Environmental Consulting

Gem Lake Geomembrane Installation | Inyo County, CA

Southern California Edison


Permit Compliance
Pre- and Post-Construction Monitoring
Riparian Habitat Monitoring
Hydroelectric Project
Agency Coordination

Riparian Monitoring and Permit Compliance

Psomas worked with Southern California Edison (SCE) staff to develop the permitting package for their Gem Lake Dam Geomembrane Installation. Gem Lake Dam, located on Rush Creek in the Inyo National Forest and Ansel Adams Wilderness Area, had exhibited increasing instances of leakage. SCE installed a geomembrane liner on the upstream face of the dam to prolong the life of the dam and prevent/minimize leakage. To minimize potential impacts, the project required completion in one season between snowmelt and snowfall.

Psomas worked with SCE to develop a U.S. Forest Service Wilderness Minimum Tool Analysis, a Section 404 Nationwide Permit application, a Section 401 Certification application, a Streambed Alteration Agreement, a Biological Assessment, and a CEQA Categorical Exemption. Psomas maintained close communications with the permitting agencies and SCE during the process. Psomas also conducted construction monitoring.