A Hidden Gem of Hydropower

By Kristin Mettke

Tucked away along Lake Creek, just outside of Troy Montana, is NLI’s Lake Creek Hydroelectric Dam. Built in 1917 for a lumber mill, the dam has seen a number of improvements throughout the years. Many of the original structures have been well- maintained and are still in use.

The hydroelectric dam consists of a concrete gravity dam and a penstock that drops the water downhill to two powerhouses that generate power. In terms of hydroelectric dams in the region, it is small, generating less than 2% of the output of Cabinet Gorge Dam near Noxon, Montana.

Lake Creek Dam is a “run-of-river” dam, meaning NLI does not store any water to release at scheduled times or to hold for later in the summer. The water flow is whatever the natural flow of Lake Creek is, which is fed primarily from Bull Lake and other small creeks.

We are now in peak season for generation at the dam. Snow melting off the mountains and spring rains bring maximum flows through the penstock and some water gets “spilled” over the dam during spring runoff.

The dam produces power year-round. However, we typically have three to four months of higher generation in the spring and early summer.

About 10% of NLI’s power comes from Lake Creek Dam, a small portion comes from the community solar project at the NLI office in Sagle, and the rest is bought through the Bonneville Power Administration, which is primarily hydroelectric power.

Although Lake Creek Dam is small relative to other hydroelectric dams in the region, it requires many of the same regulations of the larger dams to ensure public safety and environmental compliance.

The Federal Energy Regulatory Commission has a regional office in Portland that oversees dams in the Pacific Northwest that meet certain size criteria, which Lake Creek does. It is important to ensure we are not unnecessarily endangering any wildlife such as fish, or putting the public at harm in the event of a catastrophic failure—all part of the responsibilities of a dam owner and being a good citizen of the region we serve.

It is easy to pass by tiny Lake Creek Dam and not notice it, as well as the other larger dams in our area along US-2 or Highway 200 that we have become used to being part of our landscape. We are fortunate to live in a region with an abundance of water and hydroelectric resources, which supply about 80% of the power in the Pacific Northwest.

In the United States, hydroelectricity makes up 12% of the power generated and is the largest source of renewable energy. Hydroelectric power is one of the cheapest sources of energy, which has helped keep rates low in the region.

If you are out and about this summer and have the opportunity to visit one of the many dams in our area, it is worth the few minutes to learn more about the valuable resource we have in our region.

Northern Lights Engineering & Operations Manager Kristin Mettke is an electrical engineer and has worked in the electric utility industry most of her career.