October Watershed Snapshot
Flows were low across the Upper Colorado River watershed throughout October, as the summer drought stretched into fall. Luckily, cooler weather from the season change kept water temperatures nice and cold for the alpine aquatic life.
From mid September to mid October, we are starting to see normal low flow conditions in most of the rivers in the Upper Colorado River Watershed. Elevated flows are seen below Lake Granby and Ranch Creek to send extra water downstream for endangered fish. Cooler air temperatures have brought the water temperatures down into safe levels for fish. As a result, temperature is not being reported on the map. Most sites in upper elevations are low as a result of our dry summer and fall. Fishing active lures and streamers will continue to be good until ice starts to form on lakes and streams. Is your ice fishing gear ready? Read More
From mid August to September, we saw temperatures begin to cool as fall begins. The Fraser River near Tabernash only had one day where water temperature was in excess of 68°F/20°C.
Flows were elevated in Ranch Creek and on the Colorado River below Lake Granby to send more water downstream. Muddy Creek above Wolford Reservoir was still problematic with water temperature going over the critical 68°F/20°C on 10 days out of the previous month-long period.
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.
Water temperatures were high across most of the Upper Colorado River Watershed in July,
with low flows in key parts of the watershed from trans-basin diversions. Over 500 cubic feet per second (CFS) were diverted to the Front Range through the Moffat and Adams tunnels, marked by the purple lines on the right side of the map.
Flows at Windy Gap represent water sent further downstream, with only 176 cfs flowing further down the Colorado in mid-July. The red dot to the left of Granby marks Windy Gap Reservoir, where the two major confluences of the Upper Colorado River – the North Fork and the Fraser – meet.