Wednesday, August 10, 2016
Georgia Ballroom (Sheraton Hotel Atlanta)
As of 31 March 2016, over 90 percent of California continued to experience moderate to severe drought for the fifth consecutive year necessitating further conservation of an already limited water supply. The goal of our four year California Department of Water Resources (DWR) research project is to measure water use and reduce water waste at 30 large urban landscapes in six climate zones throughout California that include a variety of ornamental plants with diverse water use requirements that are growing under varying leaf area densities and microclimates. Findings to date indicate: properly functioning irrigation systems with matched heads, proper spacing, proper pressure, and unclogged heads can significantly reduce landscape water waste; distribution uniformity of sprinkler systems can be increased without major redesign and installation efforts by switching to rotary sprinkler heads; landscapes consisting solely of cool season turfgrass use the most water of all planting configurations studied; well mulched landscapes consisting of very low and low water using hydrozones irrigated according to their specific water needs use the least amount of water. The average (mean) overall change in water use across the 30 sites from 2014 to 2015 was -0.286 ETAF. The average (mean) decrease in water use at the twenty five sites which used less water in 2015 was -.451 ETAF while the average (mean) increase in water use at the five sites which used more water was .12 ETAF.