PUD releases license application for Enloe Dam

OKANOGAN – Okanogan County PUD has sent the Final License Application for Enloe Dam to the federal agency that oversees the licensing of dams.

Enloe Dam is located on the Similkameen River northwest of Oroville. Constructed soon after the turn of the last century, power production ceased in 1958. The previous powerplant, located 900 feet downstream from the dam could produce 3.2 megawatts. The PUD proposes moving the powerplant from the west to the east side of the river and generating a proposed 9 megawatts.

“The proposed 9.0 MW facility has a footprint that is about half the size of the existing facilities while providing nearly three times the generating capacity of the existing decommissioned plant and about twice the average annual energy output,” writes the electric utility in their application to the Federal Energy Regulatory Commission (FERC).

The proposal would also reduce the length of the river affected by diversion of a portion of the outflow from the reservoir through the powerplant. It would also return water only 480 feet downstream of the dam, while the old system returned water 930 feet downstream. This would provide for better circulation at a deep pool near the base of the falls which provides a cool water refuge for fish using the Similkameen River.

Enloe Dam is a concrete gravity arch dam constructed between 1919 and 1923 as part of the second power development constructed at Similkameen Falls. The dam is 315 feet long with a maximum height of 54 feet.

“The proposed project includes restoring the functionality of the flashboards on the crest of the existing spillway by retrofitting crest gates. These gates would be five feet high and would increase the water level upstream of the dam and the hydraulic head available for power generation,” says the application.

In 2000 FERC rescinded the district’s license and advised the utility that any future application should include a consensus of all responsible parties in the United States and Canada regarding fish passage. The PUD believes that the issue of fish passage, always a sticking point in restoring the dam to hydroelectric production in the past, will not hold back the project this go around. They indicate in their application that they have had extensive consultation with Indian tribes on both sides of the border, as well as the concerned agencies in the U.S. and Canada.

On Sept. 14, 2005 FERC granted a temporary permit for the project and that is why they prepared the current application for license

Copies of the Final License Application are available at the public libraries in Oroville, Tonasket, Omak, Okanogan and Twisp.