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<br />Biological Data
<br />
<br />Colorado Division of Wildlife (CDOW) conducted field investigations of Middle, East, and
<br />mainstem Escalante Creek (CDOW 1977), Due to low flow conditions during the time of
<br />sampling, no fish were found in Middle Fork and East Fork Escalante Creek. However speckled
<br />dace have been observed in small pools in Middle Fork Escalante Creek during 2003 (James
<br />pers, comm,), Bluehead and flannelmouth suckers, speckled dace, rainbow trout, and fathead
<br />minnows were captured in the mainstem of Escalante Creek (CDOW 1977), Biomass was
<br />highest for bluehead suckers in the lower reach and rainbow trout in the upper reach,
<br />Additionally, CDOW has stocked all three streams frequently since 1973 (Appendix B),
<br />
<br />Habitat conditions for both East Fork and Middle Fork Escalante Creeks are good, A healthy
<br />willow community exists along both streams, with good stream cover, primarily undercut banks,
<br />boulders, and overhanging vegetation, Fine sediment is high in the lower reaches of both
<br />streams, but lessens as the stream moves higher upstream into USFS lands, Temperatures are
<br />also warmer in the lower portions of both streams, but cool in the higher elevations, During the
<br />summer, water tables are higher in the upper portions of the watershed, with more surface water
<br />in the upstream portions of the stream, and more intermittent or low flow conditions toward the
<br />lower terminus of both East Fork and Middle Fork Escalante Creeks,
<br />
<br />Field Survey Data
<br />
<br />USFS staff used the R2Cross methodology to quantify the amount of water required to preserve
<br />the natural environment to a reasonable degree, The R2Cross method requires that stream
<br />discharge and channel profile data be collected in a riffle stream habitat type, Riffles are most
<br />easily visualized, as the stream habitat types that would dry up first should streamflow cease,
<br />This type of hydraulic data collection consists of setting up a transect, surveying the stream
<br />channel geometry, and measuring the stream discharge, Appendix B contains copies of field
<br />data collected for this proposed segment.
<br />
<br />Biological Flow Recommendation
<br />
<br />The CWCB staff relied upon the biological expertise of the cooperating agencies to interpret
<br />output from the R2Cross data collected to develop the initial, biologic instream flow
<br />recommendation, This initial recommendation is designed to address the unique biologic
<br />requirements of each stream without regard to water availability, Three instream flow hydraulic
<br />parameters, average depth, percent wetted perimeter, and average velocity are used to develop
<br />biologic instream flow recommendations, The CDOW has determined that maintaining these
<br />three hydraulic parameters at adequate levels across riffle habitat types, aquatic habitat in pools
<br />and runs will also be maintained for most life stages of fish and aquatic invertebrates (Nehring
<br />1979; Espegren 1996),
<br />
<br />For this segment of stream, two data sets were collected with the results shown in Table 1 below,
<br />Table 1 shows who collected the data (Party), the date the data was collected (Date), the
<br />measured discharge at the time of the survey (Q), the accuracy range of the predicted flows
<br />based on Manning's Equation (240% and 40% of Q), the summer flow recommendation based
<br />on meeting 3 of 3 hydraulic criteria and the winter flow recommendation based upon 2 of 3
<br />hydraulic criteria,
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