WASHINGTON — An $800 million water-sharing deal for the Klamath Basin, years in the making, is too expensive for today’s cost-conscious Congress to endorse, Sen. Ron Wyden, D-Ore., said Thursday.

“After considerable thought, I have concluded that the Klamath Basin Restoration Agreement is simply unaffordable in the current federal budget environment,” Wyden said. “Working in good faith, there’s got to be a way to accomplish the agreement’s objectives at a more affordable price tag.”

The Klamath Basin is 16,000 square miles that drain into the Klamath River as it wends more than 250 miles from its headwaters in Southern Oregon through Northern California to the Pacific Ocean. The demands on the basin’s water outstrip supply. In March, after 38 years of litigation, the Oregon Water Resources Department adjudicated the competing claims to the water.

Essentially, under the principle of first in time, first in right, the Klamath Tribes were awarded top claim on much of Upper Klamath Lake and portions of its tributaries.

With dry conditions in Oregon fueling fears of a drought and water shortages, the Klamath Tribes and other high-priority rights holders exercised a “call” on their water claim earlier this month. Some with lesser claims — largely ranchers and irrigators in Oregon — are afraid they won’t have enough water for their livestock and crops.

Wyden convened Thursday’s hearing before the Senate Energy and Natural Resources Committee, which he chairs, to ask for suggestions from a variety of stakeholders.

With 16 witnesses, including state, county and federal officials, as well as representatives of tribal groups, power companies, and agricultural and environmental interests, the hearing had the informal feel of a town hall meeting. Wyden let each witness speak, then opened the floor to discussion of what might come next.

“We have to stop lurching from this set of complete winners and complete losers,” said Richard Whitman, policy director for Gov. John Kitzhaber’s Natural Resources Office.

In 2001, the last time a drought triggered major calls on water rights, the Klamath Project, a federal water management program, did not deliver water to all of farmers and ranchers in its coverage area. The following year, 30,000 adult salmon died in the lower Klamath River. In 2006, severe limitations were imposed on ocean fisheries off the Oregon and California coasts because of decimated stocks in the Klamath Basin.

“A long-term, durable solution that is driven by at the local level by those who are most directly affected is the best and perhaps only opportunity to avoid the year-to-year crises that plague this basin,” said Michael Connor, a commissioner with the Bureau of Reclamation.

After years of negotiation, most of the local stakeholders agreed to the Klamath Basin Restoration Agreement, or KBRA, which seeks to maximize the water available to everybody by sharing the shortages across different water users.

The agreement had to be endorsed and funded by Congress, so it is up to Congress to act, said Donald Gentry, chairman of the Klamath Tribes of Oregon, which have 3,700 members. Since 2001, taxpayers have spent an average of $18 million a year in disaster relief, he said.

“The question before Congress is not whether to spend money, but whether to spend it on an endless series of Band-Aids or to spend it on a permanent remedy,” he said.

During the last Congress, legislation was introduced by Sen. Jeff Merkley, D-Ore., that formalized the agreement and set funding levels, but the bill never made it out of committee. No new legislation regarding the Klamath Basin agreement has been introduced during this session.

Initially, projections put the cost of the KBRA, which includes significant restoration and preservation efforts, at $1 billion, but the parties trimmed that to $800 million, said Connor.

California plans on contributing $250 million to the KBRA, but that is dependent on the passage of a larger funding bond in 2014, said John Laird, California’s Secretary for Natural Resources.

Even counting that contribution, $550 million is too much to expect from Congress, Wyden reiterated. Cutting expenses by 25 or 30 percent would make it much more palatable, he said.

“The political consensus and the cost go hand in hand,” Wyden said. If the stakeholders can reduce the costs, then Congress will recognize that they are working hard to bring forward something viable, he said.