Californians are all right. After mandatory water cuts went into effect earlier in the summer, California residents were able to cut their water use in July by 31 percent, compared to 2013 consumption levels, the Los Angeles Times reports. One way people have saved: ripping up their lawns, and replacing them with drought-resistant plants, like native grasses and groundcover plants. Motivated in part by generous financial rebates offered to those who get rid of their lawns, Californians have removed 150 million square feet of turf, according to the Times. (Recently, the Metropolitan Water District of Southern California ran out of what it thought was six months' worth of refund money in just weeks.)
Do such "cash for grass" programs really help save water? One historical review of lawn rebate programs nationwide offers a clue. According to an undated report by agronomist Sylvan Addink, while the programs do save water, they're also expensive—and don't save as much as you might think. Still, when cities implement a number of other programs at the same time, lawn-replacement rebates can play a helpful part in the conservation effort. Perhaps the rebates work even better now, after mandatory water-use cuts have prompted cities to pass additional laws restricting when and how frequently people can water their lawns.
When cities implement a number of other programs at the same time, lawn-replacement rebates can play a helpful part in the conservation effort.
Addink's report reviews "cash for grass" programs extending back to 1989. It estimates how much of the programs' water savings were attributable to the substitution of grass with drought-resistant plants in people's yards. The results were mixed. In southern Nevada, for example, a program saved, annually, 62 gallons of water per square foot. In El Paso, Texas, by contrast, a program saved only 18 gallons per square foot each year. Much of the savings from the more successful programs seemed to come from requiring participants to install more efficient watering systems, such as drip irrigation lines. Still, Addink attributed one-third of the savings to these more water-efficient plants.
But ultimately, Addink argues in the report, human beings matter more than plants. People can still over-water their yards, whether they contain grass or cacti. City water-saving programs probably work best if they include a mix of strategies, like regulating when people are allowed to water their yards (during cooler parts of the day, and not every day) and making water pricier. Residents have recently taken local governments to court over financially penalizing heavy water use, however, so it's not clear how long that strategy will pass legal muster. That's unfortunate, as research shows hitting people in the wallet is a sure way to make them save water.
Although it's unclear when Addink wrote this "cash for grass" report, it seems likely it was in the early or mid-2000s. So there's one reason to be more optimistic about cash for grass nowadays: Since that time, California cities have implemented numerous water-saving programs, which means yards could already be more water efficient than they were 10 years ago. If this is indeed the case, more marginal programs such as cash for grass might actually make more of a difference, helping homeowners reach the state's ever more stringent water-saving goals in the face of its continuing drought.