Parties The treaty is between the governments of Canada and the U.S., but three agencies are charged with carrying out treaty provisions. They are BC Hydro, a utility owned by the Province of British Columbia, and for the U.S. both the Bonneville Power Administration (BPA) and regional Army Corps of Engineers. These are called the “Canadian Entity” and the “U.S. Entity.”

Dams built Canada had to build two Columbia River dams, Mica and Arrow (renamed Keenleyside), and Duncan Dam on the Duncan River.

It also required the U.S. to build Libby Dam on the Kootenai River in Montana. Libby’s reservoir extends into British Columbia. Duncan is the only one that doesn’t have a powerhouse.

Water storage Canada provides 8.45 million acre feet of water storage in its treaty reservoirs for flood control through 2024.

Storage payment The U.S. paid Canada one lump sum of $64.4 million for water storage when treaty dams were complete. This was half the estimated cost of total flood damages prevented by the extra storage between 1968 and 2024.

Shared power benefits The U.S. must deliver electricity to Canada equal to half the estimated U.S. power benefit derived from the Canadian water storage. This is called the “Canadian Entitlement.”

It totals about 500 average megawatts and is valued yearly at $220 million to $350 million, depending on power prices.

NCW’s PUDs provide 27.5 percent of this power. In 2010, the PUDs’ contribution to Canada totaled about 138 average megawatts of power — enough to supply about 69,000 Northwest homes. This power must be supplied during times of peak demand, when electricity is most expensive.

Cross-border flow The treaty generally prevents either the U.S. or Canada from diverting water that would alter the Columbia’s cross-border flow.

Post 2024 flood-control Existing flood-control provisions expire in 2024, even if the treaty continues, unaltered. Post 2024, Canada will no longer be required to reserve 8.45 million acre feet of storage for downstream flood control.

Instead, the U.S. would have to operate its own Columbia River and tributary reservoirs for maximum water storage, or build more storage. At times when this capacity isn’t expected to be enough, the U.S. could, for a price, call upon Canada for additional storage. Alternatives to this could be negotiated, but no suggestions have yet been made.

If the treaty ends in 2024

Canadian Entitlement ends Canadian Entitlement power deliveries would end. All U.S. dams on the Columbia could use or market this power and pocket the $240 million to $350 million.

Post 2024 flood control measures would begin. (See above)

More Canadian water diversions Canada would have an option to start or increase diversions of Kootenai River into the Columbia. This would reduce generation at Montana’s Libby Dam. Experts say this isn’t likely to happen due to high costs and adverse environmental impacts.

Source: Bonneville Power Administration; Army Corps of Engineers; Chelan, Douglas, Grant County PUDs