Bulletin 160-93, The California Water Plan Update, October 1994

Chapter 5 Conclusions and Recommendations

Considering that much of the hypothetical range for additional environmental water has now been mandated by the biological opinions and CVPIA, or formally proposed in EPA Bay-Delta water quality standards, California faces more frequent and severe water supply shortages for the year 2000 and beyond. In 1993, an above normal water year, some CVP contractors had their supplies cut by 50 percent. These unanticipated shortages point to the need for a quick resolution of Delta problems through federal cooperation and participation. They also emphasize the need to move forward with demand management and supply augmentation programs at both statewide and local levels. The major conclusions and recommendations in Bulletin 160-93 follow.

Conclusions

• California's population is projected to increase to 49 million people by 2020 (from about 30 million in 1990). Even with extensive water conservation, urban annual net water demand will increase by about 3.8 maf to 10.5 maf by 2020. Nearly half of the increased population is expected to occur in the South Coast Region, increasing that region's annual water demand by 1.5 maf.
• Irrigated agricultural acreage is expected to decline by nearly 400,000 acres, from the 1990 level of 9.2 million acres to a 2020 level of 8.8 million acres, representing a 700,000-acre reduction from the 1980 level. Reductions in projected irrigated acreage are due primarily to urban encroachment onto agricultural land and land retirement in the western San Joaquin Valley, where poor drainage conditions exist. Increases in agricultural water use efficiency, combined with reductions in agricultural acreage and shifts to growing high-value, lower-water-use crops, are expected to reduce agricultural annual net water demand by about 2 maf by 2020.
• The 1990 level and projections of environmental water needs to 2020 include water needs of managed fresh water wetlands (including increases in supplies for refuges resulting from implementation of the CVPIA), instream fishery requirements, Delta outflow, and wild and scenic rivers. Environmental water needs during drought years are considerably lower than average years reflecting principally the variability of natural flows in the North Coast wild and scenic rivers. Average annual net water demand for existing environmental needs is expected to increase by 0.8 maf by 2020. Furthermore, regulatory agencies have proposed a number of changes in instream flow needs for major rivers including the Sacramento and San Joaquin. These proposed flow requirements are not necessarily additive; however, an increase from 1 to 3 maf is presented to envelop potential environmental water needs as a result of proposed additional instream needs and actions under way by regulatory agencies, both of which benefit fisheries.
• With California's increasing population and higher levels of affluence, water based recreation has become an integral part of satisfying urban society's desire to escape from crowded cities. State, federal, and local public water supply projects have helped provide recreation areas in addition to those already provided by natural lakes and streams. In some cases, these projects have enhanced downstream flows during times of year when natural flows are low, thus creating whitewater rafting opportunities that were not possible before reservoir operation. Often there are conflicting values and needs for the same river system. Recreation at reservoirs, natural lakes, and streams must be managed to prevent overuse and degradation.

Recommendations

The Delta is the hub of California's water supply infrastructure; key problems in the Delta must be addressed before several of the Level I options can be carried out. The framework agreement recently signed by the Governor's Water Policy Council and the Federal Ecosystem Directorate will provide an avenue for finding solutions to those problems. The agreement provides for improved coordination and communication among State and federal agencies with resource management responsibilities in the estuary. It covers the water quality standards setting process; coordinates water supply project operations with requirements of water quality standards, endangered species laws, and the CVPIA; and provides for cooperation in planning and developing long-term solutions to the problems affecting the estuary's major public values.

Also, a proactive approach to improving fishery conditions-such as better water temperature control for spawning, better screening of diversions in the river system to reduce incidental take, and better timing of reservoir releases to improve fishery habitat-must be taken so that solutions to the Delta problems mesh with basin-wide actions taken for improving fishery conditions. To that end, many of the restoration actions identified in the CVPIA for cost sharing with the State can improve conditions for aquatic species. Once a Delta solution is in place and measures for recovery of listed species have been initiated, many options requiring improved Delta export capability could become feasible.

Following are the major Level I options recommended to help meet California's water supply needs to 2020. Their potential benefits are also presented. Many of these options still require additional environmental documentation and permitting, and in some instances, alternative analyses. Before several of these programs can be implemented, identification and prioritization of environmental water needs, and funding issues must be addressed.

Demand Management

• Water conservation: By 2020, implementation of urban BMPs could reduce annual urban applied water demand by 1.3 maf , and net water demand by 0.9 maf, after accounting for reuse. Implementation of agricultural EWMPs, which increase agricultural irrigation efficiencies, could reduce agricultural applied water demands by 1.7 maf and net water demand by 0.3 maf, after accounting for reuse. In addition, lining of the All-American Canal and Coachella Canals will reduce net water demand by 68,000 af.
• Land fallowing and water bank programs during droughts: Temporary, compensated reductions of agricultural net water demands and purchases of surplus water supplies could reallocate at least 0.6 maf of drought year supply.
• Drought demand management: Voluntary rationing averaging 10 percent statewide during drought could reduce annual urban applied and net water demand by 1.0 maf in 2020.
• Land retirement: Retirement of 45,000 acres of land with poor subsurface drainage and disposal in the western San Joaquin Valley could reduce annual applied and net water demand by 100,000 af by 2020.

Supply Augmentation

• Water reclamation: Plans for an additional 1.2 maf of water recycling and ground water reclamation by 2020 could provide annual net water supplies of nearly 0.8 maf after accounting for reuse.
• Solutions to Delta water management problems: Improved water service reliability and increased protection for aquatic species in the Delta could provide 0.2 to 0.4 maf annually of net water supplies (under D-1485) and make many other water management options feasible, including water transfers.
• Conjunctive use: More efficient use of major ground water basins through programs such as the Kern Water Bank could provide 0.4 maf of drought year net water supplies (under D-1485).
• Additional storage facilities: Los Banos Grandes (SWP) could provide 0.3 maf of average and drought year net water supplies (under D-1485), and Domenigoni Valley Reservoir (MWDSC) could provide 0.3 maf of drought year net water supplies.

In the short-term, those areas of California relying on the Delta for all or a portion of their supplies face uncertain water supply reliability due to the unpredictable outcome of actions being taken to protect aquatic species and water quality. At the same time, California's water supply infrastructure is severely limited in its capacity to transfer marketed water through the Delta due to those same operating constraints. Until solutions to complex Delta problems are identified and put in place, and demand management and supply augmentation options are implemented, many Californians will experience more frequent and severe water supply shortages. Limitations of surface water deliveries will exacerbate ground water overdraft in the San Joaquin River and Tulare Lake regions because ground water is used to replace much of the shortfall in surface water supplies.

Finally, it is recommended that Level II options be evaluated, expanded to include other alternatives (such as additional long-term carryover storage in both surface reservoirs and in conjunctive operation of ground water basins), and planned for meeting the potential range of average year shortages of 2.1 to 4.1 maf and the potential range of drought year shortages of 2.9 to 4.9 maf. Level II options include demand management and supply augmentation measures such as additional conservation, land retirement, increased water recycling and desalting, and surface water development. Several mixes of State and local Level II options should be investigated and their economic feasibility ascertained to address the range of uncertainty of demand and supply illustrated in the California Water Budget.

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