SALT LAKE CITY (AP) – The largest natural lake west of the Mississippi is shrinking past its lowest levels in recorded history, raising fears about toxic dust, ecological collapse and economic consequences. But the Great Salt Lake may have some new allies as conservative lawmakers plan to step in.

The new burst of energy from the state government comes after lake levels recently hit a low point during a regional megadrought. Water has been diverted away from the lake for years, though, to supply homes and crops in Utah. The nation’s fastest-growing state is also one of the driest, with some of the highest domestic water use.

This year could see big investment in the lake that has long been an afterthought, with Governor Spencer Cox proposing spending $46 million and the powerful House speaker throwing his weight behind the issue. But some worry that the ideas advancing so far at the state Legislature do not go far enough to halt the slow-motion ecological disaster.

One proposal would tackle water use in homes and businesses, by measuring outdoor water that is considered some of the country’s cheapest. Another would pay farmers for sharing their water downstream, and a third would direct money from mineral-extraction royalties to benefit the lake.

“I long took for granted the lake. It’s always been there, and I’ve assumed it always would be there,” said House speaker Brad Wilson at a summit he convened on the issue. But learning about the lake’s precarious position this summer left him terrified. “The Great Salt Lake is in trouble…We have to do something.”

The shrinking of the lake poses serious risks to millions of migrating birds and a lake-based economy that is worth an estimated $1.3 billion in mineral extraction, brine shrimp and recreation. Health risks exist too: The massive dry lakebed could send arsenic-laced dust into the air that millions breathe.

“The Great Salt Lake needs some leaps to be saved. It’s not going to do it with baby steps,” said Zach Frankel, executive director of the nonprofit Utah Rivers Council. “These are tiny baby steps that should have been taken 20 years ago.”

The lake took a pummeling last year, with especially devastating effects on its microbialites, the Great Salt Lake’s version of a coral reef. The mushroom-like structures are formed by furry, deep green mats of microbes, which are the base of the lake’s food chain and main sustenance for brine shrimp.

The shrimp both support a multimillion-dollar industry supplying food for fish farms and nourish millions of migrating birds whose massive flocks can show up on radar. The lake is also the nation’s biggest source of magnesium and could soon provide lithium, a key mineral for renewable energy batteries.

But last year the lake matched a 170-year record low and kept dropping, hitting a new low of 4,190.2 feet in October. A significant portion of the microbialites were exposed to air, killing the vital microbes. The die-off will likely take years and years to repair even if they are fully submerged again, said Michael Vanden Berg, a state geologist.

And if the water levels continue to drop, the lake could get too salty for the edible microbes to survive, something that has already happened in the bright pink waters of the lake’s north arm.

Still, Mr. Vanden Berg is cautiously optimistic for the south arm, where a portion of the green microbialites did survive last year’s lake drop.

“It’s bad but not catastrophic yet,” he said. “There is still time to fix and mitigate the situation.”

In some ways, the fix is simple: More water needs to flow into the lake.

But that is no small task in the state that grew by 18.4 percent over the past decade, to nearly 3.28 million people.

Utah has relatively inexpensive water overall. A 2015 state audit found Salt Lake City water prices were lower than almost every other city surveyed, including Phoenix, Las Vegas and Santa Fe.

But a subset of homes have access to especially low-price water—the cheapest in the nation, according to the Utah Rivers Council.

About 200,000 homes and businesses pay a flat fee for an entire season of irrigation water. It is called a secondary water system, made from converted agricultural supply in communities that are now largely suburban. Those account for a disproportionately large segment of the state’s water use—and many of them are on the Great Salt Lake watershed, Mr. Frankel said.

“It’s like an all-you-can-eat buffet,” he said. While most people have a water meter on the side of their homes, usage is not measured for secondary-water users.

But small-scale projects have shown that simply being aware of how much they are using makes people cut back by 20 percent, said Utah Representative Tim Hawkes.

There has been pushback to change the system before, and part of the reason is the per-meter cost of about $1,500, but the governor has backed spending about $250 million in federal pandemic relief money to install them.

The Utah Rivers Council would like to see people pay more for that water, but there has been little public discussion of that this year. Hawkes argues that even conserving 20 percent through awareness would dramatically increase the chances that the lake stays healthy.

Yet homes and businesses are not the only ones that need moisture. About 65 percent of the water on the Great Salt Lake watershed goes to agriculture. Farmers have a right to that water, and under historic laws they could lose the water they do not use.

“Right now, there’s actually a disincentive for agriculture to conserve, or optimize, the water they’re using,” said Republican Representative Joel Ferry.

He is sponsoring legislation that would let farmers get paid for water they let flow to the Great Salt Lake and other bodies. Because each farm is so much larger than the average home, even slight adjustments can have a major impact.

Under his plan, which has advanced at the state Legislature, it would be up to each farm to decide whether to sell water in a given year.

“This is going to be a slow start,” said Mr. Ferry, who is a farmer himself. “We recognize there’s a problem, and farmers want to be part of the solution…Ultimately the solutions to this are going to be expensive.”