Baseload, Hydropower, Storage

Federal Regulators Seek Input on Permit for 500-MW Owyhee Pumped Storage Project

The Federal Energy Regulatory Commission issued a July 1 notice about a revised application filed on June 30 by Owyhee Hydro LLC for a preliminary permit, under which the company would study the feasibility of the 500-MW Owyhee Pumped Storage Project.

The project would be located on Lake Owyhee near Adrian in Malheur County, Oregon. The sole purpose of a preliminary permit, if issued, is to grant the permit holder priority to file a license application during the three-year permit term.

The proposed project would consist of:

  • a new 1,200-foot-long zoned earth and rockfill or concrete-face rockfill dam forming a lined upper reservoir with a surface area of 109 acres and a storage capacity of 4,035 acre-feet at a maximum surface elevation of 4,320 feet mean sea level (msl);
  • an existing 833 foot-long concrete arch dam forming the existing Lake Owyhee (lower reservoir) with a surface area of 13,900 acres and a storage capacity of 1,120,000 acre-feet at a maximum surface elevation of 2,650 msl;
  • a new 14,100 foot-long conduit connecting the upper and lower reservoirs consisting of a 2,200 foot-long, 17.1 foot-diameter concrete lined lowpressure tunnel, a 7,100 foot-long, 17.1 foot-diameter concrete and steel-lined pressure shaft, and a 4,800-foot-long, 20.5 foot-diameter concrete-lined tailrace;
  • a new 80 feet long by 280 feet wide by 120 feet high powerhouse containing four reversible pumpturbine units rated at 125 MW each for a total capacity of 500 MW; and
  • either 2.6 miles or 8 miles of 500-kV transmission line interconnecting with the Boardman-Hemingway Line, depending on design of infrastructure.

The estimated annual generation of the Owyhee Project would be 1,533,000 megawatt-hours.

The deadline for filing comments, motions to intervene, competing applications (without notices of intent), or notices of intent to file competing applications is 60 days from the issuance of this July 1 notice.

Lead image credit: Oregon Department of Fish & Wildlife | Flickr

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