The federal judge overseeing efforts to make the Columbia Basin's federal hydroelectric dams safer for salmon is giving the Obama administration one last chance to come up with something better that won't violate the Endangered Species Act.

GRANTS PASS — The federal judge overseeing efforts to make the Columbia Basin's federal hydroelectric dams safer for salmon is giving the Obama administration one last chance to come up with something better that won't violate the Endangered Species Act.

U.S. District Judge James Redden in Portland on Wednesday gave NOAA Fisheries Service until Feb. 19 to decide whether to voluntarily take back their proposed improvements to the Bush administration plan, known as a biological opinion.

The judge said this can fix procedural problems with the Obama administration revisions that prevent him from considering them. But he added that there are deeper flaws, and urged the agency to produce a stronger plan based on the best available science, as the law requires.

"I will not sign an order of voluntary remand that effectively relieves Federal Defendants of their obligation to use the best available science and consider all important aspects of the problem," the judge wrote. "This court will not dictate the scope or substance of Federal Defendants' remand, but Federal Defendants must comply with the ESA in preparing any amended/supplemental biological opinion."

Redden warned NOAA fisheries that he will view with "heightened skepticism" any attempts to deal with the issues superficially.

In litigation stretching back 15 years, Redden has twice before found federal plans on how to balance cheap hydroelectric power against the survival of wild salmon violated the Endangered Species Act, forcing the government to devote more water to fish and less to power production.

Last September, NOAA chief Jane Lubchenco announced the Obama administration's revisions to the Bush plan, which it called the Adaptive Management Implementation Plan. It offered a tougher conservation plan for the fish that includes climate-change monitoring and the "last-resort" possibility of removing dams.

But until the revisions are formally rolled into the overall biological opinion, Redden said he cannot consider them.

NOAA Fisheries spokesman Brian Gorman said they would have to carefully consider the judge's letter and proposed order dictating the terms of revising the plan before deciding what to do.

Salmon advocates said the judge echoed what they have been arguing all along: that the plan needs to do more for salmon.

"They just tried to paper-over the problem," said Todd True, an Earthjustice attorney representing salmon advocates. "I think what the court said is, you've got to go back and look again and make a new decision. Maybe the Adaptive Management Implementation Plan will help you on some things. It's not enough standing alone."

The judge also urged NOAA Fisheries to work with other parties in the case, which include salmon advocates and the state of Oregon.