Since 1990 Tetra Tech has supported the U.S. Army Corps of Engineers (USACE) to maintain and improve the Bonneville Lock and Dam, a National Historic Landmark completed in 1938. This major source of hydroelectric power was a Public Works Administration project, part of President Franklin D. Roosevelt’s New Deal.

Tetra Tech services include a variety of structural, mechanical, electrical, civil, and fisheries engineering at Bonneville Dam for USACE. Scopes of work have included preliminary and final design, inspection services, and cost estimating for a wide range of project elements.

Recent projects completed at Bonneville Dam include:

  • Plans, specifications, and construction support for lamprey passage at Washington Shore fish ladder to allow this species to cross the dam without compromising the salmon passage
  • Plans, specifications, and cost estimating services for lock control system replacement
  • Electrical, structural, and mechanical engineering and cost estimating services for spillway gate full-flow hoist; by replacing the unsafe process of removing the hoist and gate by gantry crane with vertical lift, gates can be removed from flows during floods
  • Design services for rehabilitating aging spillway gate hoists to improve the life of the hoists for an additional 20 years
  • Hydroacoustic surveys of the spillway stilling basin
  • Inspection and engineering services for the refurbishment of an 85-ton-capacity gantry crane
  • Design engineering report for wastewater improvements, including recommendations for treatment upgrades and strategies to manage domestic and fish hatchery sludge
  • Preparation contract documents to support a Request for Proposal effort for wastewater treatment plant upgrades
  • Assessment of the Bradford Island fishway conditions and recommendations for future repairs or replacement of the Bradford Island fishway; study results will also be used to budget funds for repairs and replacement
  • Development of a facilities plan for the wastewater treatment plant, including an innovative, cost-saving approach to equipment redundancy requirements for the plant’s oxidation ditch and clarifier using an existing aerobic digester as a standby aeration basin and clarifier