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california Water Today 89 Figure 2.8 Total gross agricultural and urban water use has been decreasing sOURcE: Authors’ calculations using data from California Water Plan Update (california department of Water Resources, various years). NOTEs: The figure shows gross water use. Urban includes residential and nonagricultural business uses. Pre-2000 estimates are adjusted to levels that would have been used in a year of normal rainfall. Estimates for 2000 and 2005 are for actual use; both years had near-normal precipitation. Estimates omit conveyance losses, which account for 6 percent to 9 percent of the total. of drought.) Although California’s population has continued to grow rapidly, water conservation activities and changes in economic structure (notably, less water- consuming manufacturing) have reduced per capita urban water use enough since the mid-1990s to keep total gross urban water use roughly constant (Figure 2.9). Gross agricultural water use appears to have been falling since the early 1980s, due to irrigation efficiency improvements and retirement of some farm- land with urbanization and accumulating soil salinity.10 Despite these declines in farm water use, crop production and the value of farm output continue to rise owing to productivity improvements and shifts to higher-value crops. Over the last four decades, yields have risen at an average rate of 1.42 percent per year as both crop varieties and farming practices have improved (Brunke, Howitt, and Sumner 2005). As farmers have shifted to higher-value horticultural and orchard crops, they have adopted more efficient drip and sprinkler irrigation technologies and management practices.11 Together, rising yields and a shift to 10. Irrigated crop acreage (which counts acreage more than once if it is farmed more than once during the year) fell from a high of nearly 10 million acres in 1980 to roughly 9.2 million acres in the mid-2000s. Irrigated land area (which counts acreage only once) fell from 9.6 to 8.8 million acres (authors’ calculations using data from the California Department of Water Resources). 11. Orang, Matyac, and Snyder (2008) report that surface irrigation decreased by about 30 percent from 1972 to 2001 and drip/microsystem increased by about 31 percent, mostly from reduced field crop and increased orchard and vineyard planting. Most of the switch occurred from the early 1990s onward. Agriculture Total Urban 20001995199019851980197219671960 2005 40 35 30 25 20 15 10 5 45 0Gross water use (maf)