The Portland District, U.S. Army Corps of Engineers (USACE) operates and maintains 13 multipurpose dams, reservoirs, and hatchery programs across Oregon's Willamette River Basin. Management of the Willamette Valley System for its authorized purposes necessitates ongoing and future operation of the system and maintenance at any given project. Operation and maintenance must respond to changes in Willamette River Basin conditions as well as to new information related to system operations and technology, the affected environment, policies, and regulations such as the Endangered Species Act (ESA).

The most recent National Environmental Policy Act (NEPA) evaluation for the overall Willamette Valley System operations and maintenance program was completed in a 1980 Environmental Impact Statement (EIS). Since then, operations have been modified and structural improvements for fish passage and temperature control have been implemented to address effects of the Willamette Valley System on ESA-listed fish. NEPA evaluations since the 1980 EIS have been project-specific. There is also new information relevant to the environmental impacts of operating the Willamette Valley System that USACE considers in this Draft EIS.

USACE has re-initiated formal consultation under Section 7 of the ESA on the National Marine Fisheries Service’s 2008 Biological Opinion for the Willamette River Basin Flood Control Project. This NEPA process will inform the ESA Section 7 consultation process.