CEDAR RAPIDS -- The Iowa Water and Land Legacy coalition announced Tuesday that Cedar Rapids Mayor Ron Corbett and more than a dozen other elected officials and business leaders have joined the effort to secure a sales tax increase to fund the natural resources trust fund.

“We can’t put all the burden on farmers” to clean up the state’s waters. “We need the public financial piece to bring along farmers, landowners and other members of the private sector,” Corbett said.

Iowa voters in 2010 approved by a 63-37 margin a constitutional amendment to create the dedicated trust fund. It has remained empty, awaiting enactment of a 3/8-cent sales tax increase.

Momentum for the sales tax increase has mounted as public awareness of the state’s nutrient-polluted water has grown.

The trust fund spending formula would allocate 71.4 percent of the proceeds, estimated at $180 million a year, to programs that could be applied to best practices outlined in the state’s nutrient-reduction strategy.

“After six years of no action, it’s time to fill the fund and address water quality before judges or Washington, D.C., politicians impose a solution,” Corbett said.

Corbett is one of seven mayors to join the coalition along with Frank Cownie of Des Moines, Jon Kruse of Storm Lake, Bob Scott of Sioux City, Jim Erb of Charles City, John Lundell of Coralville and Ed Malloy of Fairfield.

Kruse, who spoke along with Corbett at a Tuesday news conference, said efforts to improve the quality of the water in Storm Lake have boosted the city’s economy.

“We need the 3/8-cent now. This is the time. We have a great chance to get it over the goal line,” said Mark Doll, chief executive officer of Doll Distributing and co-chairman of the coalition.

At a Sept. 12 news conference, the coalition listed 23 organizations as members. The addition Tuesday of the seven mayors and nine business and community leaders expands the coalition to nearly 40 members.

The new business and community leaders include John Ruan III, CF Industries, Blank Park Zoo, Environmental Law and Policy Center, Pete Brownell of firearms dealer Brownells, Iowa Insurance Hall of Fame member Bill Van Orsdel, Richard Stanley and Joni Axel, both of Muscatine, and Steve Shriver of Brewtopia, the 2014 Corridor Business  Entrepreneur of the Year.