Colorado Parks and Wildlife officials are asking people to avoid fishing along part of the Colorado River due to warmer water temperatures, low flow, and sediment buildup.
The agency made the voluntary ban effective on Wednesday, and it affects a stretch of the Colorado River between the municipalities of Kremmling and Rifle but could include other rivers depending on temperature increases.
Officials are concerned about warmer water temperatures, which provide less oxygen for fish to breathe. The agency has already noticed some fish dying from the warmer water.
Officials also noted that sediment buildup from flash flooding and mudslides stemming from the prior year’s wildfires pose another problem for fish.
“With the high sediment load, the fish can’t find clear water,” CPW Aquatic Biologist Kendall Bakich said in a statement. “They’ve got to sit through those conditions. And at nighttime, the temp isn’t coming down enough, so there’s no recovery for those fish right now. They’ve just got to hang on.”
The agency said that recorded river flows are also lower than normal because of a major drought. The U.S. Geological Survey’s gauge at Catamount Bridge along the Colorado River usually measures at between 1,500 and 2,000 cubic feet per second, but the agency noted that it has recently been measuring half of that amount between 600 and 700 cubic feet per second.
At another stretch of the river near the community of Dotsero also a geological gauge measured the river flow at 1,250 cubic feet per second, compared to its expected 3,000 - 4,000 cubic feet per second.
The agency said it may consider a volunteer closure along a stretch of the Yampa River if the temperature hit 75 degrees on Wednesday as it already had the day before.
“We’re asking folks to voluntarily refrain from fishing,” Travis Duncan, spokesman for Colorado Parks and Wildlife, told the Associated Press. “If the conditions persist, we’ll need to adopt a mandatory ban.”