Environmental Consulting

Metropolitan Water District Inland Feeder | San Bernardino County, CA

Metropolitan Water District of Southern California


Biological Monitoring
Hydrological Monitoring
Resource Mapping
Biological Resource Surveys
Agency Coordination

Hydrological and Biological Resource-Monitoring Program

The Metropolitan Water District’s Inland Feeder Project is a high-capacity water delivery system designed to increase California’s water supply. It consists of nearly 44 miles of tunnels and pipelines that pass through the foothills of the San Bernardino Mountains to the Colorado River Aqueduct. The $1.2-billion project provides up to 650 MG of water per day to water users within MWD’s 5,200 square-mile Southern California service area.

Psomas designed and implemented a hydrological and biological resource-monitoring program to detect and evaluate changes to hydrologic conditions resulting from construction and operation of the conveyance system. This program included site visits to springs, streams, and domestic wells located in rugged terrain only accessible by helicopter.

Psomas collected and managed biological data to assess the health of riparian and wetland vegetation potentially affected by loss of surface water and groundwater from the construction project. Psomas also conducted repeated protocol surveys for two endangered bird species in the area, the southwestern willow flycatcher and the least Bell’s vireo. Psomas monitored, assembled, and organized the Administrative Record of Compliance with all CEQA and NEPA mitigation.