The UCRWG August Snapshot looks at stream flows and water temperatures across Grand County, with a focus on the number of high water temperature days over the previous 31 day period.
Flows were low throughout much of the Upper Colorado River basin when we took our monthly snapshot on August 14th, with ongoing drought conditions and high temperatures in July and August elevating stream temperatures throughout much of the watershed and state of Colorado. Elevated flows released from Lake Granby were reflected in the Colorado River west of Kremmling, with higher water volumes keeping temperatures just below the 68°F/20°C mark for fish downstream.
Cooler waters on Muddy Creek just below Wolford Reservoir are marked by the green cross just north of Kremmling, where temperatures were within the safe zone for trout, though overall flow levels were still lower than normal. The benefits of extra water released on the Colorado River near Pumphouse can be seen by the blue dot just southwest of Kremmling, where flows are elevated in an effort to protect endangered fish much further down the Colorado River. While the extra water lowers temperatures a bit, waters are still warm enough to stress trout. Stream temperatures in excess of 65°F/18°C stress native trout adapted to cooler waters, while waters above 70°F/21°C result in trout having difficulties using oxygen.