The Environmental Protection Agency will not appeal a January court ruling that found the agency overstepped its authority in trying to regulate water flow in Accotink Creek in Virginia, the state announced Monday.

Virginia Attorney General Ken Cuccinelli said the EPA will accept the ruling of Judge Liam O'Grady, who said the federal agency violated the Clean Water Act and couldn't order Fairfax County officials to spend money to cut the flow of the creek to protect the habitat of worms, snails and insects.

The ruling will save state taxpayers an estimated $300 million in costs, said Cuccinelli, who joined Fairfax County and Virginia Department of Transportation officials in filing the lawsuit last year.

"This EPA mandate would have been expensive, cumbersome, and incredibly difficult to implement," Cuccinelli said. "And it was likely to do more harm than good, as its effectiveness was unproven and it would have diverted hundreds of millions of dollars Fairfax County was already targeting for more effective methods of sediment control."