The analysis by the Northwest Power Council estimates the increased cost could range from $125 million to $560 million in 2006.
U.S. District Judge James Redden in October ordered the Bush administration to rewrite its plan for ensuring that threatened and endangered salmon are not harmed by the federal hydroelectric dam system on the Columbia and Snake rivers.
The ruling came after the National Wildlife Federation sued the federal government, arguing that dam operators need to spill more water over dams in the Columbia Basin next year to help young fish migrate to the ocean.
But the Northwest Power Council analysis suggests those proposed changes in dam operations would reduce the reliability of the regional power supply and boost the cost of generating electricity.
