A new approach by East Bay Municipal Utility District (EBMUD) to using American River water may also benefit other water agencies in the Bay Area. The strategy of interlocking pipelines and shared storage has the potential to end the battle between EBMUD and Sacramento-area water users, improve the security of EBMUD's water supply, and improve water quality for other Bay Area water suppliers. However, its success is dependent on developing agreements between EBMUD and other entities, many of which have opposed EBMUD in the past on this issue.
Currently, EBMUD draws its water from the Mokelumne River watershed, which meets EBMUD's needs except during periods of drought. It was chosen for its high water quality and proximity to the Bay Area.
However, the Mokelumne is a comparatively small river and its dams provide limited storage capacity. As population grew rapidly in EBMUD's service area, the district contracted with the Bureau of Reclamation for supplemental water drawn from the American River, initially from the Nimbus Reservoir below Folsom Dam. Plans for diverting the water at Nimbus drew an immediate legal challenge, based on the impact on Sacramento water users and the environment. A 1990 court decision (the Hodge decision) allowed EBMUD to draw its water at Nimbus, although the agency must maintain minimum flows through Sacramento at a level higher than required by its contract.
Adapted from EBMUD map; click to enlarge
In the early 1990s, the EBMUD board agreed to delay drawing on the American River, with the attendant capital expenditure, and instead turned to a plan for conjunctive use—joint groundwater storage—of Mokelumne River water with users in San Joaquin County. However, when it became evident that the Mokelumne alone could not supply enough water for the San Joaquin project, the district again began planning to use the American River entitlement to meet customer needs during periods of drought.
Four years of negotiations followed between EBMUD and the Sacramento Water Forum, a coalition of Sacramento-area water interests, resulting in a proposal that would allow EBMUD to draw water from a structure near the confluence of the American and Sacramento Rivers and move it, through new pipelines, into the existing Folsom South Canal and then into EBMUD's existing Mokelumne River aqueducts to the East Bay.
In early 1999 the negotiations broke down. Forum participants insisted that EBMUD commit to abandoning any plans to draw from Nimbus and also guarantee that no American River water would be drawn in dry years. EBMUD was unwilling to abandon the Nimbus plans, even conditionally, until an alternative was completed. Without a conjunctive use plan or some other off-stream storage available to store American River water during wet years, it was also clear that dry years were the time when the additional water would be most needed by EBMUD customers.
During the last decade, some Forum participants asked that the American River issue be included in the CALFED Bay/Delta planning process, but EBMUD was reluctant. The district's environmental process was well ahead of CALFED's, and would allow EBMUD to move ahead immediately once a project was approved. In addition, EBMUD's concern with drinking water quality was not reflected in the CALFED process, which was more focused on the issues of environmental restoration of the Delta and water supply reliability.
However, when CALFED dropped consideration of any Peripheral Canal proposal, alternative ways to meet drinking water needs became a higher CALFED priority. One result was a proposal for an exchange between agricultural users in the Friant Water Users Association, which draws water directly from the San Joaquin River upstream of the Delta, and the Metropolitan Water District, which uses Delta water to serve its urban and suburban customers in southern California. It was clear that such exchanges might also work in other parts of the CALFED planning area. Another possibility was projects that would blend Delta water with high-quality Sierra water to improve drinking water quality to meet CALFED's drinking water quality objectives.
The blending proposals interested EBMUD, which then developed a "modified" proposal for the American River. In this proposal, American River water would be drawn from the confluence structure during wet years, at a maximum rate of 155 cubic feet/second, less than one percent of the Peripheral Canal proposal considered by CALFED. The diverted water could be stored in a facility which would allow blending it with Delta water for the use of East and South Bay water agencies. The most likely storage facility would be the Los Vaqueros Reservoir owned by Contra Costa Water District, which is close to EBMUD's Mokelumne Aqueduct, and has been proposed by CALFED for expansion. Adding a connection to the South Bay Aqueduct would allow the blended water to be used by the Santa Clara Valley Water District as well.
The final CALFED Record of Decision, issued in August 2000, includes a Bay Area blending project as an additional step which could be taken to improve drinking water quality. Regular meetings are now underway between EBMUD, Sacramento water and environmental groups, and the Bureau of Reclamation to find a project which would be satisfactory to the Sacramento stakeholders. Final agreement on the EBMUD/Bureau of Reclamation contract is hoped for by the end of the year.
Additional negotiation will then need to take place on the issue of storing the American River diversion in a Bay Area facility. Under the 1990 Hodge decision, EBMUD's American River water cannot be put to use outside EBMUD's service area. In order for this Bay Area blending project to work, all of the parties to the lawsuit would probably have to petition Judge Hodge to amend his original decision for the benefit of all. In addition, if Los Vaqueros is involved, voters in the Contra Costa Water District must approve expansion of the reservoir.
A critical concern for Sacramento stakeholders will be assurances that any project will be complete and final in itself, and not become the first step in a series of increasing diversions, particularly if additional agencies are part of the blending project. Assurances that are durable and not easily undone or modified will be essential to creating an atmosphere of trust to allow such a project to move forward.
Although CALFED did not become involved in the negotiations over the American River water, inclusion of the blending project in the Record of Decision has established a framework within which any project agreed upon by EBMUD and other parties can then move forward. While the complexity of the planning is a challenge, the potential for solving multiple water supply and quality problems for many Bay Area customers is an incentive for continuing the discussions of this new strategy.
Leslie Stewart
For more information:
EBMUD, 510-835-3000; http://www.ebmud.com