Seawater Intrusion into Groundwater Aquifers

in the Salinas and Pajaro Valleys

Monterey and Santa Cruz Counties

Commencing on May 31, 2000 -- 9:00 a.m.


Salinas City Hall Rotunda/200 Lincoln Avenue/Salinas, California




The State Water Resources Control Board (SWRCB) will hold a public workshop to receive progress reports from the Monterey County Water Resources Agency (MCWRA) and the Pajaro Valley Water Management Agency (PVWMA) regarding their efforts to control seawater intrusion into the groundwater aquifers in the Salinas Valley and the Pajaro Valley. The SWRCB will also receive comments and recommendations from the public on the seawater intrusion issue.




The groundwater in the Salinas Valley has been degraded by seawater intrusion and nitrate pollution. The SWRCB considered commencing an adjudication under its authority contained in Water Code sections 100, 275, and 2100, et seq, and Article X, Section 2 of the California Constitution to address these problems. However, the SWRCB elected to encourage a local solution to these water quality problems. Therefore, the SWRCB postponed any adjudicatory action to allow the MCWRA an opportunity to develop and implement a local solution.


MCWRA plans to pursue a phased approach to addressing the seawater intrusion and nitrate pollution problems in the Salinas Valley. The first phase of the project includes modifications to the Nacimiento Reservoir spillway, which would allow an increase in the amount of water MCWRA is able to store in the reservoir. This phase also includes construction of an in-stream diversion structure and expanded distribution system to enable MCWRA to make surface water deliveries to offset pumping in the area of seawater intrusion. Components of the plan that would provide the greatest benefit at the lowest cost would be implemented first.


In a letter dated May 27, 1998, the SWRCB requested MCWRA to provide an oral progress report at the SWRCB's January 1999 Public Workshop. In that letter, MCWRA was reminded that an appropriate plan for addressing seawater intrusion and nitrate pollution needs to include specific goals, a time frame for achieving those goals, and an appropriate mechanism for monitoring and evaluating the effectiveness of the plan. The SWRCB also requested that MCWRA identify a funding mechanism and a contingency plan in the event that the anticipated funding mechanism failed.


MCWRA provided a progress report to the SWRCB at its January 6, 1999, Workshop. During the workshop, MCRWA presented information on its draft Environmental Impact Report (EIR) and Project Plan for the Salinas Valley Water Project. The SWRCB requested that MCWRA provide periodic progress reports on its efforts to control seawater intrusion.




Seawater intrusion into aquifers in the Pajaro Valley was recognized as a serious problem as early as 1953. Studies by state and local government agencies concluded that there was a need for increased groundwater management efforts or development of supplemental water supplies to address the problem.


In 1993 PVWMA developed a basin management plan and EIR identifying various alternatives to address the seawater intrusion and groundwater overdraft problems. The preferred alternative incorporated a number of components including construction of a pipeline and importation of approximately 20,000 acre feet of Central Valley Project water, enhanced recharge to the groundwater system, implementation of a conjunctive use program, construction of a distribution system, and implementation of water conservation measures. Currently, PVWMA plans to implement various components of the preferred alternative in phases.

Local projects and water conservation measures are unlikely to generate enough yield to fully address the seawater intrusion problem. Identifying additional sources of water was an important component of the preferred alternative. However, in 1998, the voters in the Pajaro Valley approved a measure to place the proposed pipeline construction project, which was an integral part of the seawater intrusion control program, on hold for at least ten years.


In October 1997, the SWRCB reserved

$5 million from Proposition 204 funds for the PVWMAs seawater intrusion control projects. The SWRCB informed PVWMA that, in light of the funding made available by the State, the agency would need to show that it was making progress on solving the seawater intrusion and overdraft problems in a timely fashion. The SWRCB has also asked PVWMA to provide semi-annual progress reports on its efforts to control seawater intrusion. The PVWMAs May progress report will be presented during this workshop.


On November 16, 1999, PVWMA submitted an application for the $5 million Proposition 204 reservation to conduct the Watsonville/Harkins Slough project. The project purpose is to reduce pumping from the Pajaro Valley Groundwater Basin, thereby reducing seawater intrusion. The project consists of facilities to divert wet weather flows in Harkins Slough to a recharge basin for storage in groundwater, to extract the stored flows as well as additional supplemental groundwater during the irrigation season, and to deliver the water to farmers to replace their individual well supplies. The total estimated eligible project cost is $12.35 million for construction and construction administration.


At its June 15, 2000 meeting, the SWRCB will consider a resolution approving funding from the Seawater Intrusion Control Loan Program in the amount of $5.0 million for the Watsonville/Harkins Slough Project.




The purpose of the workshop is to receive comments and suggestions to assist the SWRCB in addressing the impacts of seawater intrusion. The issues include (1) is MCWRA taking adequate measures to control seawater intrusion into aquifers in the Salinas Valley, and (2) is PVWMA taking adequate measures to control seawater intrusion into aquifers in the Pajaro Valley.




This is an informal workshop. There will be no sworn testimony or cross-examination of participants, but the SWRCB and its staff may ask clarifying questions.


Participants are encouraged to provide written comments by 5:00 p.m. on Wednesday,

May 24, 2000. The SWRCB requests that

15 copies of written comments be sent to

Tom Peltier at the mailing address indicated on the top of the first page of this notice. Additional copies for participants in the workshop should be provided to the SWRCB on the day of the workshop.


Participants are encouraged to summarize their written comments in their oral presentations. MCWRA and PVWMA will be allowed thirty minutes to present their progress reports. To ensure that all participants have an opportunity to participate in the workshop, oral presentations may be limited to five minutes or less. Participants with similar comments are requested to make joint presentations.



The enclosed map (not electronically available) shows the location of the Salinas City Hall in Salinas. Parking at the City Hall is by permit only. Other parking is available at a garage located a few blocks away on Lincoln and West Alisal. The rotunda is accessible to persons with disabilities.


Questions concerning this notice may be directed to Tom Peltier of the Division of Water Rights at (916) 657-1526 or (FAX

675-1485) or Barbara Katz, Staff Counsel, at (916) 657-2097.



Maureen March

Administrative Assistant to the Board


Dated: May 4, 2000