After years of negotiation, the United States and Canada have reached a tentative agreement renewing the Columbia River Treaty.

It appears that the tentative agreement is favorable to the United States and regional interests. The proof, however, will be in a final treaty ratified by the U.S. Senate.

The river system is important to the economy of the Pacific Northwest. The Columbia River and its tributaries account for 40% of U.S. hydropower, irrigate $8 billion in crops and move 42 million tons of commercial cargo valued at $28 billion.

The original treaty, signed in 1961, was negotiated in the wake of catastrophic floods that destroyed the second-largest city in Oregon. Floodwaters wiped out Vanport in 1948, killing 15 people and displacing 18,000.

The treaty had one main goal: preventing future flood disasters. That was done by building four treaty dams — the Arrow, Duncan and Mica dams in Canada and the Libby Dam in Montana.

Under the treaty, Canada prevents flooding of the Columbia by draining the reservoirs behind those dams to make room for snowmelt in the spring. To compensate Canada for the lost revenue from electricity generation, Canada receives payments from U.S. utilities and is entitled to a portion of the power generated by U.S. dams.

According to the updated agreement, the United States will receive more of the electricity generated from the river system. Adequate flows should be available for irrigation and river transportation.

Agricultural interests are “cautiously optimistic.”

Although the administration touted the deal’s provisions for conservation stewardship and its protections for salmon, environmental groups aren’t happy with the tentative deal.

Northwest environmental groups expressed “frustration and disappointment” with the agreement in principle, saying it does not adequately address the crisis facing the Columbia River ecosystem and dwindling salmon and steelhead runs.

At this stage, the deal is tentative and can still be altered in the weeks leading to its ratification.

The devil, they say, is in the details. We hope the elements existing in the tentative agreement that warrant cautious optimism are carried through to the final deal.