"These rivers are in critical condition," said Larry Peterman, FWP Fisheries Administrator. "We are closing the Jefferson River and the upper Big Hole River to angling to reduce the stress on the wild and native trout populations in these popular fisheries."
Under the Jefferson River Drought Management Plan, the low-flow trigger to close the river to angling is 250 cubic feet per second. On Friday, at Twin Bridges, the Jefferson River's flow dropped to 245 cfs.
The Big Hole Drought Management Plan separates the Big Hole River into three "drought emergency" reaches. Today's closure encompasses the middle reach from the mouth of the North Fork to Dickie Bridge, just upstream from the community of Wise River. This reach is critical summer grayling habitat. The upper reach of the Big Hole River, a 19-mile stretch from Rock Creek Road to the mouth of the North Fork, has been closed to angling since June 27.
The stream flow near the Mudd Creek Gage on the middle reach of the upper Big Hole River has fallen to 53 cubic feet per second. The Big Hole's drought plan recommends closure when flows drop to 60 cfs.
The 74-mile lower reach of the Big Hole River is running at about 153 cfs. Its closure trigger is 150 cfs. "Anglers should be aware of low-flow conditions and are urged to limit their fishing to the morning hours when water temperatures are generally cool," Peterman said.
FWP closed the streams under a new drought emergency decision process approved by the FWP Commission that delegates angling-closure authority to FWP Director Jeff Hagener and the FWP Commissioner representing the area where the body of water is located. The area's FWP Commissoner is Tim Mulligan of Whitehall.
The closures are aimed at protecting the Jefferson River's wild rainbow and brown trout populations and the Big Hole River's genetically pure native Arctic grayling and the river's wild rainbow and brown trout.
Both of these rivers have the benefit of local organizations working cooperatively to keep water in these rivers through water conservation, reducing irrigation and other voluntary measures.
The Big Hole Watershed Committee, a group of volunteers representing agriculture, municipalities, business, conservationists, anglers and federal, state and local agencies developed the Big Hole Drought Management Plan.
The Jefferson River Watershed Council set 250 cfs as the trigger point to close the Jefferson in a drought management plan developed last year.
In each watershed, in addition to the fishing closure, local irrigators are voluntarily contributing water and their watershed councils are attempting to maintain the in-stream flows for the benefit of these important wild and native trout streams.
FWP will consider reopening the Jefferson River to angling when flows reach 300 cfs for seven consecutive days. The middle reach of the upper Big Hole would reopen when flows reach 80 cfs for seven consecutive days.