October 21, 2004 :: No. 66

Engineer Designs Sprinkler Nozzle That Avoids Water Runoff and Waste

California, despite its lush parks, grasslands and front yards, is a desert, which makes water nearly as precious to the state as gasoline.

That’s why a Cal State Fullerton assistant professor of civil and environmental engineering has designed a specialized sprinkler that will keep the desert looking green without wasting a limited natural resource.

With the support of a $33,000 U.S. Department of the Interior grant, Prasada Rao has designed a sprinkler nozzle that can be adjusted to spray water in as small an arc as 4 feet or as large as 12 feet — and any length in between. Further, his design allows a single sprinkler to water in up to six directions and six different lengths to cover that pear-shaped lawn, oval planter or grass along a winding walkway.

His creation has generated interest from both industry and government officials. A patent on the sprinkler head is pending.

This Friday, Oct. 22, Rao will serve as a panelist on “Technology and Inventions” at the Southern California World Water Forum sponsored by the Metropolitan Water District. Last month, Rao and Meena Westford of the U.S. Bureau of Reclamation teamed for a joint presentation about the new nozzle to the California Urban Water Conservation Council in Santa Barbara.

“Existing sprinkler nozzles perform well for landscape areas that are laid out in square or rectangular patterns,” said Rao. “Where there are curved driveways, the sprinkler will spray water on non-lawn areas and contribute to water waste.”

The engineer noted that according to a U.S. Geological Survey, of the 26 billion gallons of water consumed daily in the United States, approximately 30 percent, or 7.8 billion gallons, are used outdoors— a significant portion of that on landscaping. And in arid regions, like California and other states in the southwestern United States, the amount of water consumed daily for watering plants, lawns and gardens can be as high as 60 to 90 percent.

Therefore, Rao noted, it is vital to ensure that water is being used for its intended purpose and not flowing down city streets to drains that carry the water — as well as trash and other pollutants picked up along the way — to the ocean.

“In Orange County last year, we saw portions of our beaches closed to public use or advisories issued for an accumulated total of 1,329 days for all county beaches because of polluted water. In Los Angeles County, it was 1,459 days,” Rao added.

“With a growing population and dwindling water sources, the advantages of using the proposed sprinkler nozzle are manifold. An improved sprinkler system can open new windows for improved landscape design. Since urban lifestyle and good landscaping go hand in hand, an offshoot of this work is an enhanced quality of life. With rising water costs and depleting water sources, the proposed sprinkler can benefit both the user and water management agencies.”

Rao noted that the Department of the Interior and other water agencies are focusing on developing new technological tools to aid in conservation. “We are hoping this sprinkler nozzle will revolutionize landscaping in the years to come,” he added. “There is nothing on the market now that will do this job.”

The device is similar to the pop-up sprinkler nozzles currently found in hardware and home-improvement stores across the country, noted Rao. The nozzle can replace current sprinkler nozzles used by residential users, and also be deployed by city, county and state agencies for parks and other municipal uses.

Earlier this year, a federal omnibus appropriations bill earmarked $100,000 to further Rao’s research in developing sensors to identify substances placed in the water supply that could harm drinking water. Rao, who earned his doctorate at the Indian Institute of Technology, has been a member of the Cal State Fullerton faculty since 2002.