Electron Hydroelectric Project


The Electron Hydroelectric Project, originally known as the Puyallup Project, is a hydroelectric power plant operated by Puget Sound Energy on the Puyallup River in Pierce County, Washington. 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 and southeast of Seattle in the western foothills of Mount Rainier.

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 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.
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 fir. Electron Hydro, LLC is in the process of rebuilding the wood liner with Alaska yellow cedar and possibly coated with Polyurea. 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 and rainbow trout is possible by a concrete,
fish ladder 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.