 752 acres, but Marks said buying the private land stood as a bigger obstacle. The district hopes to buy the land at an appraised value of $2.3 million. If negotiations fail, the district plans to take the land by eminent domain.

The second, larger phase of the project is not slated to begin until at least 2021 and even now faces questions over whether the county can provide enough water for it to succeed. Marks said the district plans to take a closer look at those issues as the date nears.

“As we get closer,” he said, “we’ll have a better idea of what those challenges will be.”

The University of Miami is conducting a study in Biscayne Bay to better understand how trash, sewage, oil, and harmful algae blooms get transported through South Florida waters by wind and ocean currents.

Follow Jenny Staletovich on Twitter @jenstaletovich

  Comments