Some fish survived the silt spill last month at Willwood Dam.
With a full pool upstream of the dam, the Shoshone River was rendered its typical cloudy emerald hue as Wyoming Game and Fish Department sought to calculate the fish population on Wednesday.
The crews were electro-fishing a couple miles downstream of the dam, delivering a light electrical jolt in the water to temporarily stun the fish and ease their capture with a net.
Jason Burckhardt, Game and Fish fisheries biologist, said they were collecting brown, rainbow and cutthroat trout along with mountain whitefish and a few suckers.
“We’re finding a few fish,” he said.
It was just past noon, but cold on the river, especially in the shade. In their waders, coats, wool caps and rubber gloves, the guys resembled unwavering winter anglers. Where they were working, the river was serene as a summer morning, but downstream, rapids surge like bunches of water jets in a linear hot tub.
A trout could be seen thrashing within the webbing of a net; its flashing skin gleaming like a sprinkle of green glitter caught in the breeze.
“I’m glad there are some fish down here,” Burckhardt said.
Burckhardt said he could only guess at the total fish population, but could provide a more accurate count in a couple weeks.
It was a catch-and-release operation. Game and Fish capture, measure and weigh the fish, Burckhardt said. Then each fish is marked by notching its fin.
“We then release them back to the river,” he said.
Later, Game and Fish re-samples the same area and repeats the process, Burckhardt said. The proportion of marked versus unmarked fish allows the department to estimate the overall population size.
Officials from the Willwood Irrigation District, who operate the dam, the Wyoming Department of Environmental Quality, Game and Fish, the Wyoming Water Development Commission and others met Thursday to discuss possible solutions to the silt. Park County commissioners planned to hold a debriefing session today (Tuesday) during their regular meeting.
One possible solution for removing silt built up above the dam would be a flushing flow released from the Buffalo Bill Dam, Burckhardt said.
A large volume of water from Buffalo Bill would dilute the silt, Burckhardt said. Personnel are currently trying to calculate how much water would be necessary. When the volume requirement is figured, Game and Fish can ask the Bureau of Reclamation if the water is available.
The short-term solution must address the sediment behind the dam, Burckhardt said. The longterm goal, he said, would entail reducing sediment entering the Shoshone upstream of the dam to prevent future fish kills.
The answer must provide for Willwood Irrigation District needs while not causing injury to the aquatic species or the fishery; the remedy must be one all can live with, Burckhardt said.
“I think that is what everybody is looking for at this point,” he said.