BOISE - A federal judge has ruled in favor of an environmental group seeking to reverse the Bureau of Land Management's decision to renew grazing permits in central Idaho's Pahsimeroi River Watershed.

U.S. District Judge Edward Lodge's decision Wednesday agreed with Hailey-based Western Watersheds Project that the federal agency had violated the National Environmental Policy Act by failing to fully analyze potential consequences.

"When, as here, BLM disregards the law, it disregards the public interest and undermines its own credibility," Lodge wrote.

The federal agency had renewed four 10-year grazing permits for a total of 48,000 acres in the watershed.

Lodge ruled that the BLM failed to allow required public participation in the process; didn't adequately consider bull trout even after the agency became aware it erred in stating bull trout didn't exist in the allotments and failed in an analysis of the effects of the grazing.

He called the agency's decision for the allotments arbitrary and capricious.

The National Environmental Policy Act "requires BLM decision makers to take a 'hard look' at the environmental impacts of their decisions; it does not allow BLM to rubber stamp applications in order to maintain the status quo," the judge said in his ruling.

He noted that the agency considered three alternatives in its environmental assessment, but all three included comparable levels of grazing, with no alternative that considered no or limited grazing.

Lodge gave the federal agency one year to revise its analysis, consider public comments, and reissue decisions. He said the year would also give those granted the grazing permits time to plan for the future.

"The decision makes clear that BLM managers have chosen to ignore livestock grazing impacts to the environment," said Katie Fite, biodiversity director for Western Watersheds Project. "The court's decision will further the protection of bull trout and sage grouse in the breathtakingly beautiful public lands of the Pahsimeroi Valley."

Cheryle Zwang, deputy state director for the office of communication for Idaho BLM, said the agency was reviewing the decision and declined to comment.