Shoshone overrun with silt

Posted 10/25/16

“Words can’t describe what has happened out there,” said Dave Sweet, East Yellowstone Chapter of Trout Unlimited member.

“What’s coming out of the dam can best be described as slurry,” said Jason Burckhardt, Wyoming Game and Fish …

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Shoshone overrun with silt

Posted

River turbidity increase to repair Willwood Dam muddies waters, kills fish

Water the color of greasy gypsum thick with silt from above the Willwood Dam has killed fish and spawned an investigation by the Wyoming Department of Environmental Quality (DEQ).

“Words can’t describe what has happened out there,” said Dave Sweet, East Yellowstone Chapter of Trout Unlimited member.

“What’s coming out of the dam can best be described as slurry,” said Jason Burckhardt, Wyoming Game and Fish Department fisheries biologist in Cody.

Burckhardt said he notified the DEQ of the sediment discharge on Tuesday, Oct. 18.

Willwood Irrigation District obtained authorization from the DEQ for a temporary turbidity increase into the Shoshone River downstream of the dam, said Todd Singbeil, district manager. That was for a $1.6 million project to replace the dam’s penstock and canal gate.

However, “This is not what we intended or authorized when we gave a waiver to the project,” said Keith Guille, DEQ public information officer in Cheyenne. DEQ expects a turbidity increase during construction projects, but impacting aquatic life cannot be allowed, Guille said.

“What we see here would not be allowed under the turbidity waiver,” Guille said. “We take this very seriously. We’re investigating this.”

Burckhardt said his last visit to the area was Friday. “It has the consistency of a milkshake.”

At this point, Game and Fish has not determined how far downstream the fish kill has advanced, or the number of dead fish, Burckhardt said. But, so far dead fish have turned up as far downstream as Eaglenest Creek, Burckhardt said.

Game and Fish has floated the river downstream to Wyo. Highway 295 and Alkali Creek, where the water began clearing, Burckhardt said. When the river clears from the dam and downstream, they will return to survey fish.

What is essential is moving forward while taking appropriate steps to prevent such an event in the future, Burckhardt said. Game and Fish hopes to work with the district and DEQ to ensure it doesn’t happen again. What he’d like to see is the removal of the sediment just upstream of the dam.

That has been studied and the cost estimated at $5.7 million, Singbeil said. The silt arrives from upstream, he said, and nobody thus far has come forward to help mitigate the problem/cost and his district simply cannot afford to remove the silt.

Sediment passing through the dam killed all fish downstream to the confluence of Eaglenest Creek in 2007, Burckhardt said. DEQ ordered the district to pay restitution to Game and Fish.

In the wake of the 2007 silt, the district was supposed to have a sedimentation mitigation plan so it would not happen again, Sweet said.

The problem is there is 23,000 cubic yards of silt behind the dam, Guille said.

“We don’t write tickets,” Guille said. However, he said Willwood could be issued a notice of violation that could result in a penalty or fine, and an order to fix the problem so it does not reoccur.

Willwood had no intention to kill fish, Singbeil said.

The DEQ permit is 45 working days, he said. The contractor is making good progress. “Hopefully it won’t take the full 45 days.” The district is measuring turbidity above and below the dam and he said, “It’s starting to clear itself up a little.”

“We’re concerned too,” Singbeil added.

The Shoshone River is a blue ribbon trout stream, Burckhardt said.

Landowners below the dam are concerned their property will lose value because of the fish kill, Sweet said Monday. “It’s (sediment) probably all the way to Lovell at this point.”

The sediment has choked off insects and is probably impacting aquatic mammals, Sweet said.

DEQ is working with the Wyoming Game and Fish and the Willwood to address the issue, Guille said.

“I would hope that many parties, that have contributed to this problem over the decades and perhaps the operators of Big Horn Reservoir, would like to see this sediment removed from the river channel so it doesn’t end up as downstream disasters in future flushes,” Dave Crowther of Cody said in an email.

Although Crowther is president of the East Yellowstone Chapter of Trout Unlimited, he said he penned his comments as a concerned citizen and not as a representative of the organization.

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