Environmental Assessment. 2015 Lower Klamath River Late-Summer Flow Augmentation From Lewiston Dam

This Environmental Assessment (EA) examines the potential direct, indirect, and cumulative impacts to the affected environment associated with the Bureau of Reclamation proposal to release supplemental flows from Lewiston Dam to improve water quality and reduce the prevalence of fish disease in the lower Klamath River. The Proposed Action will be implemented in late summer of 2015 to support the health of salmonid fish, including species that return to the Trinity River Basin to reproduce. The area of potential effect includes Trinity Reservoir and the Trinity River from Lewiston Dam to the confluence with the Klamath River, and the Klamath River to the Klamath River estuary near Klamath, California. Additionally, the affected environment includes the Sacramento River Basin as transbasin diversions from Trinity Reservoir via Lewiston Reservoir and the Clear Creek Tunnel to the Sacramento River Basin have occurred historically and are planned to occur throughout the summer (see Figure 1). This EA was prepared in accordance with the National Environmental Policy Act (NEPA), Council of Environmental Quality (CEQ) regulation (40 CFR Parts 1500-1508), and Department of the Interior Regulations (43 CFR Part 46).