Pardee Reservoir Enlargement Project

The East Bay Municipal Utility District (EBMUD) needed to evaluate ways to increase the District’s water supply and storage capacity to meet the region’s growing demands and to provide a greater level of drought security.

One of the storage options identified involved raising of the Pardee Dam to provide up to 300,000 acre-feet of additional storage in the Pardee Reservoir.

GEI provided engineering and permitting services for the proposed reservoir enlargement, as part of a team with HDR Engineering and Christensen Associates. The team’s services included conceptual and preliminary design up to the 30% level; permitting and licensing support; and stakeholder issue resolution.

GEI’s role included design of modifications to Pardee Dam, the main spillway, and the Jackson Creek arm retention structures to enable them to retain a reservoir level up to 100 feet above the existing level.

Our work included supervision of all geotechnical, geological, and foundation design work; materials and roller-compacted concrete (RCC) mix design engineering; dam safety; spillway design; and regulatory interface.

The proposed 100-foot raise of an existing concrete gravity dam with RCC, for which GEI developed the conceptual designs, was unprecedented.