ISFAPP01508

• Year: 1996
• Title: Development of Instream Flow Recommendations in Colorado Using R2CROSSDevelopment of Instream Flow Recommendations in Colorado Using R2CROSS
• CWCB Section: Stream & Lake Protection
• Author: Gregory D. Espegren
• Description: Overview of Colorado's ISF Program and documentation for the R2CROSS Lotus macro
• Publications - Doc Type: Historical

Figure A.

Typical stream cross section

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tape Lew:I refenD:e line

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Bioloiic Data Collection
Biologic sampling is conducted to
document the existence of a natural
environment. C~ldwater fish. species,
particularly salmonids, have been used to.
indicate the existence of such a natural
environment in the majority of the CWCB's
instream flow appropriations to date.
Warmwater fish species and other aquatic life
forms may be used to document the existence of
a natural environment in more downstream,
low-elevation stream segments. In addition to
salmonids, the CWCB has used amphibians,
such as frogs and salamanders, and warmwater
fish species, including the endangered fishes of
the Colorado River basin, as the biologic basis
for instream flow appropriations.
Biologic data typically consists of a fish
sample, collected by electroflShing, and an
aquaticin~~matesamp~.C~ruredfuhare
identified and measured and a length-frequency
distribution is constructed for each species. The
sample is not tied directly to the R2CROSS
hydraulic modeling but it may be used to refine
the biologic instream flow recommendation to

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meet the specific-habitat requirements of unique
populations.

The Field Form
The CWCB and DOW use a
standardized field form to record all field data.
The use of this form helps to ensure that all
instream flow recommendations are based upon
a uniform set of field data. The front page of
the form provides space for cross section
"Location Information", "Supplemental Data",
"Channel Proflle Data", an "Aquatic Sampling
Summary", and "Comments" (Figure B). The
back page is dedicated to "Discharge/Cross
Section Notes" (Figure C).
The "Location Information" section of
the field form is used to describe the location of
the cross section as well as the date and names
of the members of the field crew. Geographic
information can be obtained from either USGS
or United States Forest Service (USFS) maps.
Water divisions and DQW water codes can be
obtained from the State Engineers' Office, the
CWCB, or the DOW.

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