Fishery safe in swollen Madison

By Nick Gevock - 09/05/2008

The sudden rise in the Madison River this week due to headgates failing at Hebgen Dam will not harm fish, state biologists said.

In fact, the river's unseasonal high flow may help clean out gravel and kick up food to help improve habitat. And it hasn't made for shabby fishing either.

"It will tend to dislodge things like sculpins, nymphs and other small fish," said Mike Lum, an Ennis fishing guide. "The fishing has actually been pretty decent; we're not catching a lot of fish, but we're catching some big ones." When headgates at the dam broke Sunday, the river rose throughout the day from about 850 cubic feet per second to more than 3,500 cfs. The rise, while sudden, did not swell the river higher than normal spring runoff conditions.

Engineers with dam owner PPL Montana are working to stop the higher flows by plugging and then repairing the intakes at the headgate.

Mark Lambrecht, a PPL spokesman, said they plan to stop the higher flows Sunday, making the higher flow short lived.

The surge of water did not discolor the river. And the higher flow came at a time of year when the river is normally lower and perfectly clear.

The flow won't harm fish, said Mike Vaughn, a fishery biologist with the Montana Department of Fish, Wildlife and Parks. He said the higher flows will open up habitat for fish.

"It certainly changes their lives — they're living area has changed dramatically," he said. "It probably kicked up a bunch of aquatic insects and such." That likely allowed the fish to feed on more foods for a couple days. And the stronger flow should have flushed out some gravel areas, which improves spawning habitat.

Bruce Rich, southwest Montana fisheries manager, said while the flow wasn't planned, it won't be a problem for fish because it was nothing exceptional. He said as long as the flow is brought down quickly and doesn't persist, it should not affect brown trout that spawn in October.

In the meantime, anglers are enjoying some good fishing, although a different type than is usual for this time of year, Lum said. He said although the river is high, it's fairly clear compared to spring runoff.

Normally anglers are using grasshoppers on the surface this time of year. Now they're drifting streamer patterns meant to imitate smaller fish and stonefly nymph patterns that look like the bugs stirred off the bottom of the river by the higher flows.

"It just gives them more room to move around," Lum said of the higher flow. "It gives them more food at this time of year when they need it before winter." — Reporter Nick Gevock may be reached at nick.gevock@mtstandard.com