BOARD00568

• Board Meeting Date: 1/27/2004
• Description: ISF Section - Instream Flow Appropriations - Thirtyone Mile Creek
• Board Meetings - Doc Type: Memo

1:-1 REPLY R&ER TO: I

United States Department of the Interior

BUREAU OF LAND MANAGEMENT
Colorado Slate Office
2850 YoungfieId Strcet
Lakewood, Colorado 80215-7093

U8.BEPAAlJ,IEtHOFTliEINTEAIOA
BUfll'AUOF~AHD"'A~""E"'E~T

---:.:.. ~.r'J-=--

www.co.blm.gov

CO-93t
7250 I

U~~(; 1 7 12~:U3

Mr. Dap Merriman
Colora<fo Water Conservation Board
13 13 Sherman Street, Room 721
Denverl Colorado 80203

Dear Mr' Merriman:

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

Locatiqn and Land Status. The Thirtyone Mile Creek watershed is located approximately 30
miles e~st of Buena Vista. The stream reach that was surveyed begins at the headwaters and
runs 9."l1 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.

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

R2cro~s 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
reasonatle degree:

1.00 cubic feet per second is recommended for the April 15 to October 31 high
~emperature 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
~pawning gravels in a stream that has steep gradients and narrow widths.

~.35 cubic feet per second is recommended for the November 1 to April 14 low
~emperature period. Maintaining adequate velocity is important for maintaining ice-free
rffles for fish passage during icing period in the winter.

I
~

~
II