Report Redding Basin Water Resources Management Plan Environmental Impact Report Prepared for Shasta County Water Agency January 2007 2525 Airpark Drive Redding, CA 96001 Executive Summary The Redding Basin (Basin) is bisected by the Sacramento River, the largest river in California, and is bounded on the north by the largest reservoir in California, Shasta Lake. The Basin also typically receives the most precipitation in California’s Central Valley. Despite these water supply attributes, the water supplies available to a majority of the Basin’s water purveyors are not adequate to meet current water demands in dry years. Historically, the Redding Basin has been characterized by low population density and abundant natural resources. However, population growth in the Basin and potential cutbacks in surface-water supplies during drought conditions increase the possibility and magnitude of water supply shortfalls in the near term. Additionally, increased competition for surface-water supplies in other parts of the state for urban, agricultural, and environmental uses has stretched the current water delivery system beyond its original intended purposes. Operation of the current statewide system under drought conditions further impedes future water availability for many water purveyors. Recognition of these challenges led to the initiation of the Redding Basin Water Resources Management Plan (Plan), which has resulted in several important findings: • Collectively, basin purveyors will be water short in a critical dry year. • Comprehensive and affordable solutions exist that would improve water supply reliability. • Water transfers involving additional water from conjunctive use and/or water use efficiency projects are key to meeting Basin needs. • A new institutional framework is necessary to implement the Plan and preserve autonomy of the purveyors. • Monitoring is necessary to adapt the Plan and respond to future uncertainties. Flexible, affordable solutions exist that both preserve the autonomy of water purveyors and ensure adequate water supply reliability through the planning horizon, which is the year 2030. This Environmental Impact Report (EIR) evaluates the physical and social effects of implementing various water resources management actions identified in earlier phases of this regional planning effort. The Shasta County Water Agency is lead agency for preparation of the document under the California Environmental Policy Act (CEQA). This document was also developed to comply with the National Environmental Policy Act (NEPA). The U.S. Bureau of Reclamation (Reclamation) agreed in February 2005 to act as a lead agency under NEPA during the development of the EIR. After the release of the administrative draft document, Reclamation determined that the proposed actions were not defined well enough to justify its participation in that role. This delayed the release of the draft document while additional analysis was performed. However, additional analysis did not resolve Reclamation’s concerns. After extensive consideration, the Shasta County Water RDD/053030004 (CAH3246.DOC) II EXECUTIVE SUMMARY Agency made the decision to publish a CEQA-only document without a NEPA lead. Future actions that result from the Plan will be subject to NEPA review, and this document has been developed to facilitate that. Study Area The study area for this report is bounded on the north by Shasta Lake, on the south by the southerly boundary of Anderson-Cottonwood Irrigation District (ACID), on the west by Whiskeytown Lake, and on the east by the Palo Cedro area. The study area includes the Cities of Redding, Anderson, and Shasta Lake, the Town of Cottonwood, and surrounding unincorporated areas. The Basin has a population of about 150,000 people, encompasses approximately 275,000 acres, and includes the service areas of the water purveyors shown on Figure ES-1. Basin water purveyors supply water for a variety of municipal and industrial (M&I), agricultural, and recreational water uses. Various physical, legal, economic, and institutional factors affect the availability and reliability of surface- water and groundwater supplies. These factors affect different purveyors in different ways and to different degrees. Some purveyors have access to multiple supply sources through different surface- water diversions or multiple surface-water or ground- water pumping facilities. Purpose and Need Statement The purpose of the action is FIGURE ES -1 to implement a regional REDDING BASIN WATER PURVEYORS water resources scheme to improve water supply reliability throughout the Basin. This proactive regional approach would preserve local decision-making authority and local water rights, thus insulating local resources from the full impact of statewide droughts. Additionally, the Plan would promote better water management in the Basin, particularly during drought years, through groundwater management, system improvements, and better integration of surface-water and groundwater supplies. RDD/053030004 (CAH3246.DOC) III EXECUTIVE SUMMARY This action is needed because of increasing demands on existing water supplies, especially during drought years when purveyors that rely exclusively on Central Valley Project (CVP) water supply contracts are particularly vulnerable to supply shortfalls. Alternatives Considered Previous phases identified conceptual alternatives to increase water supply reliability, specifically: • Emphasis on surface-water transfers • Emphasis on groundwater development • A mix of surface-water transfers and groundwater development These alternatives rely on water transfers to address geographic imbalances of water supply and demand. These alternatives have been refined for consideration in this document. Based on detailed review of water demands, water budgets, and recent renewals of federal water supply contracts, the conceptual alternatives outlined above have been revised and parsed into current and projected levels of development. Current Level of Development (2005 Condition) Alternatives to address current conditions are compared against a baseline condition called the No Project Alternative. The No Project Alternative is simply the current condition in the absence of the Plan. All of the proposed “Action” Alternatives include measures that could be implemented immediately to increase water supply reliability. These measures include the following: • Common Resources Pool (common pool) for shared use of water resources in the Basin. The common pool would provide a mechanism for water to be transferred within the Basin on a long-term or short-term (year to year) basis. The advantages of a common pool are that transfers could be accomplished under pre-approved “umbrella” contract terms with the resource management agencies as opposed to negotiating individual agreements and seeking regulatory approval for transfers on a case-by-case basis. • Target Reliability Factors (TRF) would be implemented in critical dry years. TRF indicate voluntary demand reductions that purveyors would enact in critical dry years. Demand would be reduced to 90 percent of the average annual M&I demand and 75 percent of the average annual agricultural demands for each purveyor under critical dry year conditions (a 1-in-10-year supply cutback). Future Level of Development (2030 Condition) Alternatives to address future conditions are compared against a baseline condition called the No Action Alternative. The No Action Alternative is the likely condition that would develop by the year 2030 in the absence of the Plan. The proposed “Action” Alternatives include physical projects that would be developed as needed, but before 2030, that would improve water supply reliability. These Alternatives include the following: • Alternative 1 – Conjunctive Use would develop a series of groundwater wells within the ACID service area. The wells would allow ACID to provide groundwater to its RDD/053030004 (CAH3246.DOC) IV EXECUTIVE SUMMARY customers, thus freeing up surface water for transfer to other purveyors in the Basin. The wells would be installed incrementally, as needed to meet growing demands. It is estimated that approximately 20 new agricultural wells capable of pumping 2,000 to 4,000 acre-feet each would be installed at full build out, with a maximum annual withdrawal of 44,000 acre-feet. The wells would be distributed throughout the ACID service district, just south of the City of Anderson. • Alternative 2 – Water Use Efficiency would provide water savings from improvements to ACID’s aging system of canals and laterals. Inefficient system facilities result in inordinately high system losses; about 50 percent of water entering the system is lost to seepage, operational spills, or other losses before delivery to customers. System improvements would consist of three canal lining projects along the main canal that would reduce seepage in sections of the canal identified to contribute greatly to water losses. Lining of these sections would result in an estimated water savings of 4,000 acre- feet which could be redirected throughout the Basin. • Alternative 3 – Combination would combine the Conjunctive Use and Water Use Efficiency alternatives, as described above, to meet critical dry year demand projections for the year 2030. Preferred Alternative For this document, the preferred alternative is Alternative 3, which maximizes the operational flexibility of the Basin’s water resources and best improves water supply reliability in the Basin. Impact Summary A number of potentially significant