Tumwater Dam
Posted by: 
Ambrosia
N 47° 37.011 W 120° 43.358
10T E 671131 N 5276228
Tumwater Canyon, near Leavenworth, WA
Waymark Code: WMXN4
Location: Washington, United States
Date Posted: 11/05/2006
Views: 92
The Tumwater Hydro Electric Project was constructed from 1907-1909. At that time, the hydro electric project was the largest west of Niagara Falls. The project was constructed by the Great Northern Railway Company to produce power for the electric locomotives traveling through the old Cascade tunnel on the Steven's Pass route.
Electrification of the three miles of line brought an end to the serious smoke and gas conditions in the tunnel resulting from the coal burning locomotives. Four 100-ton electric locomotives were in service on the trolly line to pull passenger and freight trains though the tunnel, which was abandoned in 1929 upon the construction of the new eight-mile-long Cascade Tunnel. The locomotives were the first in the United States to use regenerative braking, returning power to the lines on the downhill grade.
From the Tumwater Dam, water was delivered through a penstock to a powerhouse over two miles downstream. A bridge was constructed across the river to allow railroad access to the dam construction site. The bridge was then utilized to carry the penstock to the powerhouse. The bridge still stands and serves as a link to the old penstock route. The powerhouse was a concrete and brick structure that housed three waterwheels and three 2,000 kilowatt generators.
The Tumwater Hydro Electric Project was closed in 1956. By that time, the railroad had converted to diesel engines. The project was purchased by Chelan County Public Utility District in 1957. The powerhouse and related and related generating facilities were subsequently removed.
The Tumwater Dam is now equipped with modern fish passage facilities to assist adult salmon and steelhead returning to their spawning grounds.