Plans for big Grand Coulee hydro project detailed

Chamber of commerce members Thursday heard details on a proposed project that could put huge conduits for water under the community to produce more power and create jobs.

The proposed Banks Lake hydroelectric pumped storage project could be operational by the year 2025.

Tim Culbertson, and a team from Columbia Basin Hydropower, outlined a project that could require some 2,600 workers during construction and as many as 100 permanent employees.

Culbertson spoke at the Grand Coulee Dam Area Chamber of Commerce’s weekly luncheon at The Siam Palace.

He said licensing could take as long as three years, with seven years or more construction time.

The project would take water from Banks Lake through a large penstock (pipe) to a pump-generator station near Crescent Bay on Lake Roosevelt, generate electricity and then pump the water back into Banks Lake later. That process would actually result in a net loss of energy, but would be flexible enough to supplement the burgeoning renewable energy sector (wind and solar power) that has no way to store energy.

Culbertson said that a large 35-foot, or two 20-foot, pipes would go underground and take water from the bottom of Banks Lake about 400 feet south of North Dam.

The Banks Lake project would provide up to 500 megawatts of energy and capacity to offset the retirement of some coal-fired energy plants in the Northwest.

Culbertson said while the project could provide 35 hours of continuous generation, it is unlikely that the duration of continuous operation would last that long. He said that the level of Banks Lake would drop no more that one or two feet during long operating periods.

Columbia Basin Hydropower is owned by three irrigation districts in the Columbia Basin — East Columbia Basin, Quincy Columbia Basin and South Columbia Basin.

Culbertson said operation of the pumping plant could be run by permanent employees or through a contract arrangement with the Bureau of Reclamation’s John W. Keys III Pump-Generating plant.

Columbia Basin Hydropower currently has seven power producing units under operation, with the power going to the cities of Tacoma and Seattle.

He said the firm’s talks with Reclamation are going better than they once were.

The underground pipe would be from 6,000 feet to 9,000 feet long, depending on where engineers decide to locate the overall system. The underlying granite rock formations are ideal for drilling, and Culbertson didn’t think that would pose a problem.