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demand, in turn, is projected to rise from 6.7 million acre-feet in 1990 to 11.4 million acre-feet by the year 2020 in average water years. Much of the urban growth is projected to occur in hotter inland areas that typically use more water than coastal areas, according to DWR. California's most populous region, the Soufh Coasf, is projected to grow to over 25 million people by the year 2020, requiring an additional 1.5 million acre-feet of water per year for that region alone. And those projected needs loom even larger if water not being used by the other Colorado River basin states is limited and a perma. nent solution to Bay.Delta issues is not found. California has used up to 5.3 million acre-feet of Colorado River water annually, but has now been notified to develop a plan to live within its official annual allocation of 4.4 million acre-feet. Several urban water districts have invested in "off. stream" reservoir projects to maximize supplies. Local off.stream reservoirs scheduled to come on line in the next few years include Contra Costa Water District's 100.000 acre-feef Los Vaqueros Reservoir and Metropolitan Water District of Southern California's (MWD) 800,000 acre-feet Easfside Reservoir. As part of the San Francisco Bay/ Sacramento-San Joaquin Delta solution, or as a means of improving flood management options, it is possible that the tederal or state governments will invest in other off-stream projects, Considered less environmentally intrusive than on-stream dams, off-stream reservoirs generally are constructed to collect runoff waler in above normal precipitation years, rather than by tapping year-round rivers and streams. ',~.", 'l,".,r, I :~; ,.:-i. :~'~ :;"j - i,':'I' J .~ : ~;'!' i .1 Ii! ,,<j.{; ,. .',.- .j 1 "..i_'J. , . . I ". {Ii :1. '. i"~ ,.', 'r':'1 . .';::. :,:':r:~~ Another source of new urban waler under construction is the Coastal Branch pipeline of the SWP. When completed, it will deliver 47.800 acre- feet to water-short Santa Barbara and San Luis Obispo counties. When surface water is in short supply or unavailable, water users, particularly farmers, traditionally have relied on groundwater pumping to supplement their surface water allocations. Some urban areas also rely heavily on groundwater for drinking water. California has an estimated 250 million acre-feet of accessible groundwater in 450 basins and uses between 7.5 million acre-feet and 12.2 million acre.feet of groundwater per year. This water source has been largely unmetered and unregulated by the state. but more and more local agencies are adopting plans to manage groundwater basins and reduce overpumping. WHY IS WATER CONSERVATION IMPORTANT? As California's water balance has tipped toward the negative, competition has increased among the three main water stakeholders - agriculture, urban and the environment - and conservation may be one tool to manage that competition. Conservation also can help reduce the need to use groundwater. may defer the need for some new supply or storage facilities, and can help make surface water available to protect fish and wildlife habifat. Conservation also is a key factor in ongoing debates about the future of the Bay-Delta, the heart of California's water system. Competing factions representing agriculture, urban users, environmental interests, and government agencies reached agree- ment in 1994 to participate in a collaborative process to try and develop solutions to the chronic and divisive Bay-Delta issues such as water allocation, habitat preservation, and declining water quality. Participants are scheduled to complete their work by the end of 1998, and water use efficiency is one of several core issues being considered in the process. To illustrate the competition for water flowing Ihrough the Delta. consider the 1993 water year. Despite above-normal runoff that year, five previous years at drought and the need to provide water for environmental purposes limited CVP deliveries to 50 percent of contracted supply for federal water service contractors from Tracy to Kettleman City. Because of uncertainty about the outcome of proposals to protect aquatic and wildlife species in the Delta. water-supply reliability will continue to be uncertain for those who depend on Delta exports. the 1993 update of the California Water Plan warned. The last drought cycle left a permanent legacy of institutionalized water conservation practices across much at the slate. Ultra low-flow plumbing fixtures are now mandated for new buildings, as well as for retrofits. Farmers and landscapers now use com- puters to optimize irrigation, and manufacturers have reduced water used by automatic dishwashers and olher appliances. Incentives to encourage water reuse and recycling are in place or are being developed to maximize existing water supplies. C(l/~rorni(l \- populatioJl is projected to re(lch ./9 million hy thl' year 2020. AI/nual urhan Imler demand. in tllm. is projec[l'd 10 rise from 6,7 millionllcre-feer 10 11.4 million acrl'-feel. 5