A year after a huge mud spill killed fish below the Willwood dam near Cody, another sediment release is muddying the Shoshone River now. But, Wyoming’s Department of Environmental Quality says this year’s sediment release is being monitored and several groups are working together to prevent damage to the Shoshone River.
The spill in October 2016 turned the Shoshone River water chocolate brown.
Dead fish were found on the river banks. Anglers, a Cody outfitter, and a nearby homeowner complained. Wyoming’s Department of Environmental Quality issued a notice of violation to the Willwood Irrigation District, and the federal Bureau of Reclamation.
The district released the muddy water to repair the dam. The Bureau owns the dam.
Game and Fish Fisheries biologist Jason Burckhardt said the reservoir above the dam is being drawn down now to protect the gates from freezing.
He explained, “Turbidity will go up but it will be back to the standards that we put in place prior to last year, so they will not exceed 10 NTU’s above ambient. That will protect the spawning brown trout that are downstream from the dam, as well as the mountain white fish, and all of the cutthroat and rainbow that are down there as well.”
The DEQ says state and federal agencies are working with the irrigation district, and conservation groups avoid another spill like the one that happened last year.