Low water flows and warm temperatures have prompted a voluntary fishing closure on the Conejos River in the afternoon, Colorado Parks and Wildlife said Thursday.

This voluntary closure is in place for the section of the Conejos River from Platoro Reservoir to Broyles Bridge until further notice, and CPW did not rule out the possibility of an emergency closure if conditions worsen. The river is in the San Luis Valley in south-central Colorado.

The U.S. Geologic Service is reporting low flow rates throughout Southwest Colorado. The Dolores River on Friday was flowing at 107 cubic feet per second in Dolores, down 49 percent from a daily average of 209 cfs. The Animas River was at 131 cfs in Durango, down 73 percent from a daily average of 482 cfs. Water temperatures were approaching highs of 69 degrees and lows of 58 degrees.

“The Conejos River is one of Colorado’s most renowned trout streams,” said John Alves, senior aquatic biologist. “We know that anglers care deeply about this fishery, and we need their help to conserve this resource.”

Water flows from the outlet at Platoro Reservoir have declined to about 10 cubic feet per second, down from 60 cfs. Last year’s snowfall was less than 50 percent of average in the Rio Grande basin.

Water temperature is also a concern. Afternoon river temperatures have risen to 70 degrees, which is unhealthy for trout. Since water temperatures cool overnight, fishing during the morning will help to minimize impacts to trout.

CPW also warned that catch and release can be stressful and even deadly for fish in low, warm water because of the decreased oxygen in the water.

Brown trout, the predominant species in the river, spawn in the fall; so the current river conditions could impact spawning activities.

“This is the first time we’ve made this kind of voluntary-action request on the Conejos. It’s not something we like to do, but it’s the right thing to do, and we hope anglers will join us in this conservation effort,” Alves said.