Water Supply for Future Needs Meeting our future water needs will require implementation of a combination of strategies. Two basic strategic approaches are demand management and supply development. Through demand management, water purveyors make wiser use of the available water thereby lessening the need for new source development. Supply development strategies include a variety of methods for increasing supplies and improving supply reliability. Increasing demands and competition for our limited resources oblige water managers and suppliers to implement both demand management and supply development strategies. However, each option needs to be evaluated on a case-by-case basis for suitability, cost effectiveness, and public acceptance. The time is past when water supply needs can be met simply by developing more water withdrawal, storage, and delivery systems. Demand management must also be part of any long-range water supply plan. By reducing demand, new supply developments can be delayed with potential savings to the users. Demand can be managed through conservation measures and alternate strategies such as effluent reuse, grey water use and dual water systems. Figure 2-10 compares the average amount of water used per person per day in cities in Nevada and other western states. Though urban water utilities and local governments encourage conservation through tiered pricing, limited landscape watering days, and low-volume appliances, the data suggest that there is room to improve upon conservation and other demand management strategies.   (Note:  A direct comparison of average water use between cities must consider different climate and water supply circumstances. For example, other cities receive summer rains or use other water sources for lawn watering, thereby reducing public supply system water use.) Even as more effective demand-side strategies evolve, water supply development strategies also need to include methods for increasing supplies and improving reliability. The supply-side strategies described below may not be appropriate in all situations and must be examined on a case-by-case basis. Use of existing committed and uncommitted supplies refers to water suppliers that further utilize supplies under their existing water rights and/or obtain new appropriations for unallocated water. Water transfers involving a water rights purchase or lease from one user for use by another. Groundwater recharge and recovery or artificial aquifer recharge, is a water resource management option available to some areas as a means of securing more reliable water supplies during periods of low surface water flows. This strategy involves ponding or injecting surface water when abundant, to enhance aquifer recharge for later use. State water law provides criteria for establishing groundwater recharge/recovery programs. Currently, the State Engineer's office has sixteen (16) recharge applications and permits on file, with a total potential recharge of 93,709 acre-feet per year. Conjunctive use, in which different supply sources (e.g., surface and groundwater) are used in combination or in alternating periods, depending upon the relative abundance of each. When surface water supplies are abundant, excess is stored in aquifers, and groundwater use curtailed, optimizing natural recharge. Conversely, when surface supplies are low, stored surface water and recharged groundwater can be used to make up for limited surface water supplies. Desalination requires the use of a processing plant to remove dissolved minerals (including but not limited to salt) from seawater, saline water, or treated wastewater. Cloud seeding is a weather modification technique involving the injection of silver iodide or other compound into clouds to increase precipitation. The estimated additional amount of water obtained each year has varied from 35,000 to 60,000 acre-feet during the 1990's. Reclamation or restoration of deteriorated watershed conditions to reduce surface runoff and enhance groundwater recharge conditions, and by land use planning considerate of the relationship between water resources and development patterns. Efforts to raise Pyramid Lake water level exemplify the types of water management strategies that are essential in our desert region. Since 1981, the lake level has risen about 30 feet, recovering a portion of the 80-foot decline that occurred in the first half of the 1900's. Though most of the recent increase came during wet winters in the Truckee River watershed, modified supply strategies and use practices have helped to get more water to reach the lake and stop further lake declines during drought years. Measures include: conjunctive use of the Carson and Truckee River to meet agricultural water supply requirements in Lahontan Valley; identification and curtailment of non-essential uses; conservation measures implemented by farmers in the Truckee Carson Irrigation District and residents and businesses in Reno and Sparks; and, the transfer of water rights to maintain higher river water quality during droughts. In southern Nevada, innovative management strategies are being used to secure water from the Colorado River for the growing population and economy in Clark County. Water suppliers and government agencies have worked out agreements that permit Nevada to store a portion of the state's share of Colorado River water in Arizona aquifers. Southern Nevada water suppliers will be able to draw a proportionate amount of water from the river and Arizona will have access to the groundwater for future use. Growing water demand and diversification of water uses is occurring in numerous other water basins (e.g., Carson Valley and Walker Lake). Each presents unique opportunities to develop creative supply and demand strategies that add value to the water resources for all Nevadans Water for Instream Use Balancing "off stream" uses of water with "instream" uses always will present challenges in this arid region. When the state legislature officially adopted the prior appropriation doctrine, a diversion was a key to claiming a water right. In any event, the Nevada Supreme Court has determined that state water law gives the State Engineer discretion to grant a water right for instream flow or to maintain a minimum pool in lakes and reservoirs. Though a portion of the water diverted gets returned, water conditions gradually become less hospitable to native plants and animal species further downstream due to annual and seasonal depletion of surface waters and deterioration of water quality. Many native fish species no longer inhabit state waters, and more are classified threatened or endangered. Relatively few water rights, however, have been acquired for instream uses. Ironically, urban population growth and economic growth appears to correspond with heightened public interest in improving instream water supplies. Improvements in water quality, water-based recreation, aquatic habitats, and scenic quality are some of the benefits various interests seek to gain or protect on behalf of the public. In recent years, agencies, conservation organizations, and some local governments have shown interest in acquiring water rights from willing sellers to retain more water in streams, reservoirs, and wetlands for environmental, biological, and recreational purposes. Often, the opportunity to acquire water rights and transfer the beneficial use for instream uses arises as property owners convert private agricultural land to another land use, such as urban, commercial, or industrial development. The sustainability of farming and ranching in downstream rural communities is an important consideration. Most of the water planning and acquisition activity has occurred in the Truckee and Carson River basins to improve water quality, stream flow conditions, fisheries at Pyramid Lake, and wetlands in Lahontan Valley. Water rights have been acquired for some state Wildlife Management Areas and other locations (e.g., Meadow Valley Wash, Upper Blue Lake, and the Bruneau River) (Division of Water Planning, 1999b). State agencies involved with instream water rights include the Divisions of State Lands, Wildlife, and Water Resources. Next Page -- Surface and Groundwater Quality Back to Table of Contents