Nearly 100 years ago there existed The Tumwater Hydroelectric Project. Construction began in 1907 and the plant started to produce electricity in 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.
From the Tumwater Dam located 2 miles upstream, water was delivered through a penstock to the powerhouse. 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 powerhouse was a concrete and brick structure that housed three Francis turbines 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 powerhouse and related generating facilities were subsequently removed.
The parking area is where the old powerhouse once stood. Before heading to the cache, take a good look at the black and white picture below and locate the following:
1) Three intake support structures. The penstock trifurcated into seperate inlets for the three Francis turbines at the back side of the powerhouse. These three intake support structures were lined with red brick (still existing).
2) Now locate the large boulder shown in the photo near the corner of the powerhouse. This is quite a large boulder and gives you an idea of the size of the powerhouse.
3) Near the entrance of the parking area, the large concrete structure at the corner is where the 210 foot tall surge tank once stood. The head elevation between the dam 2 miles upriver and the powerhouse was 200 feet.
4) Near the rivers edge, locate the riverside foundation of the powerhouse.
Now follow the trail which starts at the large boulder. As you can see, the top half of the steel penstock was removed, and the bottom half is now a walkway across the bridge and the Wenatchee River. The penstock is 8.5 foot diameter. You'll find the cache at the other side of the river. The trail continues along the river for 2 miles ending near the Tumwater dam. This trail was the path of the penstock as it delivered hydro energy to the powerhouse.
Here is an old photo showing the bridge, penstock, powerhouse, and surge tank.
Hope you enjoyed this bit of local hydroelectric history.
The Navigatorz
