North Fork Powerhouse and Fish Passage Facility complete

Tacoma Power built a new powerhouse and innovative fish collection and transportation system at Cushman Dam No. 2. The unique facility uses water discharged from turbines to attract migrating adult fish into a collector. Tacoma Power worked in partnership with the Skokomish Indian Tribe and natural resource agencies to design the facility. 

This new source of hydroelectric power serves 1,700 Northwest homes and captures energy from previously untapped water flows. 
 

The new fish collection and transportation facility:

  • Supports the establishment of endangered salmon and steelhead populations upstream of the project
  • Re-opens fish passage on the North Fork Skokomish
  • Collects migrating adult fish at the base of the dam and transports them to the top of the dam
  • Provides space and equipment for sorting migrating juvenile fish and transports them to the base of the dam for release

 The new powerhouse:

  • Provides 3.6 additional megawatts of clean, renewable hydropower
  • Recovers energy from water released into the North Fork Skokomish River for fish and habitat
  • Creates a 14% increase in generation capacity for Cushman Dam No. 2 

How do the new fish passage facilities work?
Adult fish migrating up the North Fork of the Skokomish River enter through the slot on the lower left of the diagram. They will be attracted by the water discharged from the new turbines. (Arrows show direction of water flow.)
 
adultfishtrapdiagram_500x449.jpg

More about adult fish passage
Once in the trap, fish will be moved into a transport hopper and lifted to the top of the dam on a tram. There the new fish handling system will be used to separate, count and mark (as necessary) the fish. We will transport the fish to their final destination upstream of the two Cushman dams.

Juvenile fish passage
To help migrating juvenile fish around the dams, Tacoma Power is building a new floating fish collection facility for Lake Cushman. This large floating device is under construction and expected to be installed in late 2014. It will be attached to Cushman No. 1 Dam. 

Collected smolts will be released in the North Fork Skokomish River at the base of Cushman No. 2 Dam to continue their migration.

Construction photos - North Fork Powerhouse and Fish Passage Facility

towercranecushmanno2_250x418.jpg

Erecting tower crane at Cushman No. 2 Dam

installingcofferdam_350x209.jpg

Installing a cofferdam to contain sediment and elevated pH water during concrete pours


blastingmats_350x209.jpg

Blast mats


excavationphfishcollection_350x209.jpg

Final excavation for powerhouse and fish collection facility

framefishcollection_350x209.jpg

Swinging in frame to construct fish collection facility above water on platform


fishcollectionplatform_350x209.jpg

Fish collection facility being constructed on platform 

 

fishcollectionconstruction_350x209.jpg

Fish collection facility construction


fishcollectionframe_350x209.jpg

Fish collection facility prior to jacking frame installation

 

fishcollectionfacilitylowered_350x209.jpg

Fish collection facility lowered into position


Hatcheries

Tacoma Power is designing two new hatcheries as part of the Cushman Hydro Project license and is working with a team to guide the design. The team includes representatives of:
  • Tacoma Power
  • Skokomish Tribe
  • Washington Department of Fish and Wildlife
Sockeye Hatchery
Tacoma Power's sockeye hatchery will be located adjacent to Skokomish Park at Potlatch. Once the hatchery is operational, it will raise two million sockeye each year.

The fry will be released in Lake Cushman, and smolts will be collected and released into the lower North Fork Skokomish River. Returning adult sockeye will eventually be collected at the base of Cushman Dam No. 2.

Hatchery construction is planned to be started in spring 2014.

Salmon and Steelhead Hatchery
This hatchery will be located at Lake Kokanee and will raise:
  • 375,000 spring Chinook fingerlings and yearlings
  • up to 35,000 coho smolts
  • up to 15,000 steelhead smolts
Hatchery construction is planned to be started in spring 2014.
 
To help migrating juvenile fish around the dams, Tacoma Power is building a new floating fish collection facility in Lake Cushman. Collected smolts will be released in the North Fork Skokomish River at the base of Cushman No. 2 Dam to continue their migration.

Recreation improvements
More camping opportunities will be coming to Big Creek Campground, a U.S. Forest Service campground near Lake Cushman, in the coming years.

Tacoma Power has plans in the works to construct more than 40 new RV and tent campsites, two kitchen shelters and interpretive and biking trails at the campground. We will also add a new water system.

Other improvements are planned for the day-use recreational sites along Staircase Road, Mount Rose trailhead access road and parking area, and Bear Gulch day-use site.