Long Lake Dam Overlook - Tumtum, WA
Posted by: 
T0SHEA
N 47° 50.405 W 117° 50.423
11T E 437117 N 5298868
The Long Lake Dam and hydro station impounds the Spokane River about 15 miles north west of the city of Spokane, WA. Though it can be viewed from below, this is the best place to view the dam and the lake.
Waymark Code: WMJYG6
Location: Washington, United States
Date Posted: 01/16/2014
Views: 7
This overlook is a great place to view the dam and powerhouse, as well as the lake above and the river below. A great time to view any dam is in the spring when the river's flow is at its greatest and they're spilling a lot of water. A bonus here for birdwatchers is the fact that ospreys nest on the power poles nearby. There are several informational signs at the viewpoint. It's certainly not handicap accessible as there are several steps to navigate in order to get down to the viewpoint from the parking area.
To get here, take Highway 291 from the northwest corner of Spokane past Tumtum until you see the sign. It's a total of 26 miles from Spokane. Alternatively, take Highway 231 just over 15 miles north from Reardan, WA.
Completed in 1915, the spillway dam is 400 feet long, 250 feet thick at the base, and 208 feet from foundation to crest. It is constructed of concrete on a base of solid rock. The headgate dam is 240 feet long, 100 feet high and 100 feet thick at the base. The third arch, or cutoff dam, is 540 feet long, 100 feet high and 50 feet thick at the base. When built, the spillway dam was the tallest of its type in existence.
The dam creates a head of 170 feet, and impounds 2,695,000,000 cubic
feet of water. This is sufficient to make it a storage, as opposed to run of the river hydro project. There are four 236 foot long, 16 foot diameter penstocks to supply water under a head of 170 feet to the turbines.
The turbines are direct connected to 13,900 KVA General Electric generators. The total output of the powerhouse is 55.6 Megawatts. The powerhouse is a Romanesque Revival style structure with a concrete foundation, steel frame, brick exterior, and concrete roof. The generator room measures 75 feet by 160 feet and is 65 feet high.
In order to build this large and labour intensive project, a temporary town large enough to house 800 to 1,000 people was built and a 22 mile railway spur was constructed to move all machinery and supplies to the site.
The Long Lake Dam is now a National Historic Place.
The Long Lake Hydroelectric Power Plant is historically and architecturally significant as a reflection of advanced hydroelectric technology, as the largest generating facility of Washington Water Power for many years, and as an architecturally distinctive example of
industrial design from the period. The innovations represented by the plant are remarkable: the height of the dam surpassed all other spillway structures when it was completed in 1915; the use of rolling gates represented the first American application of an evolving technology; and the 25,000 hp inward flow reaction type Francis turbines had the largest output capacity in the world. In addition, the Romanesque Revival character of the powerhouse, with its arched fenestration and battlemented parapet, is a dramatic example of its type and period. Over the years there have been few changes to the Long Lake facility, and no single element has been so compromised that the integrity of the entire system has been lost. As a result, the plant meets the registration requirements of the Hydroelectric Power Plants in Washington State multiple property documentation form.
Historical Background
Prior to the completion of Washington Water Power's Little Falls plant, it became evident that the new facility could not meet the escalating power load demands of the Inland Empire. Thus in 1910, the company began work on its largest and most ambitious undertaking. During that year it acquired the Long Lake power station site from the Big Bend Water Power Company, and developed plans for construction of a generating facility whose capacity would be four times that of the Little Falls plant.
From the National Register
Coordinates given are for the parking lot above the the viewing area.
