A one-time cash payment, a share of electric output and land transfers have been agreed as key parts of major claims settlement between US utility Tacoma Power and Skokomish Tribal Nation as part of relicensing the Cushman hydro power scheme in Washington state.

To settle the US$5.8B damages claim, the parties agreed to Tacoma Power making a US$12.6M one-time cash payment, providing a 7.25% share of output from the Cushman No2 plant, and transfer of land valued at US$23M.

Further key aspects of the licensing agreement settlement include river restoration, in-stream flows, fisheries and recreation.

The settlement will licence the Cushman facilities for another 40 years, subject to approval by the Federal Energy Regulatory Commission (FERC).

The Cushman scheme on the Skokomish river, in Mason County, comprises two dams and powerhouses: No1 Dam, which is 339m long and impounds Lake Cushman, was completed in 1926 and generates approximately 127GWh of electricity annually; the No2 Dam, which is 175m long, impounding Lake Kokanee, was finished in 1930 and produces 233GWh per year.

The original, 50-year federal licence for the scheme expired in 1974 and until 1998 the utility has operated the facilities under short-term licences. A broader licence was issued in 1998 and the new settlement will modify the licence.

Mediation was used to start talks towards a settlement, and both state and federal agencies joined the negotiations a year and a half ago. Last month, Tacoma Public Utilities Board authorised the proposed licensing settlement, and Tacoma City Council authorised the proposed damages settlement.