ORLANDO, Fla.—When the tide is right, the ink-colored water spreads like a shadow across the aquamarine Indian River Lagoon.

The dark water represents one of the most startling symptoms of what silently is killing the 156-mile lagoon, an estuary on Florida’s east coast that is among the most biologically diverse on the continent: nutrient pollution.

Nutrients are a component of fertilizers used on farm crops and front lawns. In the Indian River Lagoon the pollution has wreaked havoc, nourishing harmful algae blooms that can cloud the historically crystaline water, preventing sunlight from reaching the seagrass undulating beneath the surface. Most notably widespread seagrass losses led in 2021 to a record die-off of some 1,100 manatees in Florida, prompting wildlife agencies to resort to providing supplemental lettuce for starving manatees in the lagoon, where the majority of the deaths occurred.

The problem is among those targeted with an unprecedented $1.1 billion in federal funding aimed at revitalizing Florida’s treasured and troubled Everglades, a watershed responsible for the drinking water of more than 8 million Floridians and the subject of one of the most ambitious attempts at ecological restoration in human history. 

In the Indian River Lagoon, the money is intended to improve water quality by helping to manage polluted water flowing from area farms, said Eve Samples, executive director of Friends of the Everglades. 

“That black plume of polluted water, which comes from agricultural lands west of the lagoon,” she said, “will no longer exist. So it’s really going to help water quality in that specific section of the Indian River Lagoon.”

The money also is intended to fortify the Everglades against the rising seas and other impacts of climate change. The funding is part of the infrastructure measure President Joe Biden signed into law in November and represents the single largest investment ever in Everglades restoration, according to the White House.

The money comes at a somewhat heady time in Everglades restoration. In recent years, millions of dollars in new funding has helped jumpstart the massive federal-and-state effort, which had languished initially after the Comprehensive Everglades Restoration Plan became law in 2000. Today construction is underway on several CERP projects, and the first major project is complete: a reservoir and engineered wetlands aimed at filtering water of nutrients before the water flows into the south end of the Indian River Lagoon. 

Samples and other leaders also celebrated the completion last year of a separate project predating CERP: a major restoration of the Kissimmee River, which along with its tributaries represents the headwaters of the Everglades.  

“We are absolutely seeing more ribbon cuttings occurring and more groundbreakings,” said Kelly Cox, director of Everglades policy at Audubon Florida. “Now we get to see how (the projects are) working and how well they’re working. And from the projects that we’ve already seen come online just in the past several years, we know that Everglades restoration works, and the Kissimmee River restoration project is a good example of that. That project was done in phases, and we saw ecological returns with every single phase of that project.” 

The Everglades begin in central Florida with the Kissimmee River, which historically meandered lazily to Lake Okeechobee. The lake, a shallow depression in the land, spilled its excess water over its southern brim, forming a shallow sheet that was the river of grass. Draining large swaths of the Everglades has made modern Florida possible and left the state’s most important freshwater resource on the brink. The new federal money will fund a series of projects together aimed at improving water quality and flow and adding water storage in the Everglades.

For instance, one project relies on yet another reservoir to help improve water quality and address that shadow of dark water that occurs in the south end of the Indian River Lagoon. Another is designed to manage polluted water that flows from western Broward County and eventually ends up in Everglades National Park. The U.S. Army Corps of Engineers says that project will improve habitat for fish and wildlife, including five federally listed species. Yet another project is meant to improve water flows into Biscayne Bay.

Conspicuously missing from the list is one that is considered crucial in restoring the Everglades’ historic flow south: a large reservoir south of Lake Okeechobee in the Everglades Agricultural Area. That reservoir is aimed at alleviating harmful discharges east and west from Lake Okeechobee to fragile coastal estuaries like the Indian River Lagoon, which in recent years triggered widespread blooms of toxic algae. The omission prompted outrage among the state’s Republican leadership, including Gov. Ron DeSantis, who is widely seen as a potential presidential candidate in 2024 and has made Everglades restoration a priority of his administration. U.S. Rep. Brian Mast (R-Fla.) went as far as to characterize the omission as a “middle finger” from the Biden administration for Florida. 

The U.S. Army Corps of Engineers, the federal agency overseeing Everglades restoration, answered Mast’s criticism by saying that the corps remains committed to the reservoir, and construction is scheduled to begin this year. The Army Corps says the remaining work is projected to cost more than $3 billion, more than the $1.9 billion available in the infrastructure measure for restoration projects nationwide. 

“That’s the centerpiece of restoration,” said Steve Davis, chief science officer at the Everglades Foundation. “That’s the project that does it all, really. It takes water from Lake Okeechobee. So it reduces discharges to the east and west coasts by substantial amounts, over 50%. And it sends enormous quantities of water south.” 

While the new federal money is significant, it is not enough to fully fund CERP, which involves some 68 projects, most massive on their own. Altogether the cost is projected to be some $23 billion.

“We will see some progress, but this is a multigenerational effort,” said Samples of Friends of the Everglades. “We’re going to be waiting until my 13-year-old son is a grown man to see the results of some of these long-term infrastructure projects.”