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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INSTREAM FWW QUANTIFICATION - LITTLE DRY CREEK
April 5, 1993
PAGE 20

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population and the wildlife inventory for this corridor suggest that this is an important natural
environment which depends upon the flowing water to sustain the ecosystem as a whole. These
are the underlying principles which guide the following flow recommendations.

Flows in the range of 2 cfs to 3.5 cfs maintain 70% to 75% of the adult habitat for all
three species of fish at the two IFIM sites. It is therefore the recommendation of the Division
of Wildlife that 2.75 cfs be maintained during the higher flow periods. Flow measurements on
Little Dry Creek that were collected over the course of this study suggest that this amount of
flow is in the system for the period of April through August. This flow should maintain
adequate habitat for the existing adult fish population. In addition, this flow should be adequate
for the maintenance of the fry and juvenile life stages for the two species for which habitat was
modeled.

Flow monitoring (APPENDIX D) and spot measurements conducted by the DOW suggest
the flows during the winter months are much lower than 2.75 cfs. Many of the pools and
undercut banks along Little Dry Creek are in large, long backwater sections. This habitat is
maintained during the winter months by the limited stream flow; therefore a lower winter flow
recommendation is sound from both a hydrological and biological standpoint. The data suggests
that a winter flow of 1.75 cfs still maintains 30% to 55% of the adult fish habitat.

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The above flow recommendations are consistent with the recommendations of Dr. Cooper
as well. Recall that his recommendations were to: 1) maintain a minimum stream flow of
approximately 2.25 cfs, 2) maintain the peak flows (over which the Instream Flow Program and
no one else has any control), and 3) make sure that the stream is not allowed to go dry. An
instream flow water right is an important first step towards recommendation 3) realizing that
there may be senior water rights that may be able to divert water out of the creek. In closing,
this instream flow recommendation, while quantitatively developed with the fish population as
its primary focus, should also protect other aspects of the water dependant natural environment,
such as the riparian zone, the birds and waterfowl, and the terrestrial wildlife community of
Little Dry Creek.

CONCLUSIONS

To reiterate, based on the studies that have been conducted by the Division of Wildlife
and others, the Division offers the following conclusions and recommendations:

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That there is a natural environment in and around Little Dry Creek
upstream of Downing Street. Supporting documentation of that natural
environment is either attached to this report or is available for inspection at
the Division of Wildlife.

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