The purchase is the latest move in a decade-old dispute between farmers, fishermen, conservationists and government agencies over the area's water supply. The local lake and river are inhabited by endangered and threatened fish, which get high priority for water supplies. The Reclamation Bureau calculated earlier this year that once water was provided for the endangered fish, there was none left for 90 percent of the farmland served by the Klamath Project, a federal irrigation system along the Oregon-California border.

That prompted complaints from farmers, so in July, 75,000 acre-feet of water was released to the parched farmers. Government officials said there was only enough water to help farmers and allocated none to the refuge, which normally gets the water left over after farms are irrigated.

That prompted an outcry from conservationist groups, which filed a suit claiming it was a violation of the Endangered Species Act. In light of the water purchase plan, the conservationists decided to hold off on seeking a court order to provide water to the refuge. A federal judge is overseeing a mediation process to settle the conflict over water supplies, which has intensified this year due to the severe drought in the area.