Water Rights Permitting for Cushman Hydroelectric Project

Helping Tacoma Power process and win water rights applications for activities at Cushman Hydroelectric Dam.

One of the first major dams in the Pacific Northwest, the Cushman Hydroelectric Project, created two dams on the North Fork of the Skokomish River in the 1920s to provide power to the surrounding area. As part of a Federal Energy Regulatory Commission (FERC) relicensing term and a settlement agreement for the use of the dams until 2048, Tacoma Power, along with other entities such as the Skokomish Indian Tribe, were required to work with the Washington State Department of Ecology to secure all needed water rights. GeoEngineers processed 11 water rights applications, including applications for surface and reservoir water. One of the groundwater right applications was for more than 3,100 gallons per minute to support fish-propagation activities.


With a complex settlement agreement, GeoEngineers’ main challenge was to understand how the settlement agreement related to the water right application process. Our methodology for processing the 11 applications included:

  • Completing a Phase 1 analysis that established the universe of competing water rights for each application.
  • Examining numerous technical references and settlement agreement documents related to the project.
  • Analyzing streamflow data from three U.S. Geologic Survey gaging stations on the North Fork Skokomish River.
  • Visiting the site to verify well locations and facilities.
  • Evaluating the four-part test that is conducted for each water right application: 1) the water must be available, both physically and legally; 2) there must be no impairment of existing senior water rights; 3) the water must be put to beneficial use; and 4) the water use must not be detrimental to the public interest.
  • Completing 11 Reports of Examination for Ecology that officially documented the water rights analysis.


GeoEngineers produced 11 concise and accurate Reports of Examination that were compatible with the settlement, as well as the state’s water right process and the applicant’s needs. Ecology processed and permitted all 11 applications for use.

Related Projects


Questions? We have answers.