Editor’s Note: On August 31, Obama announced that the federal government would commit $30 million to help spur restoration efforts at the Salton Sea. And another $10 million will likely come from the Water Funder Initiative, a group of leading philanthropic foundations.

Located in Riverside and Imperial counties, about 150 miles (240km) southeast of Los Angeles in the desert, the Salton Sea is a 360-square-mile (930-square-km) lake, the largest by area in California. But that status is under threat, as the lake has been shrinking for years, exposing the dry lakebed and creating dust that has hurt the air quality for local residents, while taking away critical wetland habitat for thousands of birds.

Now conditions are expected to deteriorate at a rapid clip when it stops receiving Colorado River water as part of an earlier agreement. California made plans to compensate for the impacts with major mitigation measures, but aside from a couple of small projects that finally got funding approval this June, little progress has been made.

An Unintentionally Created but Now Essential Lake

In its modern incarnation, the Salton Sea, which was the site of an ancient lakebed, was created in 1905 when the turbulent Colorado River breached a levee and for two years flooded what was meant to be an irrigation diversion channel for water flow to farms.

In its heyday in the 1960s, the Salton Sea was a thriving recreational destination for fishermen, and more than 300 species of birds flocked to the wetlands it provided along the Pacific Flyway.

The sea is fed by water from local rivers, creeks, storm runoff, agricultural runoff and wastewater discharges.

But because there’s no natural outlet, water continually evaporates, increasing the salinity of the remaining water and hurting the fish population that feeds the migrating birds. Salinity levels are close to 60 parts per thousand in the lake and climbing. The Pacific Ocean, by comparison, is 35 parts per thousand.

Now a more serious problem will further compromise the lake and the health of those in the region.

Colorado River Water Overdraft Woes

California had been overdrawing its allotment of Colorado River water for years, but with surplus shifting to shortage among the six other states that share the water, a change was necessary.

In 2003, California was asked to come up with ways to reduce its dependence on the river. As part of the Quantification Settlement Agreement (QSA), the Imperial Irrigation District (IID), which gets a significant annual allotment of the river water for the region’s farm sector, agreed to reduce water use by employing irrigation efficiencies (and for some time, fallowing land). Those savings would be transferred to the San Diego Water Authority, in the largest farm-to-city sale of its kind in the U.S. The deal is good for 35–75 years and deliveries will reach 200,000 acre-feet (about 247 million cubic meters) a year.

But with IID farmers becoming more water efficient, that means less runoff to feed the Salton Sea. So an agreement was made for IID to transfer its water savings to the Salton Sea until the end of 2017, at which point the state would assume responsibility for mitigation of the diminishing lake.

But the state’s mitigation plans stalled and now the 2017 deadline is around the corner.

To compound the problem, California, which has senior rights to Colorado River water among the states that share the water, has offered recently to voluntarily give up about 8 percent of the water to keep Lake Mead from dipping too low and threatening water supplies to the Southwestern U.S., and the Hoover Dam’s hydroelectric capacity.

“The Colorado River agreement is important and it affects water shortages for millions of people,” said Mike Lynes, director of public policy for Audubon California. “What we are saying is while it’s important, it has to include solutions for the Salton Sea as well.”

Audubon thinks this most recent agreement simply trades one set of problems for another, by neglecting the dire needs of the Salton Sea.

“What we want from the agreement is that it should not create a circumstance where less water goes to the Salton Sea without a budget and firm plan to address impact. We don’t want a repeat of the 2003 QSA,” Lynes said.

The state’s original mitigation plan had a big budget of $9 billion, but circumstances changed with the Great Recession of 2007 onward and the plan had to be scaled back. Smaller projects were planned with much ado, but they stalled until this June, when the state legislature approved $80.5 million to actually begin construction on the Red Hill Bay Restoration Project and other measures.

Lynes has a dim view on the current status of mitigation measures and the long delays.

“We are looking at playa (lakebed) exposure of 75,000 acres [30,300 hectares], and up to 100,000 acres [40,500 hectares] over the next 30 years or so as the Salton Sea continues to shrink,” he said. “Right now there are no projects on the ground to create new habitat or control dust.”

In a 2014 report, the global water think-tank the Pacific Institute said inaction in addressing the Salton Sea’s problems could end up costing as much as $70 billion over 30 years.

A top concern is the effects on air quality from dust.

“Air quality is an issue in the region, because of particulate matter from dust,” said Roya Bahreini, an atmospheric scientist with the University of California, Riverside, who has been studying the area’s air quality.

While the water levels in the sea won’t go back to previous levels, she says it’s important to install dust-control measures, and that the state could borrow pointers from other places such as Owens Lake, where mitigation measures – for instance, planting certain grasses – have worked to reduce dust.

Dust emissions from the dried-up lakebed have so far contributed 25 percent of the PM10, a kind of particulate matter, found in the region’s air by her calculations, and she expects this will increase unless mitigation measures are put in place soon.

“Smaller projects are definitely a good idea, but these projects are taking too long to get done and we need to be thinking of the next wave of projects that need to be implemented,” Lynes said. “The sea is going to be receding extremely fast, so projects to address impacts need to be sped up.”