Governor Kulongoski has signed a bill related to tearing down four hydropower dams operated by Pacific Power on the Klamath River. It's been hailed as a milestone, but it could also turn out to be another step in a big mistake.

Senate Bill 76 authorizes Pacific Power to start collecting, in 2010, surcharges to help pay for removal of each of the four dams, which the bill anticipates will be done in 2020.

The bill is an outgrowth of tentative agreements between Oregon, California, PacifiCorp and several interest groups in the Klamath River Basin, including Indian tribes and the fishing industry. The goal was to end the "water wars" there, restore salmon runs and provide adequate water for the region's farm economy and lakes.

Among other things, the deal calls for the dams to be razed. After fighting the idea for years, Pacific agreed on the grounds that the cost of relicensing the dams under new conditions, such as adding fish ladders, would be much greater than taking them out. Since consumers would pay the costs either way, the lower-cost alternative of dam demolition was the prudent choice.

Environmental groups and the tribes of the region have done all kinds of analyses, all concluding that removing the four dams on the lower Klamath would restore the free-running river and, by opening up hundreds of miles of upstream fish-rearing habitat, restore the salmon runs that have shown sharp declines since about the 1990s.

But here's the thing: Copco 1, a dam on the Oregon-California border, was completed in 1918. Just below it, Copco 2 was finished in 1925. If these dams had caused fish runs to collapse, the runs would have been gone for nearly a century now.

The last of the dams, Iron Gate, south of the state line and east of I-5, was finished in 1962. Since then it has blocked fish from migrating upstream. But for most of those 40-plus years, there was no emergency with fish runs on the Klamath. Evidently the salmon did OK in the streams open to them below Iron Gate.

Isn't it likely, then, that conditions other than the dams are mainly responsible for the fish shortage in the Klamath and off the Oregon and California coast?

Under the agreements signed last fall, the secretary of interior has until 2012 to decide whether the dams actually should come out. Eventually Congress also would have to give its consent.

Also, apart from the fate of the dams themselves, a final agreement has yet to be reached on a long-term plan for allocating the water in the Klamath basin.

Assuming all that is accomplished and the dams are taken out but the fish runs don't return and there still isn't enough water for all the would-be users?

Then the only tangible result will be that the a significant source of hydropower - less polluting and more renewable than burning fossil fuels - will have been lost. (hh)