WATER SUPPLY PLANNING COMMITTEE

ITEM:		ACTION ITEMS
5.	UPDATE ON STATUS OF CARMEL RIVER REROUTE/SAN CLEMENTE DAM REMOVAL PROJECT
Meeting Date:			May 4, 2011
From:			Darby Fuerst,
			General Manager
Prepared By:			Larry Hampson

SUMMARY: MPWMD Senior Water Resources Engineer Larry Hampson attended a Technical Review Team (TRT) meeting on April 6, 2011 at the Oakland office of the California Coastal Conservancy. MPWMD Senior Fisheries Biologist Kevan Urquhart called in to the meeting. The focus of the meeting was to review and comment on revised concepts for several components of the project and to set a schedule for review of final design documents (see Exhibit 5-A, will be presented at May 4, 2011 committee meeting). MPWMD had previously raised concerns about the permeability of the diversion dike that would be constructed to divert flows into the San Clemente Creek arm of the reservoir. The refined approach is to create an impermeable soil-cement barrier across the existing main stem by auguring down through the sediments to bedrock and injecting cement as holes are drilled. MPWMD had also raised concerns with the previous design concept about the retention of groundwater in the sediment stockpile. The refined concept is to excavate the downstream end of the sediment stockpile (just upstream of the existing dam) and backfill with fractured bedrock removed from the ridge between the main stem and the San Clemente arm of the reservoir. With these proposed changes, the fractured rock and porous sediments near the bottom of the reservoir would likely not be a barrier to groundwater flows. Both of these refinements would likely address the concerns about groundwater movement after project completion.

MPWMD had also raised a concern about maintaining fish passage from the rerouted main stem channel into San Clemente Creek. The consultants for the project propose to extend improvements to San Clemente Creek further upstream and will carry out additional analysis concerning fish passage and channel stability.

The TRT is tentatively scheduled to review initial construction plans in June 2011. A quarterly meeting of the project stakeholders was scheduled for April 29, 2011. Staff will provide a summary of the stakeholder meeting at the Water Supply Planning Committee meeting on May 4, 2011.

EXHIBITS

5-A TRT Meeting No. 1, Concept Refinement & Design Criteria, April 6, 2011 Presentation (Will be presented at May 4, 2011 committee meeting)

U:\staff\word\committees\WaterSupply\2011\20110504\05\item5.docx:\