Flushing flows to begin on Colorado River Wednesday morning
October 5, 2010
HOT SULPHUR SPRINGS – The Colorado Division of Wildlife is alerting anglers and other users of the Colorado River through Grand County to be aware of a river rehabilitation project that will create unseasonably high flows beginning today, Wednesday, Oct. 6.
The increased flows are designed to restore channel conditions favorable to trout after an August silt removal project by Windy Gap’s owner, Northern Water’s Municipal Subdistrict.
The project required lowering the reservoir’s level, which increased sediment flow into the river below the dam.
Biologists predict a “flushing flow” beginning Wednesday morning will assist in clearing sediment prior to the brown trout spawn in mid-October.
“Despite taking numerous precautions to minimize the amount of sediment moving downstream of Windy Gap during the silt removal project, some did make its way down,” said Northern Water General Manager Eric Wilkinson. “We’re happy that we have the water available to help improve trout habitat.”
Beginning Wednesday morning, releases from the dam will increase the river’s flow to 450 cubic feet per second. Outflow from the dam will then be stepped down through Friday, returning the river to normal seasonal levels.
The Colorado River near Parshall is currently running at approximately 190 cfs.
The expected 450 cfs flow is well below the river’s capacity, which can peak above 2,500 cfs during peak spring runoff.
Prior to the Windy Gap releases, the U.S. Bureau of Reclamation and Northern Water will begin releasing Windy Gap project water, which has been temporarily stored in Granby Reservoir.
Increased flows may make it more difficult for anglers fishing the river and may create unsafe conditions for fly fishermen on Wednesday, Thursday and Friday on the stretch of river from Windy Gap to Gore Canyon.
The areas where higher-than-average flows will be seen include the Colorado River through Hot Sulphur Springs and Kremmling. Anglers fishing Gore Canyon or beyond are unlikely to be affected by the increased flow because river topography and additional in-flows from other waters will minimize the impacts.
The project is a cooperative effort between Northern Water’s Municipal Subdistrict, Grand County, the Bureau of Reclamation and the Division of Wildlife.
Windy Gap project
The Windy Gap silt removal project began on Aug. 20 when the reservoir was drained to allow backhoes to scrape 7 to 9 feet of silt that had collected at the front of gates at the pump plant. The pile of silt had managed to bend the shafts of the gates, which cost about $30,000 to replace, according to Northern spokesperson Dana Strongin.
About 750 truckloads of silt were carried out of the reservoir bottom and were given to Grand County to be mixed with mulch for revegetation of its closed landfill site near Windy Gap, Strongin said.