WSP08192

• File Number: 8240.200.38.A
• Description: Coordinated Reservoir Operations
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1997
• Author: CWCB
• Title: 1997 Coordinated Reservoir Operations Bypasses for Endangered Fish - Annual Summary of Operations for 1997 to Benefit the Endangered Fishes of the Upper Colorado River Basin
• Water Supply Pro - Doc Type: Publication

I
I
I
I
I
I
I,
I
I
I
I
I
I
I
I
I
I
I
I

between runoff and baseflow periods. Rates of sedimentation were low during summer and fall following
runoff and depth to-embeddedness remained fairly constant through the base flow period. The two years
of initial sampling represents a period of time when both reaches were freshly cleaned of fine sediment
and the data should provide a good baseline for future monitoring. In addition, the USFWS also
conducted its Standardized Monitoring Program.

IX. Issues to Address

. Runoff and Flow Prediction Imnrovements

At present there are 23 SNOTEL sites located in the Upper Colorado River Basin. The sites range in
elevation from 8,700 feet above MSL to I 1,400 feet above MSL. These sites provide a fairly good
indication of what the snow pack is. However, additional information on how melting of the snow pack
translates into stream flows would be helpful. The rough rule of thumb is that when the snow water
equivalent at the SNOTEL sites reaches 10 inches you are at or very near the peak runoff. Refinement of
this approach and better estimates of the melt rate would be beneficial.

The NWS added Extended Streamflow Prediction (ESP) forecasting for the Cameo Gage during 1997.
This added capability should greatly help coordinated reservoir operations during the 1998 runoff.
Furthermore, additional improvements to the extended forecast outlook would be quite helpful and
provide both improved and additional data for use in the ESP model.

Finally, improved communications among all reservoir operators and water administration officials would
help. As a result, the State of Colorado will be implementing the water administration tool as part of
CRDSS in 1999. This tool will help distribute real time information concerning stream flows and
reservoir operations to everyone as soon as it becomes available. The tool may be ready for use in 1998,
but likely not until the runoff season is over.

. Coordination with the Colorado Flood Task Force

The Colorado Flood Task Force continually evaluates the flood potential around the state during the
runoff season. The Task Force employees a private consultant (Henz-Kelly) to provide extended weather
outlooks and also identify areas of potential flood threats. Alternatively, information on reservoir
operations may be useful to the Task Force. The exchange of information between the coordinated
reservoir operations group and the Flood Task Force should be encouraged. In addition, the
documentation of any flooding that may occur is of interest to both groups and coordination of this effort
could help stretch limited financial resources farther.

. Flood Warnings and "Pinch Points" on the River Affecting Coordinated Reservoir Operations

Several stream gages on the river have elevation levels identified on them at which flood warnings are
issued. However, the State of Colorado and NWS do not always agree on what that elevation should be.
The Coordinated Reservoir Operations Group would like to see one set of flood elevation levels identified
for each stream gage upon which both the State of Colorado and NWS agree.

Stream flows during 1997 approached or slightly exceeded bank-full capacity at many locations. Thus,
operations in 1997 defined some of the limitations on Coordinated Reservoir Operations. Photographs
showing flooding along the Colorado River in the Kremmling, Fruita and Cameo areas during 1997, and a
map of these pictures are provided below.

15