Allowing the Columbia to flow more like a natural river would benefit the region financially, bringing hundreds of millions of dollars in benefits to local communities, Northwest tribes say.

In a 150-page study, the tribes make a financial case for modernizing dam operations in the Columbia Basin and releasing more water during dry years to aid struggling salmon runs. Even modest changes could add up to $19 billion annually in economic benefits for the region, the study said.

“The river isn’t just a machine to produce power, or a (holding pond) to protect Portland from flooding. It’s there for all of us,” said D.R. Michel, executive director of the Upper Columbia United Tribes.

Michel said the tribes are often told restoration work would have costly tradeoffs in lost power production, irrigation or flood control. The study brings rigorous analysis to demonstrating the financial benefits of restoration work, he said.

The release of the analysis comes as the U.S. and Canada prepare to renegotiate the 1964 Columbia River Treaty, which governs hydropower and flood control operations along the 1,243-mile river. Columbia Basin tribes are pushing for more emphasis on ecosystem functions in an updated version of the treaty.

Tacoma-based Earth Economics was hired by the tribes to do the study. The company is a national leader in economic analysis demonstrating the value of intact ecosystems and restoration work, said David Batker, Earth Economics president.

Earth Economics’ earlier study of the shrinking Mississippi River delta put a value on the potential cost of about 2 million residents being displaced from their homes. The study helped build bipartisan support for restoration work aimed at preserving the delta, Batker said.

“These natural attributes have value,” he said. “We need to appraise these assets just like we appraise other assets.”

The 258,000-square-mile Columbia River basin provides about $198 billion annually of value in areas such as water, food, recreation and flood risk reduction, the study said.

Increasing spring and summer flows to aid salmon migration during dry years would cost about $69 million per year in reduced power production, which has an overall value of about $3 billion annually in the basin, the study said.

However, the study’s authors calculated a net benefit of $1.5 billion annually in the basin from the water releases. The gains came in areas such as commercial fishing, tribal fishing and recreation.

“There is a substantial value. There is a benefit to all of the citizens in the basin,” said Jim Heffernan, policy analyst for the Columbia River Inter-Tribal Fish Commission.