Spruce Falls Temporary Power Plant

Photos by John Hattie, courtesy of Allen Hattie.

Construction power requirements were met by the installation of two 1,250 H.P. units at Spruce Falls on the Swan River, 13½ miles down river. They were ultimately intended for use at Island Falls.

Work on the temporary plant was begun on October 4th, 1928. At Island Falls, interim electricity was provided by two four KW gasoline driven DC generators. Power was delivered from Spruce Falls on March 28th, 1929, and continued until No. 1 unit at Island Falls took over the load on June 8th, 1930.

This is one of two 1250 HP units (generators) installed in the winter of 1928 at Spruce Falls for generating power to supply the development at Island Falls 14 miles upstream.
Transmission line 1/2 mile from the temporary power plant at Spruce Falls.
The generators, each of the vertical type, were installed in a frame building and developed power at 550 volts to a bank of outside transformers rated at 2,000 K.V.A. which stepped up the voltage to 26,400 for transmission to Island Falls where it was stepped down to 2200 and 550 for distribution.
Water to the turbines was delivered through two seven-foot diameter, wood-stave penstocks, each 90 feet long.
Power house exterior.
A fifteen foot timber dam was constructed at the point where the river empties into Duck Lake, impounding a small forebay. This, together with the natural fall of 25 feet, produced a forty foot head of water.
Immediately above this head water a timber crib dam was built in order to regulate storage and prevent waste as it was apparent that water would be scarce, even so, in 1930 low water level made it necessary to find additional sources of water. The outlet of Barrier Lake was cut through and the 55 square miles of water was lowered six feet in order to supply sufficient power for the work at Island Falls.