Project Description
The Lake Fordyce Dam Seepage Mitigation Project aims to repair the dam and bring it into compliance with the California Department of Water Resources, Division of Safety of Dams (DSOD) seepage threshold of 30 cubic feet per second (cfs). The project involves placing an impermeable membrane liner on the dam’s upstream face, constructing a new concrete plinth and grout curtain at the upstream toe, and installing a rockfill cofferdam with a rock buttress and membrane liner. The project also includes developing two local quarry areas for rock sourcing, implementing a pH containment and management system, and improving Lake Fordyce Road for construction access.
Major Challenges
Project Highlights
Project Scope
The scope of the Lake Fordyce Dam Seepage Mitigation Project is comprehensive and multifaceted. It includes the installation of an impermeable membrane liner on the dam’s upstream face and the construction of a new concrete plinth and grout curtain at the upstream toe. A key component is the building of a rockfill cofferdam with a rock buttress and membrane liner to create a dry work area. The project involves dredging approximately 4,100 cubic yards of reservoir sediments and developing two local quarry areas for rock sourcing. An important aspect is the implementation of a pH containment and management system to ensure water quality standards are met. The scope also includes improving Lake Fordyce Road for construction access and maintaining a minimum flow release of 5 cfs into Fordyce Creek during construction. The project is set to be executed over up to five non-consecutive construction seasons, allowing for flexibility in response to weather conditions. Throughout all phases, the project will comply with state water quality standards and environmental regulations, ensuring responsible execution of this critical infrastructure improvement.
