The Bureau of Reclamation reduced outflows from Big Horn Lake Tuesday from 1,900 cubic feet per second down to 1,500 cfs, in a move to increase the water level of the reservoir.


The BuRec estimates that the reduced inflows will stand until the reservoir has adequate storage for the next year. Currently, Big Horn Lake sits at 3,607 feet, about 32 feet from full pool.


BuRec Montana area director Dan Jewell said in a conference call Tuesday with stakeholders from Montana and Wyoming that they are being conservative with outflows so that there will be enough storage in the reservoir to have adequate lake levels throughout the summer. Jewell indicated Tuesday that the reduced flows could last about 25 days, but that depends on inflows.


Jewell said that the reduced releases stem from an April 21 meeting when the BuRec proposed cutting back outflows from 1,900 to 1,650 cfs because inflows to the reservoir weren’t as much as they expected. In talking with stakeholders at the April meeting, an agreement was reached to delay reducing the outflows in hopes that more water would come into the reservoir through snowmelt runoff and tributaries.


The group agreed that if conditions didn’t turn around, then a change would be made to make up for lost storage and drop outflows below 1,650 cfs.


After Tuesday’s conference call, the BuRec decided to drop outflows to 1,500 cfs.


“If we don’t have sufficient storage, we’re not going to adequately meet any of the multipurpose demands on the system,” Jewell said. “I think we’ve learned over years that we need a relatively full pool going into the fall.”


Jewell said the BuRec manages for several different reasons, including reservoir and downstream recreation needs, contract obligations for irrigation and hydroelectric power, to name a few.


“I would point to 2006, the year we were not able to achieve levels we hoped to, which precipitated a lot of the controversy we’re experiencing today,” Jewell said, “and we’re not anxious to repeat that situation.”


Big Horn Canyon NRA acting assistant superintendent John Keck told the Chronicle that the water level issue affects the interests of the Park Service throughout NPS land near Big Horn Lake, not just at Horseshoe Bend. He said the Park Service is mandated through congress to provide recreation opportunities, including boating, fishing, camping and other activities, and a low lake level impacts all of those areas. He said facilities built around the lake such as campgrounds, concessions and boat launches were built to take advantage of a full lake.


“Our intent is to support the Bighorn Canyon National Recreation Area,” Keck said. “We’re trying to focus on getting people out there.”


Local media reports indicate that the reduction in flows will negatively impact Montana fisheries.


Friends of Bighorn Lake President Bob Croft said, “The bureau wants to get the lake full so there’s enough water for everybody [in the future], not just to fill an immediate need like the fisheries.”


Jewell said that the above-average snowmelt runoff forecast in the Big Horn Basin would likely provide enough water to make everyone happy as the spring season progresses.


“I’m pretty confident we’ve got quite a bit of water in the mountains, it’s just a matter of when it’s going to show up,” he said.


Lake levels need to be at 3,618 feet to launch boats at Horseshoe Bend, 11 feet above where the lake is now.