Meeting Date:

June 15, 2009





Darby Fuerst,




General Manager

Line Item No.:


Prepared By:

Andrew M. Bell

Cost Estimate:



General Counsel Approval:  N/A

Committee Recommendation:  N/A

CEQA Compliance:  N/A


SUMMARY:  In 2008, the Board directed staff to investigate the feasibility of increasing the storage capacity of Los Padres Reservoir.  The purpose of the project would be to create additional storage capacity in the reservoir so that stored water could be released to increase streamflow in the Carmel River to benefit the river and its associated environment.  This report is an update on what District staff has learned in regard to the concerns of various parties and the technical and regulatory requirements that would apply to various options for increasing the reservoir capacity.


RECOMMENDATION:  The Board should receive staff’s presentation, and open the meeting to the public for comment.  If the Board wishes further action by staff, the Board should provide direction as to what action is desired.


BACKGROUND:   At the February 28, 2008 Board meeting, the Board approved a request by Director Brower to direct staff to prepare, for review at a future Board meeting, a report regarding the feasibility of increasing the height of the existing Los Padres Dam.  Staff presented a report on three basic options for increasing reservoir capacity to the Board for the April 21, 2008 meeting (see Exhibit 26-A, the staff note for that item, and Exhibit 26-B, a memorandum report by District Engineer Andrew Bell dated April 7, 2008).  The Board directed staff to confer with NOAA Fisheries, California Department of Fish and Game, and California America Water regarding a potential project to increase the capacity of Los Padres Reservoir.


Los Padres Dam, constructed in 1948 and 1949 by California Water and Telephone, a predecessor of California American Water, is an embankment dam (zoned earthfill) approximately 150 feet high.  It is located on the Carmel River at River Mile 24.8, approximately 12 miles southeast of Carmel Valley Village near the settlement of Princes Camp.  When built, the reservoir had a capacity of 3,030 acre-feet, but due to accumulation of sediment, the storage capacity has decreased to approximately 1,770 acre-feet. 


Increasing the height of the dam would require extensive engineering, geotechnical, and planning efforts.  In order to evaluate the technical feasibility of this project, the District would need to retain experts in dam construction and rehabilitation.  A summary of factors to consider is provided in Exhibit 26-B.  Two alternatives to increasing the height of Los Padres Dam that could be considered are also described in this report:  (1) sediment that has accumulated in Los Padres Reservoir could be removed; and (2) an inflatable dam could be installed in the existing spillway and raised to create additional storage space when it is deemed safe to do so.


Activities and Findings Since April 21, 2008 Board Meeting

Since the April 21, 2008 Board meeting, District staff has contacted the following entities to learn their concerns regarding projects that would increase the storage capacity of Los Padres Reservoir:


National Marine Fisheries Service (NOAA Fisheries)

California Department of Fish and Game (CDFG)

California American Water (CAW)

California Department of Water Resources, Division of Safety of Dams (DSOD)


The federal and state resource agencies, NOAA Fisheries and CDFG, have been working with CAW and others regarding means to improve fish passage at Los Padres Dam, primarily downstream passage for steelhead.  NOAA Fisheries and CDFG would be generally supportive of increasing storage capacity in the reservoir to enhance instream flows, but any project would need to incorporate or facilitate fish passage improvements.  District staff have asked for input from NOAA Fisheries and CDFG, but no specific comments on any of the options have been provided by these agencies to the District to date.


CAW, as owner of the dam, would need to be in agreement with any modifications to the dam or with a dredging project.  CAW General Manager Craig Anthony has indicated CAW has no interest in raising the dam or spillway elevation to increase storage capacity.


In CAW’s General Rate Case application for 2009, 2010, and 2011, CAW proposed approval of $200,000 for a dredging feasibility study for Los Padres Reservoir.  The November 2008 settlement agreement between CAW and the Division of Ratepayer Advocates includes agreement on a slightly inflated cost for this work, and the recent proposed decision by the Administrative Law Judge in the General Rate Case proceeding includes approval of the settlement agreement.  CAW’s schedule for this work was to begin in January 2009 and finish in December 2009, but CAW has yet to begin the study.  CAW General Manager Craig Anthony has stated that no work has been done on the dredging feasibility study because of delays in finalizing the decision on the General Rate Case application.


Staff contacted staff of the California Division of Safety of Dams (DSOD) by telephone and by letter dated April 8, 2009 (Exhibit 26-C)to learn what concerns they may have regarding three options for increasing the reservoir capacity and what the process for obtaining the needed approvals to modify the dam or spillway.  David Gutierrez, Chief of DSOD, responded with a letter dated May 1, 2009 (Exhibit 26-D).  Staff has scheduled a follow-up meeting with DSOD staff for June 26, 2009 in Sacramento, and CAW has been invited to attend.  CAW General Manager Craig Anthony has stated that he does not plan to attend the meeting.


MPWMD staff also met with an engineer on the staff of Monterey County Water Resources Agency and one of their consultants regarding that agency’s project to modify the spillway at Nacimiento Dam.  Several features of that project apply to the option for Los Padres Dam of installing an inflatable dam in the spillway to allow seasonal storage of water. District staff reviewed three of the consultant reports for the project:  hydrology for probable maximum flood and routing through the reservoir, seismic stability review of the spillway and adjacent embankment materials, and a geotechnical investigation of the dam and spillway and adjacent area.  These are the type of studies that are required by DSOD to demonstrate that a proposed addition or modification to a dam meets their stringent safety standards.


Pursuit of any of the options would require environmental review.  CEQA (California Environmental Quality Act) would apply in all cases.  NEPA (National Environmental Policy Act) would apply if any of the work were deemed to involve dredge or fill in “waters of the United States” (the Carmel River is in this category), or to affect steelhead or California red-legged frogs, species listed as threatened under the federal Endangered Species Act. 




26-A    April 21, 2008 staff note for item titled “Review Procedure and Timeline for Conducting a Feasibility Study of Increasing the Height of the Existing Los Padres Dam to Increase Its Water Storage Capacity”

26-B    April 7, 2008 Memorandum Report by Andrew M. Bell, MPWMD District Engineer

26-C    April 8, 2009 letter from Andrew M. Bell, MPWMD District Engineer, to David Gutierrez, Chief, Division of Safety of Dams, California Department of Water Resources

26-D    May 1, 2009 letter from David A. Gutierrez, DSOD, to Andrew M. Bell, MPWMD