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San Luis Reservoir Low Point Improvement Project, California

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U.S. Bureau of Reclamation, Interior.


Notice of intent to prepare an environmental impact report/environmental impact statement (EIR/EIS).


Pursuant to the National Environmental Policy Act (NEPA) of 1969 (as amended), and the California Environmental Quality Act (CEQA), Reclamation and the Santa Clara Valley Water District (District) propose to prepare a joint EIR/EIS for the San Luis Reservoir Low Point Improvement Project (Project). The Project is being proposed by the District to maintain a healthy, clean water supply for the District and other contractors of Reclamation's San Felipe Division. The term “low point” refers to a range of pool elevations in San Luis Reservoir (in Merced County, California) within which seasonal algae blooms can create water quality problems directly affecting the treatability and reliability of deliveries to Central Valley Project (CVP) San Felipe Division contractors (the District is a member of CVP's San Felipe Division). An additional goal of the Project is to increase the operational flexibility of the San Luis Reservoir and to improve the reliability of deliveries to the District and other San Felipe Division contractors. The District will be the lead agency under CEQA.


Reclamation and the District will seek public input on alternatives, concerns, and issues to be addressed in the EIR/EIS through scoping meetings in August, 2002. Scoping is an early and open process designed to determine the issues and alternatives to be addressed in the EIR/EIS. The schedule and locations of the scoping meetings are as follows:

  • Scoping Meeting 1: August 26, 2002, 6:30 to 8:30 p.m., San Jose, California.Start Printed Page 47000
  • Scoping Meeting 2: August 27, 2002, 6:30 to 8:30 p.m., San Luis Reservoir, California.

The draft EIR/EIS is expected to be available for public review at the end of 2003.


Meeting locations are:

  • Scoping Meeting 1: Santa Clara Valley Water District, Board Meeting Room, 5750 Almaden Expressway, San Jose, California.
  • Scoping Meeting 2: San Luis Reservoir Romero Visitor Center, Highway 152, San Luis Reservoir, California.

Written comments on the project scope of alternatives and impacts to be considered should be sent to Mr. Kurt Arends of the Santa Clara Valley Water District, 5750 Almaden Expressway, San Jose, CA 95118.

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Kevin Moody of Reclamation at 1243 N Street, Fresno, CA 93727, telephone: (559) 487-5179. Additional information can also be found at

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The San Luis Reservoir is among the largest reservoirs in the state, and represents a significant component of the District, the CVP, and the State Water Project (SWP) water supply. When water levels in San Luis Reservoir are low, high water temperatures combined with wind-induced mixing can result in algae blooms at the reservoir's water surface, which can extend down more than 30 feet. As reservoir storage drops below about 300,000 acre-feet (approximate elevation 369), algae can be drawn into the San Felipe Division intake structure. This condition can: (1) Cause taste and odor problems; (2) become difficult or impractical to treat; (3) foul drip irrigation systems; and/or (4) eliminate the possibility of delivering any water to the San Felipe Division. To minimize these conditions, the reservoir is currently operated to attempt to maintain reservoir storage above problematic levels.

Recognizing the need to resolve the low point problem, the Low Point Improvement Project was included in the August 28, 2000, CALFED Bay-Delta Program's Programmatic Record of Decision as a complementary conveyance action. The low point problem currently creates water quality, reliability, and operational impacts to the District, other San Felipe Division contractors, the CVP, and the SWP. The results of these impacts are additional operating costs, risks to public health and safety, and economic losses to agriculture and industry. There are also significant opportunity costs to the CVP and SWP as a result of their inability to fully utilize all of the available storage in the reservoir. These impacts will increase in the future as the low point occurs more frequently and for a longer duration. The following summary includes information on San Luis Reservoir, current and future operations, as well as impacts to users.

San Luis Reservoir

Reclamation and the California Department of Water Resources (DWR) jointly own the San Luis Reservoir to store and reregulate CVP and SWP water from the Sacramento-San Joaquin Delta. San Luis Reservoir is an off-stream water storage facility that stores water for both the SWP and CVP; construction was completed in 1967. The State owns a little more than half of the 2,042,000 acre-feet water storage capacity. The reservoir is operated by the DWR; however, operational decisions are coordinated with Reclamation and the CVP. San Luis Reservoir serves as the major storage reservoir and O'Neill Forebay acts as an equalizing basin for the upper stage dual-purpose pumping-generating plant. Pumps located at the base of O'Neill Dam convey water from the Delta-Mendota Canal through an intake channel and discharge it into O'Neill Forebay. The California Aqueduct flows directly into O'Neill Forebay. The pumping-generating units lift the water from O'Neill Forebay and discharge it into the main reservoir. Releases from San Luis Reservoir are made through the Gianelli Pumping-Generating Plant to the San Luis Canal and to the Pacheco Pumping Plant for the San Felipe Division.

Reservoir Water Quality

In the summer months, when water levels are low, water quality deteriorates due to a combination of higher water temperatures, wind-induced nutrient mixing, and algae blooms near the reservoir surface. Algae content is of primary importance during periods of reservoir drawdown, when the surface water elevation drops to within 20 to 30 feet of the inlet to the Pacheco Pumping Plant. Under these conditions, poor water quality may be delivered to the San Felipe Division contractors. Additional factors may also contribute to algae problems in the reservoir. The reservoir is operated as an active offstream storage facility, and therefore, has a relatively short detention time. The reservoir also has an unusual configuration with a very large surface area and a relatively shallow depth (a contributing factor in algal bloom formation and persistence).

Current Operations

San Luis Reservoir is operated by filling in the wet winter months and draining in the dry summer months. Drawdown typically begins in about March and reaches the low point in August or September. Historically, the SWP and CVP have cooperated to try and maintain reservoir elevations above the low point capacity of 300,000 acre-feet.

Future Operations

Although the CVP and SWP have cooperated to try to maintain San Luis Reservoir above 300,000 acre-feet to date, there is no guarantee that they will do so in the future. In fact, as demands on the CVP and SWP continue to grow and Delta export pumping restrictions for environmental purposes occur more frequently, pressure will increase to fully utilize the available storage in San Luis Reservoir.

The State and Federal Governments coordinate implementation of all CALFED projects through the use of a common set of assumptions relative to water supply, hydrology, and operations. The primary method for providing technical consistency is the use of the CALSIM II model for operational studies, which provides a baseline condition for comparing project impacts at current and future levels of development. Preliminary results of CALSIM II operational modeling indicate that San Luis Reservoir will be drawn down below 300,000 acre-feet more frequently and for longer durations in the future.

Impacts to the District

The District has entitlement to 152,500 acre-feet per year of water from the San Felipe Division, which is critical to meeting the demands of 1.6 million residents and important high-technology industries. As storage in the reservoir drops to approximately 300,000 acre-feet, quality, reliability, and operational impacts occur as follows:

  • Water Quality Degradation—Algae entering the intakes could cause: potential impacts on water treatment plant production rates and increased risk of being unable to meet treated water demands; increased risk of exceeding primary water quality standards for disinfection byproducts and secondary standards for taste and odor; and increased costs of both treating water for taste and odor problems as well as for monitoring and responding as impacts occur. Start Printed Page 47001
  • Interruption in Water Supply—If San Luis Reservoir water quality becomes unacceptable for treatment, the supply to the District would be interrupted, which would have a serious water supply, public health and safety, and economic risk to Santa Clara County. Once the reservoir drops to elevation 334 (110 TAF capacity), the Pacheco Pumping Plant is unable to deliver water. This condition would result in an interruption in supply due to water supply availability. However, it is likely that the water supply would be interrupted prior to reaching this condition due to untreatable water quality. In either case, the potential interruption in water supply creates a major reliability impact to the District and other San Felipe Division contractors. The potential interruption to water supply would also occur at the time of year when water supply demands are at their peak.
  • Reoperation of Water Supply System—Due to the risks to water quality and reliability from the low point problem, District operations must be modified annually in order to prepare for a worst case scenario. Modifications typically involve reoperating supply and conveyance systems and/or rescheduling CVP deliveries to minimize reliance on CVP supplies during low point conditions. These actions disrupt District operations and result in additional costs.

Impacts to Other San Felipe Division Contractors

The low point problem also results in water quality and reliability impacts to other San Felipe Division contractors, including the San Benito County Water District, which receives San Luis Reservoir supplies from the Hollister Conduit, and the Pajaro Valley Water Management Agency, which is in the process of implementing a pipeline project to connect to the Santa Clara Conduit for future delivery of San Luis Reservoir water.

Impacts to the CVP

The low point will be an ongoing constraint to the operational flexibility and reliability of San Luis Reservoir and will have increasing CVP impacts. Eliminating the low point operating constraint could improve operational flexibility of the CVP.

Project Objectives

The objectives of the Low Point Improvement Project are to:

  • Resolve the water quality problems associated with the San Luis Reservoir low point. The District and other San Felipe Division contractors want to maintain a consistent healthy, clean, and affordable water supply that meets or exceeds all applicable water quality standards in a cost-effective manner. Reclamation seeks to maintain and protect the water it delivers to CVP contractors. By resolving the water quality problems associated with the San Luis Reservoir low point, the District will be able to better predict the quality of water it is supplied, ensure the health and safety of its water supply, and maximize the efficiency of its water supply and treatment system. Resolving the water quality problems would reduce the risk of exceeding water quality standards, reduce costs of water treatment, reduce operating costs for monitoring, and reduce the risk of exceeding the capacity of drip irrigation filtering systems.
  • Improve the reliability of deliveries to the District and other San Felipe Division contractors. There is a need to improve the reliability of water supplies to the San Felipe Division contractors without adversely affecting deliveries of CVP and SWP water. Improving the reliability of water would avoid public health and economic impacts associated with water quality degradation and potential water supply interruptions. Improving water supply reliability would ensure that existing contract allocations to the San Felipe Division are met by Reclamation and that the District and other San Felipe Division contractors meet their water supply obligations.
  • Increase the operational flexibility of the San Luis Reservoir. There is a need to eliminate the low point operational constraints on the delivery of water from San Luis Reservoir. Through collaborative efforts, Reclamation, the District, and CVP contractors have occasionally modified operations to minimize the potential of San Luis Reservoir dropping below 300,000 acre-feet. However, these operational changes cannot be sustained over the long term as they reduce the likelihood of deliveries of full contract supplies to CVP contractors. A long-term, regional solution is needed to eliminate the constraints on San Luis Reservoir operations. Resolving the low point problem will increase the effective storage capacity in San Luis Reservoir by allowing the State and Federal projects to continue to draw down San Luis Reservoir in accordance with existing operating rules and regulations without impact to the San Felipe Division.
  • Provide opportunities for project-related environmental improvements. In accordance with the District's Ends Policies, an objective of the Project will be to protect environmental resources and to identify project related opportunities for environmental improvements by enhancing or restoring the natural benefits of streams and watersheds. Environmental improvements, where feasible, will be a direct component of the project's integrated solution. The Project, where feasible and appropriate, will also provide project-related opportunities for recreation, hydropower, and flood control benefits. The goal is a multi-purpose project with regional benefits.

Potential Alternatives

A wide range of conceptual alternatives is being considered to address the low point problem. A total of 9 major conceptual alternatives have been identified to date and include:

No Project Alternative

A No Action Alternative that represents existing conditions will be analyzed. The No Action Under Projected Future Conditions will also be analyzed.

Institutional Alternatives

Institutional Alternatives include non-structural measures such as implementation of pumping limitations and amended operation plans or agreements for San Luis Reservoir.

Source Water Quality Control Alternatives

Source Water Quality Control Alternatives would be implemented on-site at San Luis Reservoir. Potential methods under consideration include reservoir aeration, algaecide application, algae harvesting, and managed stratification of waters in San Luis Reservoir.

Water Treatment Alternatives

Potential Water Treatment Alternatives include additional treatment of water supplies by methods such as dissolved air flotation.

Bypass Alternatives

Bypass Alternatives include the construction of pump stations, pipelines, and tunnels that bypass the San Luis Reservoir. Potential routes under consideration include a pipeline originating at the O'Neill Forebay, at the California Aqueduct, or at the Delta-Mendota Canal and proceeding around or under the San Luis Reservoir. The bypass pipelines would terminate at the intake to the San Felipe Division facilities.

Storage Alternatives

Storage Alternatives include expansion of existing District reservoirs, Start Printed Page 47002such as Anderson Reservoir or construction of a new dam and reservoir in the foothills east of the Santa Clara Valley. Potential sites for a new dam and reservoir include Pacheco Reservoir on Pacheco Creek, upstream of the existing Pacheco Reservoir; Packwood Reservoir, east of the existing Anderson Reservoir; Coe Reservoir inside Henry Coe State Park; Los Osos Reservoir south of Henry Coe Park; and Cedar Creek Reservoir southwest of the existing Pacheco Reservoir.

Integrated District Solutions

Integrated District Solutions involve use of existing District facilities such as the groundwater basin, water reuse and recycling, interties with San Francisco Public Utilities Commission, or reconfiguration and reoperation of the District's in-County water transmission and distribution system.


Desalination would involve treatment of alternative supplies from San Francisco Bay or Monterey Bay.

Integrated CALFED Solutions

Integrated CALFED Solutions include use of water supplies from an expanded Los Vaqueros Reservoir or use of an enlarged South Bay Aqueduct to facilitate delivery of SCVWD water supplies.

The draft EIR/EIS will focus on the impacts and benefits of implementing the various alternatives. It will contain an analysis of the physical, biological, social, and economic impacts arising from the alternatives. In addition, it will address the cumulative impacts of implementation of the alternatives in conjunction with other past, present, and reasonably foreseeable actions. The following are issues that have been identified by Reclamation to date: water quality; agricultural and municipal water supply reliability and quality; water supply system flexibility and reliability; diversity of water supply sources; construction-related effects on urban areas and natural habitats.

Interests in Assets Held in Trust

An initial review of available data indicates that there are no known Indian Trust lands that would be affected by the project.

Disclosure of Public Comments

Our practice is to make comments, including names and home addresses of respondents, available for public review. Individual respondents may request that we withhold their home address from public disclosure, which we will honor to the extent allowable by law. There also may be circumstances in which we would withhold a respondent's identity from public disclosure, as allowable by law. If you wish us to withhold your name and/or address, you must state this prominently at the beginning of your comment. We will make all submissions from organizations or businesses, and from individuals identifying themselves as representatives or officials of organizations or businesses, available for public disclosure in their entirety.

Special Assistance

If special assistance is required, contact Mr. Kevin Moody at Reclamation (559) 487-5179. Please notify Mr. Moody as far in advance of the scoping meetings as possible to enable Reclamation to secure the needed services. If a request cannot be honored, the requestor will be notified. A telephone device for the hearing impaired (TDD) is available at (559) 487-5933.

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Dated: June 25, 2002.

Frank Michny,

Regional Environmental Officer.

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[FR Doc. 02-17946 Filed 7-16-02; 8:45 am]