Dozens of projects to protect Minnesota waters from invasive species, toxic algae and other threats — as well as plans to expand and rebuild parks and trails across the state — may come to a halt over a partisan legislative battle.

A fight between the DFL-controlled House and GOP-led Senate has blocked the spending of a $61 million environmental trust fund for the first time since voters created the fund in 1988 with tax dollars collected from the state lottery.

The impasse, which centers on the state's adoption of stricter car emission standards, threatens about 80 projects. It could cut off a key source of funding for some of the most pressing environmental matters: slowing the spread of invasive zebra mussels and carp, stabilizing moose populations, bringing back pollinators and other once-common species that have been dying off, and finding out why toxic algae blooms on lakes and ponds have recently been appearing in even the most remote and protected corners of the state.

The impasse also may block funding to help cities replace trees killed by the emerald ash borer and delay plans to expand hiking trails and campgrounds and set aside conservation and hunting lands throughout the state.

There is still hope that lawmakers will reach a deal and free up the funding when they are called back in a special session as early as next week to discuss Gov. Tim Walz's emergency powers during the pandemic. It's unclear exactly how far apart the two sides are since the issue has been swept up into a broader partisan battle.

The House and Senate each passed their own funding proposals for the $61 million earlier this year. Their project lists were almost identical, with disagreement over just $1.5 million of the total.

Senate Republicans tried to set aside the $1.5 million to help small towns and cities pay for wastewater treatment improvements. But House DFLers and environmentalists objected, arguing that the state traditionally bonds for those types of projects and that opening up the environmental fund for sewage and treatment plants would make it vulnerable to future raids.

Republicans dropped their proposal and instead demanded that Walz and the Minnesota Pollution Control Agency (MPCA) suspend for another two years their plans to adopt California's stricter emission standards for cars and trucks. The vehicle emission standards, which were announced last year, are set by the MPCA and do not require lawmaker approval.

Those standards have nothing to do with the environmental trust fund or its projects, said state Rep. Rick Hansen, DFL-South St. Paul, who wrote the House's funding proposal.

In a public meeting last week, Hansen told the Legislative-Citizen Commission on Minnesota Resources — a group of citizens and lawmakers that recommends which projects should get trust fund dollars — that under the normal rule-making process it will already take the MPCA longer than two years to adopt the new standards.

"There is automatically a two-year delay for implementation," Hansen said. "The earliest it could happen is five years away."

State Sen. Bill Ingebrigtsen, R-Alexandria, said that while the governor has a right to adopt stricter vehicle standards without approval from lawmakers, the issue is big enough that it shouldn't be decided by one person.

"We're just asking for two years off, to let a new Legislature come in and take a look at it," he said. "I don't think that's unreasonable."

Ingebrigtsen, who wrote the Senate's funding proposal, said that the trust's proposals were lumped together into a single law with broader funding for the MPCA and other agencies, making it fair game to negotiate the powers of the MPCA along with the fund.

Negotiations have been hampered this year as the coronavirus has made it harder for the two sides to meet, he said. Even if a deal can't be reached, the money is not going away anytime soon, Ingebrigtsen said.

By law, the Legislature has until June 2021 to spend the trust fund money. Lawmakers said they didn't know what would happen if a deal isn't reached by then. A year's delay, Hansen told the commission, would upset ongoing research that relies on studies and data that must be collected before next June.

"There are about 250 jobs in there," Hansen said.

The delay has already caused a backlog of proposals, said Becca Nash, director of the legislative-citizen commission.

Many of the researchers who would have received funding this year have reapplied for funding from next year's pool of grants, essentially putting two years of funding up in the air, Nash said.

In a vote early this month, the commission decided not to revisit or recommend any of the projects that were supposed to receive funding this year for a second time, in the hope that a deal will be reached.

"We're just going to let the Legislature keep going right now," Nash said.