The Electron Hydroelectric Project, originally known as the Puyallup Project, is a

hydroelectric Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

power plant operated by Electron Hydro LLC on the

Puyallup River The Puyallup River ( ) is a river in the U.S. state of Washington. About long, it is formed by glaciers on the west side of Mount Rainier. It flows generally northwest, emptying into Commencement Bay, part of Puget Sound. The river and its t ...

Pierce County, Washington Pierce County is a County (United States), county in the U.S. state of Washington (state), Washington. As of the 2020 United States census, 2020 census, the population was 921,130, up from 795,225 in 2010, making it the second-most populous ...

. It generates of electricity and is operated and maintained by approximately 20 full-time employees.

Location

It is located along the Puyallup River near Kapowsin, Pierce County, approximately southeast of

Tacoma Tacoma ( ) is the county seat of Pierce County, Washington, United States. A port city, it is situated along Washington's Puget Sound, southwest of Seattle, southwest of Bellevue, northeast of the state capital, Olympia, northwest of Mount ...

and southeast of

Seattle Seattle ( ) is the most populous city in the U.S. state of Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the 18th-most populous city in the United States. The city is the cou ...

in the western foothills of

Mount Rainier Mount Rainier ( ), also known as Tahoma, is a large active stratovolcano in the Cascade Range of the Pacific Northwest in the United States. The mountain is located in Mount Rainier National Park about south-southeast of Seattle. With an off ...

Technology

The project, which was completed in 1904, draws water from the Puyallup River behind the Electron Diversion Dam, then funnels it to the Electron power plant via a span of wooden

flume A flume is a human-made channel for water, in the form of an open declined gravity chute whose walls are raised above the surrounding terrain, in contrast to a trench or ditch. Flumes are not to be confused with aqueducts, which are built to t ...

running along the side hills of the winding river valley while the river runs down a steep canyon. The wooden flume has a cross section of and can supply up to of water per second to the turbines of the Electron powerhouse. Original construction took approximately 14 months to complete. The grade is uniform and runs at seven feet of elevation per mile. A light railway line was built on top of the flume to shuttle maintenance workers and equipment. It is known as "the crookedest railway in the world," but it is not the only railway line with this claim. The flume and the railway were rebuilt in the 1940s, then again in 1985 on the original track. The original wood frames were replaced with over 12,000 steel frames, roughly on center. The flume is supported with over 6,000 bents. The flume is lined with 5.5 million board feet of fir. Electron Hydro, LLC is in the process of rebuilding the wood liner with Alaska yellow cedar and possibly coated with

Polyurea Polyurea is a type of elastomer that is derived from the reaction product of an isocyanate component and an amine component. The isocyanate can be aromatic or aliphatic in nature. It can be monomer, polymer, or any variant reaction of isocyanate ...

. It is notable for likely being the largest flume in use for hydroelectric projects in the United States.

Fish passage facilities

The upstream migration of spawning adult

salmon Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native ...

and

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributary, tributaries of the Pacific Ocean in North America and Asia. The steelhead (sometimes called steelhead trout) is an Fish migration#Classification, ...

is possible by a concrete,

fish ladder A fish ladder, also known as a fishway, fish pass, fish steps, or fish cannon, is a structure on or around artificial and natural barriers (such as dams, locks and waterfalls) to facilitate diadromous fishes' natural migration as well as mov ...

built alongside the wooden diversion dam opposite the flume intake. Migrating juvenile fish that inadvertently enter the wooden flume downstream will be captured alive and placed back in the Puyallup River using a trap-and-haul facility, which is located in the storage reservoir’s forebay.

Incidents

On July 29, 2020, Electron Hydro, the company that owns and operates the dam, experienced an industrial accident in which crumb rubber debris was released into the Puyallup River. Astro-turf used as part of a cofferdam broke loose from the HDPE liner and was spilled into the river. The company took immediate action to rectify the spill. In early May 2023, a Pierce County Superior Court Judge had approved a $1 million settlement in a criminal lawsuit brought by the state Attorney General’s Office over a 2020 spill of rubber into the Puyallup River during a construction project at the old wooden dam. The financial penalties for Electron Hydro were approved over the discharge of rubber that was torn loose from

artificial turf Artificial turf is a surface of synthetic fibers made to look like natural grass, used in sports arenas, residential lawns and commercial applications that traditionally use grass. It is much more durable than grass and easily maintained wi ...

the company used during a construction project. Chunks of the turf padding, made of ground-up tire rubber that is toxic to fish when ingested, were found as far as downriver after it was used without a permit to line a water-diversion channel. Electron Hydro Chief Operating Officer Thom Fischer pleaded guilty to a gross criminal misdemeanor and received a suspended jail sentence. The $1 million settlement included $745,000 in restitution to the Puyallup Tribal Fisheries and $255,000 in fines paid to Pierce County. In addition to the settlement with the Attorney General’s Office, Electron Hydro in 2021 was fined $501,000 by the state Department of Ecology for polluting the river. The company also installed a rock wall in 2020 which was supposed to be removed in 2021. Electron Hydro was ordered by the court in February 2024 to remove the center portion of the rock dam during the summer. The court ruled that the barrier harmed steelhead trout, Chinook salmon, and bull trout, which are protected under the

Endangered Species Act The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting and conserving imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...

References

External links

The Electron Hydropower Project website
* *{{HAER , survey=WA-12 , id=wa0187 , title=Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA , photos=89 , dwgs=6 , data=26 , cap=6 Historic American Engineering Record in Washington (state) Hydroelectric power companies of the United States Puyallup, Washington Light rail in Washington (state) Energy infrastructure completed in 1904 1904 establishments in Washington (state) Hydroelectric power plants in Washington (state) Puget Sound Energy Puyallup River