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<br />Instream Flow Recommendation(s) <br /> <br />The CDOW has recommended 1.0 cfs, year-round, based on their data collection efforts (see <br />Table 1 and Appendix A). The modeling results from this survey effort are within the <br />confidence interval produced by the R2CROSS model. <br /> <br />Land Status Review <br /> <br /> Total Length Land Ownership <br />Upper Terminus Lower Terminus (miles) % Private % Public <br />BLM-Private Paonia Reservoir 0.95 0% 100% <br />Boundary <br /> <br />100% of the reach is located on public lands managed by the BLM and the other 0% of the reach <br />is located on private lands. <br /> <br />Biological and Field Survey Data <br /> <br />The CDOW has conducted field surveys of the fishery resources on this stream and have found a <br />natural environment that can be preserved. As reported in the letter from CDOW to the CWCB <br />"Field surveys indicate that the stream environment is presently in stable condition, and could <br />support a coldwater fishery. Channel stability, bank stability, and substrate is good. This type of <br />stream environment has steep gradients that typically limit the available pool habitat and food <br />supply. Accordingly, it is important to provide stream flows that protect the limited amount of <br />available habitat. Williams Creek is classified as a minor stream (between 4 to 9 feet wide) and <br />fishery surveys of other streams tributary to Paonia Reservoir indicate the stream environment of <br />Williams Creek should support populations of white suckers, bluehead suckers, fathead <br />minnows, speckled dace and mottled sculpins." (See CDOW Fish Survey in Appendix B). <br /> <br />Field Survey Data <br /> <br />CDOW staff used the R2CROSS methodology to quantify the amount of water required to <br />preserve the natural environment to a reasonable degree. The R2CROSS method requires that <br />stream discharge and channel profile data be collected in a riffle stream habitat type. Riffles are <br />most easily visualized, as the stream habitat types that would dry up first should streamflow <br />cease. This type of hydraulic data collection consists of setting up a transect, surveying the <br />stream channel geometry, and measuring the stream discharge. Appendix B contains copies of <br />field 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, one data set was 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 /> <br />- 3 - <br />