Tumwater Dam

Tumwater Dam in 1998.

Located 25 highway miles east of Berne, in the Tumwater Canyon, this dam was built by the Great Northern Railway to produce the electricity for the electric locomotives that pulled trains through both Cascade Tunnels.

Tumwater Dam in 1998.

The Great Northern mainline went down Tumwater Canyon and past this plant until 1928, when the new Chumstick Line was opened that bypassed the canyon and was shorter and straighter with less grades.

Tumwater Dam in 1998.

The city of Leavenworth was also bypassed, leaving the town virtually isolated until U. S. Highway 2 was built through Tumwater Canyon, directly on the roadbed of the Great Northern's original route, where it remains today.

Tumwater Dam in 1998.

A sign at the dam explains its historical significance.

Tumwater Dam Sign in 1998.

HISTORIC TUMWATER DAM

The Tumwater Hydroelectric Project was constructed from 1907 to 1909.  At that time, the hydroelectric project was the largest west of Niagara Falls.  The project was constructed by the Great Northern Railway Company to produce power for electric locomotives traveling through the old Cascade Tunnel on the Stevens Pass route.

Electrification of the three miles of the 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 trolley line to pull passenger and freight trains through the tunnel, which was abandoned in 1929 upon construction of a new eight-mile-long Cascade Tunnel.  The locomotives were the first in the United States to utilize the principle of 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 Hydroelectric Project was closed in 1956.  By that time, the railroad had converted to diesel engines.  The project was purchased by the Chelan County public Utility District in 1957.  The powerhouse 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.

HISTORIC PROJECT STATISTICS

DAM
    Groundbreaking............July 6, 1907
    Length...........................400 Feet
    Height...........................23 Feet
    Construction Cost.......$100,000
    Fishway........................Newly Constructed 1987
HEAD..............................200 Feet
PENSTOCK
    Material.......................Wood & Steel
    Length.........................11,654 Feet
    Diameter.....................8.5 Feet
SURGE TANK
    Height.........................210 Feet
    Capacity......................1 Million Gallons
POWER HOUSE
    Generators..................Three, 2,000 kilowatts each 25 Cycle, A.C.
    Turbines......................Three, Francis type 4,000 horsepower each

Historical Photo:
Great Northern Tumwater Powerhouse, circa 1908 (UW)

East of Leavenworth, Highway 2 meets up with the railroad again, which returns to its original alignment through Wenatchee to Spokane and beyond. From this point on, there isn't much of historical interest to non-rail enthusiasts along the route for quite a distance beyond Stevens Pass, so that concludes this expedition.