Priest Rapids Dam Juvenille Fish Bypass

Columbia River near Mattawa, Washington: A unique fish bypass project requiring spillway and gate modifications.

Project Details

The Priest Rapids Fish Bypass is critical to helping Grant County PUD reach its goal of a 95% survival rate for juvenile fish passing the dam. Kuney-Goebel JV modified spillways 20, 21 and 22 to increase the cress elevation and remove the downstream flip-lip. These modifications allow juvenile fish to slide over the dam at an increased survival rate, decrease the amount of dissolved oxygen in the Columbia River, and allow for greater power production. Extensive barging was required for both upstream and downstream access. As part of the project, the team also modified the over/under gate 22 so that it would function properly with the new raised spillway. The lower 35' of the gate and two arms were removed, the remaining arms stiffened, and gate seals replaced. Max J. Kuney Co was the managing partner for Kuney-Goebel JV.

Project specs

  • Location: Columbia River, Washington
  • Owner: Grant County PUD
  • Time frame: 2011-2015
  • Size: $27.3 Million
  • Over 17,000 CY of tremie, mass and reinforced concrete placed.
  • Tailrace bulkheads installed to dewater all three bays.