The earliest recorded activity proposing the development of an irrigation project in the Big Bend area of the Columbia River began in 1903. For many years proponents of such an undertaking promoted the construction of a large irrigation project. Actual construction began in 1933 with the start of Grand Coulee Dam. Construction has continued during the ensuing half-century. Planning and construction of the project was carried out by the United States Bureau of Reclamation. The project is planned to ultimately irrigate 1,095,000 acres and presently provides water to 671,000 acres.
The East Columbia Basin Irrigation District, Quincy Columbia Basin Irrigation District, and South Columbia Basin Irrigation District were formed in 1939 and acted as spokespersons for respective landowners in dealing with the Bureau of Reclamation. On December 18, 1968, the Bureau of Reclamation transferred the operations and maintenance responsibilities for certain project irrigation and drainage systems to the Districts. The transfer documents are commonly referred to as the "1968 Amendatory Repayment Contracts".
Provisions of referenced contracts allowed the irrigation districts to develop power projects. On May 10, 1980, the Board of Directors of the three Districts entered into an agreement for the development, operation, and maintenance of hydroelectric generating facilities to be developed on the irrigation systems of, or related to, the Columbia Basin Project. The main points of the 1980 agreement covered development, operation, and maintenance of hydroelectric developments, division of power revenues, creation of the Grand Coulee Project Hydroelectric Authority and designation of the South District as lead agency for the initial developments until such time as the Authority was created and operational.
The agreement creating the Grand Coulee Project Hydroelectric Authority was made and entered into the 14th day of December 1982, and lead agency power development responsibilities were transferred to the Authority in March 1988. The Authority performed the power development responsibilities as the agent and the representative of the Districts.
On March 26, 2015, the Board of Directors of the Grand Coulee Project Hydroelectric Authority approved changing the Authority's name to Columbia Basin Hydropower. During the Irrigation Districts April Board Meetings, each District approved the name change. Resolution 2015-07 dated June 23, 2015 confirmed the name change to Columbia Basin Hydropower (CB Hydropower) effective July 1, 2015. CB Hydropower has established its business headquarters in Ephrata, Washington.
CB Hydropower performs operation, maintenance, and administrative functions for five hydropower projects owned by the Districts - Main Canal Headworks, Summer Falls, Russell D. Smith, Eltopia Branch Canal (E.B.C.) 4.6, and Potholes East Canal (P.E.C.) 66.0. The generation from the five power developments operated and maintained by CB Hydropower is purchased by the City of Seattle, the City of Tacoma, and Avista Corporation. The general power plant data and start dates can be found on the Licensed Projects tab.
CB Hydropower provides Federal Energy Regulatory Commission (FERC) liaison support and administrative functions for two additional plants owned by the Districts - Quincy Chute and Potholes East Canal (P.E.C.) Headworks. Grant County Public Utility District operates and maintains the projects under forty-year purchase agreement from the date of commercial operation. The general power plant data and start dates can also be found on the Licensed Projects tab.