EUREKA -- In what's being called a major victory for North Coast tribes and fish advocates, the U.S. 9th Circuit Court of Appeals Tuesday stood by a 2000 plan to restore water to the Trinity River that's being diverted to the Sacramento Valley.

The 9th Circuit overturned a lower court decision earlier this year that had ordered more environmental studies be done before the 2000 restoration plan is implemented. The appeals court ruled the existing studies in the plan were adequate.

"Nothing remains to prevent the full implementation of the (2000 Record of Decision), including its complete flow plan for the Trinity River," the court ruled.

Tuesday's ruling is the latest in a battle over the Trinity River that has raged ever since water began being diverted to the Sacramento Valley in the 1960s. The ruling upholds a plan to restore the Trinity River ordered in 2000 by then-Secretary of the Interior Bruce Babbitt.

North Coast tribes, local government leaders and fish advocates, who all see the restoration plan as key to repair the region's fisheries, have worked together to fight a lawsuit the Westlands Water District, San Luis and Delta-Mendota Water Authority in the Central Valley have waged to stop the implementation of the restoration plan.

"I got the phone call when I was in a meeting and I couldn't keep the smile off my face," said Hoopa Valley Tribe Chairman Clifford Lyle Marshall. "It is a great day."

Others who helped in the legal battle include Humboldt and Trinity county officials, fishermen's groups like CalTrout and the Yurok Tribe.

"This is a gigantic leap forward," said Humboldt County Supervisor Jimmy Smith, a former commercial fisherman. "We were up against some of the most powerful forces in the Central Valley and it looks like perseverance has finally paid off."

Smith and other leaders anticipate the Trinity's restoration will go a long way in rebuilding the fisheries in the Trinity and Klamath rivers.

North Coast Congressman Mike Thompson also hailed the decision.

"This is a great victory for the Hoopa Tribe and Northern California's coastal communities, whose economy and jobs have been decimated by declining fisheries," Thompson said, in a press release from Washington, D.C.

Since the completion of the Lewiston and Trinity Dams on the Trinity River in 1963, up to 90 percent of the Trinity River water has been diverted to the Central Valley. The result has been the near destruction of the river's fishery. Salmon and steelhead populations are found in less than 10 percent of their historical range and most are either listed, proposed for listing or under status review for listing under the Endangered Species Act.

The word from the Central Valley Tuesday was that officials there are evaluating the appeals court's decision.

"We're looking at it very carefully and evaluating all our options," said Tupper Hull, spokesman for the Westlands Water District. Hull characterized the court's decision as "mixed," meaning the court did uphold the lower court's decisions that at least two biological studies relied on in the 2000 plan were inadequate.

Hull added that the district continues to be hopeful that a settlement can be reached. While he could not be specific on exactly how a loss in Trinity River water would impact Central Valley users, Hull did say the issue is complex and he hopes parties on all sides understand that Central Valley users will be affected.

"Central Valley projects and facilities are enormously complex and interrelated systems," Hull said. "We recognize there is a need to address fisheries on the Trinity River. The problem is ... that we have to address those issues from a much broader, statewide perspective."

Under the 2000 plan upheld by the federal appeals court Tuesday, the volume of water flowing to the Trinity will vary each year, depending on whether its a dry, normal or wet year.