The agreement, which would open more than 300 miles of the Klamath, is not binding but nonetheless provides a formal framework to defuse deeply emotional arguments that have echoed through the region. For decades, warring interests have argued over who should benefit from the water flowing through the riverbanks and whether the need for electric power and agricultural irrigation should trump the needs of salmon.
In a conference call Thursday, Interior Secretary Dirk Kempthorne, a longtime opponent of dam removal in his native Idaho, hailed the provisional agreement as ending a bitter struggle among conservationists, Indian tribes and fishermen in the Klamath basin on one side and farmers and local communities on the other.
All the parties had coped with worst-case situations in the past decade. In 2001, irrigators had their water shut off, crippling agricultural production. In the dry year of 2002, the Interior Department ordered water distributed to irrigators and tens of thousands of salmon in the Klamath died; in 2007, low salmon populations in the Klamath led to sharply curtailed commercial fishing.
“After living through moments that would tax the character of most anyone, the good people of the basin came together,” Mr. Kempthorne said.
Gov. Theodore R. Kulongoski of Oregon, a Democrat, said the provisional agreement would be “a model not only for the West but the rest of the country of how the federal and state governments and private industry can work together.”
Thursday’s agreement follows the announcement nine months ago of a rapprochement between most of the warring groups, which joined in signing a roadmap for restoring the quality and vitality of the Klamath River by removing the dams. But PacifiCorp said it would not agree to their removal until the financial interests of the company’s customers were safeguarded.
The new agreement, which is expected to be final by June 2009, provides specifics on financing the dam removal. PacifiCorp, which is a subsidiary of the MidAmerican Energy Holding Company and operates as Pacific Power on the West Coast — would add a 2 percent annual surcharge, amounting to about $15 on average, for its 550,000 customers in Oregon and 45,000 in California.
In addition to the $200 million generated in part by these surcharges, $250 million would be raised by a bond issued by California. The dams would also be transferred to a new federal agency set up for the purpose, relieving PacifiCorp of liability during the actual removal.
The agreement also sets out a requirement for several years of scientific analysis of how removing the dams would affect water quality and fish habitat. The aim is to ensure that the environmental impact of the release of sediment would not be worse than leaving the dams in place. The oldest dam was installed more than a century ago.
The Interior Department would make a final decision on removing the dams in 2012.
The provisional nature of the agreement prompted supporters to curb their enthusiasm, but most said they believed the dams would be removed.
“We absolutely believe this will become final,” said Dean Brockbank, the vice president and general counsel of PacifiCorp. Mr. Brockbank added, however, that “we recognize there are hurdles to achieving a final agreement,” like the need for a new federal law allowing transfer of the dams to federal ownership.
In a reference to the impending change of leadership in Washington, Art Sasse, a spokesman for PacifiCorp, said: “It’s a flexible framework that recognizes that the administration is going to be passing the baton. But science — unbiased, unadulterated science — drives this process.”
Two major environmental groups, American Rivers and Trout Unlimited, offered immediate support for the proposal, as did representatives of the farm communities and the Indian tribes based along the river.
Greg Addington, the executive director of the Klamath Water Users Association, which serves more than 1,200 farm and ranching families, said that even though his constituency “believes we should be building more dams, not taking them out,” his members “have been pretty practical over the years in looking at this as an alternative that might happen.”
Steve Rothert, a spokesman for American Rivers, an environmental group, said Thursday: “This is a bell that PacifiCorp will not be able to unring. They are clearly stating their intent to remove these dams because this is a good business deal for them.”
For the company, the alternative to removing the dams would be renewing its long-term license, which would have required it to spend hundreds of millions of dollars on new systems and structures to mitigate the impact on salmon.