Aspen has provided a variety of environmental services to the USACE for the Santa Ana River Mainstem Project. The Santa Ana River Mainstem Project is a major flood control project spanning 75 miles along the Santa Ana River – from the upper canyon in the San Bernardino Mountains downstream to the Pacific Ocean at Newport Beach.

Aspen prepared an Environmental Assessment and supporting documents, including a Biological Evaluation/Biological Assessment and Management Indicator Species Report, for the proposed Lincoln Avenue Water Company (LAWC) Project located entirely within the boundaries of the Angeles National Forest.

Aspen was selected by the California Public Utilities Commission (CPUC) to undertake the CEQA environmental review for two applications for Certificates of Public Convenience and Necessity filed by Southern California Water Company (SCWC).

Because the potential for flooding along the Santa Paula Creek channel is considered life threatening, the USACE began construction of the flood control channel at Santa Paula Creek in June 1997.

Under contract to California Trout and in partnership with California Department of Parks and Recreation (CDPR), Aspen prepared the Rindge Dam Removal Pathway Risk-Benefit Assessment.

Under contract to the California Department of Water Resources (DWR), Aspen Environmental Group prepared an Environmental Impact Report (EIR) for a proposal to change the seasonal flow release schedule of Pyramid Dam, located at the southern end of Pyramid Lake in Los Angeles County, California.