Greening the desert
Residents in Southern Nevada are being paid to go green – and are ending up with much less green in the process. A unique water conservation plan offers homeowners in Las Vegas and surrounding areas cold cash to rip up their water-hogging lawns, opting instead for landscape designs that conserve water.
Since 2000, when the Southern Nevada Water Authority started the program, it has counted 145 million square feet of turf conversion to date, which equates to a roll of 18-inch-wide sod stretching three-quarters around the world. Homeowners are paid $1.45 per square foot for sod removed from their yards.
The program is the result of a five-year study initiated by SNWA from 1995-2000 that revealed homeowners with lawns used four times more water each year than those with lawns featuring decorative stone walkways and low-water plants and shrubs. The program saves the Southern Nevada region about eight billion gallons of water each year.
“We don’t tell people what to plant in their yards,” says Doug Bennett, conservation manager at SNWA. “We’re not promoting that you go get a yard full of white quartz rock, a wagon wheel and a cow skull. You can plant rose bushes, shrubs, flowers, trees, vines and just about anything.
“We’re just trying to get rid of spray irrigated, high-water use turf grass. We don’t tell people what to plant, just that you have to have a certain amount of plants in your yard to sustain quality of life and quality of appearance. Whatever people put out there, be it drip irrigated trees or shrubs, they all come up with water savings.”
Since 2003, new homes built in Southern Nevada are required to have non-grass front yards. Grass is permitted in back yards in up to 50 percent of the landscaped area. By replacing grass lawns at new construction sites, SNWA saves about 55 gallons of water per square foot per year from those water conversion projects.
“That measure alone has made a dramatic difference in water usage,” says Bennett. “Since that measure was put in place, homes built since 2003 use half as much water as the average home built between 1990 and 2003.”
Broader conservation initiative
The grass replacement plan is part of a much broader water conservation effort put into place a decade ago by the SNWA. It has evolved into one of the nation’s most aggressive water conservation programs. SNVA’s primary conservation focus is the reduction of outdoor water use, which represents about 70 percent of the community consumption. Unlike indoor water, it cannot be recovered.
SNVA’s primary goal is to decrease total water demand to 199 gallons per capita per day (GPCD) by 2035. In 2002, GPCD stood at 314 gallons. Today, demand stands at 245 GPCD.
In 2004, as the Las Vegas area experienced growth of about 30,000 new homes a year, SNVA unveiled its Water Smart Home program, which promotes water efficiency by requiring that new homes include water-smart landscaping and water-efficient furnishings. The EPA has since modeled its national water smart program after the one rolled out by SNVA.
SNVA partnered with the Southern Nevada Homebuilders Association to come up with a series of improvements for new home construction that would make them more water efficient. So far, 7,500 homes have been built to those new standards. Homes built under the Water Smart Home guidelines can save as much as 75,000 gallons of water a year compared to homes built a decade ago.
The latest regulatory change in the Water Smart Home program, unveiled in 2009, requires the use of dual-flush high efficiency toilets (HET) that use as much as 20 percent less water. SNVA has also increased the efficiency standards and requirements for dishwashers and clothes washers.
“As technology advances, you need to make updates to keep the program out in front of the traditional products that contractors might use,” says Bennett.
Bennett added that SNVA is researching additional ways to conserve outdoor watering, specifically the use of smart irrigation controllers, a relatively new technology that utilizes sensor technology to better determine when plants need to be watered. Instead of programming sprinkler systems to water on a fixed every-other-day pattern, for example, when some plants may not need water, smart irrigation controllers monitor outdoor elements like temperature, humidity, wind and soil moisture levels to automatically determine when sprinklers should run.
SNVA’s water conservation efforts have clearly paid off. In a region that averages only four inches of rainfall annually, water use in Southern Nevada declined by approximately 26 billion gallons between 2002 and 2009, despite the addition of 400,000 new residents in that time frame.