Post Falls HED South Channel Dam Rehabilitation

Spokane River near Post Falls, ID: Gate replacement and concrete rehabilitation of the 100 year old South Channel Dam at the Post Falls Hydroelectric Development.

Project Details

Post Falls HED consists of three separate dams, the South Channel and North Channel Dams are necessary for spill control of the Spokane River, with power being generated at the Middle Channel Dam. Kuney constructed a temporary 48-foot diameter cellular cofferdam and two approach cofferdam structures. In total, the temporary dam is 90-feet long, 30-feet tall, and holds back the Spokane River allowing Kuney to rehabilitate the dam in the dry. The project was successfully built with the utmost concern for the environment and is under a very tight schedule. The access, environment and schedule made this relatively small project one of Kuney’s most challenging to date.

Project specs

  • Location: Post Falls, Idaho on the Spokane River
  • Owner: Avista Utilities
  • Timeframe: 2014-2015
  • Size: Private (Over $5 Million)
  • 600 CY of concrete demolished, followed by consolidation grouting, and approximately 600 CY of reinforced concrete upstream and downstream of the dam.
  • Total replacement of all six gates under extremely tight tolerances.
  • Dredging and extensive diver work required for cofferdam preparation.


  • 2016 Build Northwest Award for Construction Excellence - Inland NW AGC