For decades, developers of housing, shopping malls and hotels have been able to build on Florida's wetlands by either helping to restore or clean up wetlands at a different location.

But those wetland mitigation banks, used to offset the adverse impact of development, are drying up across the state, especially in south Florida.

The Everglades Mitigation Bank and the Hole-in-the-Donut banks have had 9-12 month periods without any credit, and the Loxahatchee bank will run out in five to six months, experts said.

Legislation introduced in both houses this session seeks to remedy that pending crisis by opening the gates for local governments to allow developers to restore local public lands bought for conservation if no state or federal mitigation bank credits are available.

“We are running out of wetland credits,” Jose Gonzalez, representing the Builders Association of South Florida, told members of the House Agricultural and Natural Resources Subcommittee Tuesday afternoon.

The House version, sponsored by Rep. Lawrence McClure, R-Plant City, and Rep. Toby Overdorf, R-Palm City, had its first hearing today, where it was approved with one dissenting vote from Rep. Delores Hogan Johnson, D-Fort Pierce.

Mitigation banking “has not been faring well over the historic view,” Hogan Johnson said. She described a housing development in her district built on wetlands that causes people to almost be flooded out of their homes whenever there is a big rainstorm.

“I have concerns with messing with nature, I am putting it out there like that,” Hogan Johnson said.

McClure said that moving mitigation from the private to the public sector “is the exact reason for this bill.”

The bill is not changing the mitigation banking process, just allowing an alternative when there are not enough credits available, he said.

A similar bill in the Senate sponsored by Sen. Tom Lee, R-Brandon, and Sen. Gary Farmer, D-Fort Lauderdale, has had bipartisan support. It made it out of the Senate Community Affairs Committee unanimously last week.

Passage of the legislation would reverse a seven-year prohibition of local governments providing mitigation functions that was stuck as a rider onto a transportation bill by private mitigation bankers in 2012.

“Our concern is that this expands the scope of of the use of mitigation when wetlands are destroyed,” said Aliki Moncrief, executive director of Florida Conservation Voters.

Her organization didn’t have time to analyze the bill or take a position on the measure but had lots of unanswered questions.

“We are portraying wetland mitigation as a positive thing but what is actually happening is developers are destroying them in one place and putting them someplace else,” Moncrief said.

She also said the crisis at hand raises the larger issue of whether wetland mitigation is actually working, adding there has not been a Department of Environmental Protection study on mitigation since 2007.

Wetlands mitigation is an ongoing concern for environmentalists, said Brad Cornell of Audubon Florida, especially when studies have shown it hasn’t been effective.

“We have reports from Audubon science staff and the U.S. Fish and Wildlife staff and NOAA, that we’ve continued to lose wetlands,” said Cornell, who is based in Naples. “We are not doing a good job compensating for wetland destruction.”

The problem is state policy that allows developers to use uplands and the clearing of invasive species to count as mitigation, he said, strategies that don’t really preserve the function of wetlands to filter and store water.

“If you lose actual acreage of wetlands through a permit and allow uplands or exotic clearings to replace those wetlands, you have lost ability to store and clean water on the land,” he said. “Not having a good tight control on wetland mitigation strategies that work means that we are going to lose more wetland.”

Contact Schweers at jschweers@gannett.com. Follow him on Twitter @jeffschweers.