1964 was a critical year in the development and operation of the Columbia River power system. It was the year Congress ratified the Columbia River Treaty (September 16), approved the Pacific Northwest Consumer Power Preference Act (August 31), and appropriated money for initial construction of the Pacific Northwest/Pacific Southwest Intertie (legislation approved June 24). It also was the year 16 entities in the Northwest, including federal water and power agencies and electric utilities, signed the Pacific Northwest Coordination Agreement, on Sept. 15 (here is a link to a report on the agreement written for the Power Council in 1989). The agreement commits the participants to coordinate operations of their power plants to maximize their efficiency.
The PNCA was revised in 1997, in part to recognize dam operations that protect migrating fish in the spring and summer and reduce hydropower generation as a result. The agreement currently is in effect through September 15, 2024.
Through the PNCA, major hydroelectric generating plants and electric systems that serve the Pacific Northwest, including dams on the Columbia River in the United States, are operated as if they are controlled by a single entity. This is important because the power generation benefits of the Columbia River Treaty are based on an assumption that the operation of the Columbia River dams will be coordinated between the United States and Canada. The PNCA, which was signed just before the treaty was ratified, assures that coordination among dam operators in the United States.
A key benefit of the agreement is to make low-cost surplus, or “secondary,” power available to the participating members:
“The Parties shall coordinate their Systems to make available to each Party its optimum Firm Load Carrying Capability (“FLCC”), to provide optimum FLCC for the Coordinated System, and, consistent with these objectives, to produce the optimum amount of useable secondary energy for each Party.”
FLCC is the amount of energy the region’s generating system, or an individual utility or project, can be called upon to produce on a firm – constant, 24 hours a day -- basis during actual operations. FLCC is made up of hydropower and non-hydropower resources, including power purchases. For the hydropower system, the amount of FLCC depends on the amount of reservoir storage – “fuel” for the dams -- currently available. It’s an important concept because maximizing FLCC also maximizes the amount of secondary – surplus – energy available to the PNCA participants, low-cost power that can help participants reduce the cost of meeting their customers’ demand. Put another way, when the power system is coordinated, participants can meet their load requirements with a combination of their own generation and low-cost, surplus energy, reducing their overall costs. Thus, having the “optimum amount,” in the words of the agreement, of secondary energy available is a good thing for utilities.
The PNCA incorporates legal requirements for power system operations, notably the NOAA Fisheries and U.S. Fish and Wildlife Service’s biological opinions on operations of the Federal Columbia River Power System to protect 13 species of salmon and steelhead that are listed for protection under the Endangered Species Act and that migrate in the Columbia and Snake rivers.
The biological opinions require additional flows and spills at dams between mid-April and late August to aid fish migration. These requirements caused changes in dam operations, such as increasing winter storage in order to provide the increased volumes in the spring and summer (before the biological opinions, reservoirs were drafted deeper to meet firm energy loads in the fall and winter), and also power generation by spilling water away from turbines to improve juvenile fish passage survival. The spill requirements reduce the output of the Columbia and Snake river hydropower system by about 1,100 average megawatts. Expressed as energy, that is roughly the average power demand of the city of Seattle in 2016.
Coordination among hydropower operators on the same river or rivers recognizes that dams are interdependent and provides the opportunity to maximize the efficiency of operations while also providing energy to meet the regular power demand of the operating utilities’ customers. Coordination of operations also provides an opportunity to coordinate long-term planning for future dam operations and resource additions where they are needed as demand grows. Historian Jim Kershner provides an excellent history of coordination among power producers in the Northwest and Canada in his HistoryLink essay on the Northwest Power Pool. Engineers with the Power Pool members, which included utilities in British Columbia and Alberta in addition to the Northwestern United States, provided invaluable assistance to American and Canadian negotiators as they crafted a plan for cooperatively managing the Columbia and its dams in the Columbia River Treaty.
Today the PNCA includes 17 participants: Bonneville; the Corps of Engineers; the Bureau of Reclamation; the cities of Eugene, Oregon, and Seattle, and Tacoma, Washington; the Grant, Chelan, Pend Oreille, Douglas, and Cowlitz county public utility districts, all in Washington; Puget Sound Energy; Portland General Electric; PacifiCorp; Avista Utilities (originally Washington Water Power), the Montana Power Company (today Northwestern Energy and PP&L Montana); and the Colockum Transmission Company, a subsidiary of Alcoa Aluminum’s Wenatchee Works, which purchased 23 percent of the output of Rocky Reach Dam from the Chelan PUD before Alcoa idled the smelter in 2015 in response to steep declines in the worldwide price of aluminum.