BOARD00970

• Board Meeting Date: 7/22/1993
• Description: Agenda or Table of Contents, Minutes, Memos. Partial.
• Board Meetings - Doc Type: Meeting

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QUANTIFICATION SUPPLEMENT - UTILE DRY CREEK
July 1, 1993
PAGE 5

distributed, the Division feels that this conservative approach is both proper and
appropriate. While these species are not as "glamorous" as a 20 inch brown trout or a wild
rainbow trout fishery, these species fill an important ecological role in the stream ecosystem
of Little Dry Creek. The data collected on Little Dry Creek suggests that a flow of 2.2 cfs
will preserve and maintain the existing fish populations. An appropriation of 2.2 cfs will
also preserve the other aspects of the water dependant natural environment described in the
NATURAL ENVIRONMENT section of the April, 1993 report.

In addition to the fishery, the work of Dr. David Cooper (attached to the April, 1993
report) suggests that a flow of 2.25 cfs will maintain the riparian vegetation and associated
wetlands.

HYDROLOGY

All of the flow measurements that were done over the course of this study as well as
the water availability analyses conducted by the CWCB staff suggest that this stream is not
typical of Colorado streams. The hydrograph for Little Dry Creek is essentially a flat line.
It is not a typical snowmelt driven system; rather, it is a base flow system which reacts to
local storm events and local snowmelt. It is therefore the feeling of the Division that no
biological or hydrological reason exists for the seasonal split flow that was previously
recommended.

RECOMMENDATIONS

The Division therefore recommends to the CWCB that a Final Notice of Instream
Flow Recommendations be mailed with a flow recommendation for Little Dry Creek in the
amount of 2.2 cfs for the entire year. This flow recommendation is good for the reach of
stream from the confluence of Little Dry Creek and Willow Creek downstream to the bridge
at Clarkson Street.