ISFAPPC01442 ‎(2)‎

• Case Number: 04CW0087
• Stream Name: Thirtyone Mile Creek
• Water Division: 2
• Water District: 12
• County: Park
• Instream Flow App - Doc Type: Supplemental Data

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IN REPLY REFER TO:

United States Department of the Interior

BUREAU OF LAND MANAGEMENT
Colorado State Office
2850 Youngfield Street
Lakewood, Colorado 80215-7093

www.co.blm.gov

CO-932
7250

DEe 1 7 2003

Mr. Dan Merriman
Colorado Water Conservation Board
1313 Sherman Street, Room 721
Denver, Colorado 80203

Dear Mr. Merriman:

The Bureau of Land Management (BLM) is writing this letter to formally communicate its
instream flow recommendation for Thirtyone Mile Creek, located in Water Division 2.

Location and Land Status. The Thirtyone Mile Creek watershed is located approximately 30
miles east of Buena Vista. The stream reach that was surveyed begins at the headwaters and
runs 9.7 miles downstream to the confluence with Currant Creek. Approximately 60% of the
reach is owned and managed by BLM, while the remaining 40% is in private ownership.

Biological Summary. The stream environment appears to be in stable condition and is
improving in some locations as a result of recently changed grazing practices. Substrate, water
quality, channel stability, and food supplies are good for salmonids. However, bank stability and
lack of cover are limiting conditions in some portions of the reach, contributing to occasionally
high stream temperatures. Accordingly, maintaining adequate stream flow is important for
preventing late summer fish kills. Fish surveys indicate that the reach supports a self-sustaining
population of brook trout, long-nose dace, and white suckers.

R2Cross Analysis. BLM's data analysis, coordinated with the Division of Wildlife, indicates
that the following flows are required to protect the fishery and natural environment to a
reasonable degree:

1.00 cubic feet per second is recommended for the April 15 to October 31 high
temperature period. This recommendation is driven by the average depth criteria.
Meeting the depth criteria is important for insuring that the fish population has access to
spawning gravels in a stream that has steep gradients and narrow widths.

0.35 cubic feet per second is recommended for the November I to April 14 low
temperature period. Maintaining adequate velocity is important for maintaining ice-free
riffles for fish passage during icing period in the winter.