The Metropolitan Water Board will pour an additional $350 million into an increasingly popular rebate program designed to reward property owners who replace grass lawns with drought tolerant plants. But Metropolitan board members approved the funding with new caps on how the money can be paid out to residential and commercial customers, saying that unprecedented demand required modifications to the program.

Metropolitan Water District General Manager Jeffrey Kightlinger said that the changes to the “cash for grass” program were needed to make it sustainable. “It just seemed that there were a very small percentage of applications that were going to be using a very large amount of money. And this whole point of the program is to really get the public to say, ‘maybe ornamental lawns are not the best way to decorate my property.’”

Residential customers in the six-county area served by Metropolitan can replace up to 3,000 square feet of lawn, earning $2 a square foot for a total possible rebate of $6,000. Under a last-minute change, homeowners will be permitted to apply for rebates more than once, as long as the total does not exceed 3,000 square feet replaced.

The biggest changes apply to commercial customers, who formerly had no limits on the amount of turf they could replace and rebates they could seek to reap. Going forward, commercial customers will receive $1 a square foot to replace turf, with a yearly cap of $25,000.

The new rules go a long way to curbing future commercial demands on the program. While 85 percent of businesses that applied sought to replace 25,000 square feet of turf or less, a small number of rebates paid out went “into the millions,” according to Metropolitan staff. And commercial applications have become the largest part of skyrocketing growth: just since the program was suspended for lack of funds, on May 12, $41 million of $47 million in rebate applications came from commercial properties.

Skyrocketing demand brought the popular turf removal rebate program to a halt two weeks ago, when officials exhausted the program's initial allocation of $100 million.

Officials at the regional water wholesaler, which serves an area that’s home to 19 million people, said they saw an “unprecedented increase” in requests for turf removal projects after the state moved to cut urban water use by 25 percent. As part of an executive order last month, Gov. Jerry Brown set a goal that California replace 50 million square feet of lawn with less-thirsty landscaping; Metropolitan says that a square foot of lawn drinks about 42 gallons of water year.

Metropolitan had been offering $2 a square foot for turf replacement to both residential and commercial customers. Homeowners have been the heavier users of the rebate so far, but commercial property rebate requests are on a pace to surpass the residential program soon.

Those numbers had some Metropolitan board members concerned that commercial demand could pick the program clean. “What we’re trying to find here is a sweet spot between capitalizing on historic interest in turf removal and having a sustainable program,” said MWD spokesman Bob Muir.

The program also pays rebates for water-saving appliances and fixtures.

Members of the public and environmental groups including Heal the Bay and TreePeople lobbied Metropolitan’s board for more rules and accountability for the rebate program.

“We’re really getting low impact from the investment,” said Paul Herzog, who coordinates Surfrider’s Ocean Friendly Gardens program. “What’s missing are standards.” Addressing Metropolitan board members, he said, “your class, the California Friendly Landscape training, is teaching standards which are not required in your rebate.”

Liz Crosson, with LA Waterkeeper, said that the program could do more to encourage pollution control, stormwater capture and better landscape design. “This is a broad social and cultural change we need to institute,” she said.

Kightlinger responded that Metropolitan is advising cities in best practices and offering model ordinances for landscaping and irrigation. But, he added, “we cannot mandate how every city is going to administer the program. Are they going to allow bioswales or capturing of water in the front yard? Every city had their own view on this.

“With us it has to be cooperative because we don’t have that legal ability to mandate how everybody should administer the program down.” Kightlinger and the chair of the Metropolitan board, Eastern Municipal Water District’s Randy Record, said they’d be watching the program closely in the future.