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within the reach. The sul~t of this report is a 2.5 mile segment hider Creek beginning at its headwaters and extending to Highway 145. (see Figure 1). This segment is located northwest of the Town of Telluride. To date, the staff has received only one recommendation for this reach. • This recommendation is discussed below. Instream Flow Recommendation(s) The CDOW has recommended a 5.25 cfs summer flow and a 1.0 cfs winter flow. Land Status Review Total Length Land Ownershi Upper Terminus Lower Terminus (miles) % Private % Public Headwaters San Miguel River 2.8 15% 85% This segment is approximately 15% public land and °~o private land. 100% of the public land is managed by the USFS (See attached Figure 1). Biological Data The CDOW has conducted field surveys of the fishery resources on this stream and have found a natural environment that can be preserved. As reported for this reach of stream in CDOW'S recommendation letter to the CWCB, Eider Creek was sampled using standard electrofishing equipment approximately 1 mile above the confluence with the San Miguel River. The aquatic sampling summary (See CDOW Fish Survey in Appendix B - on the field data sheet) shows that a self sustaining brook trout fishery exists in Eider Creek. Eider Creek also has a healthy aquatic macroinvertebrate population indicative of high quality water. Eider Creek also supports a • healthy riparian community. Instream flows are needed to preserve and protect these biological communities in addition to the existing brook trout fishery. Eider Creek also produces high quality water that serves to provide assurance that mine clean-up activities in the upper San Miguel basin (above the Town of Telluride) will continue to show improvements to the river's water quality and the river's fish population. Field Survey Data CDOW and CWCB staff used the R2Cross methodology to quantify the amount of water required to preserve the natural environment to a reasonable degree. The R2Cross method requires that stream dischazge and channel profile data be collected in a riffle stream habitat type. Riffles are most easily visualized as the stream habitat types that would dry up first should streamflow cease. This type of hydraulic data collection consists of setting up a transect, surveying the stream channel geometry, and measuring the stream discharge. Appendix B contains copies of field data collected for this proposed segment. Biological Flow Recommendations The CWCB staff relied upon the biological expertise of the cooperating agencies to interpret output from the R2Cross .data collected to develop the initial, biologic. instream flow recommendation. This initial recommendation is designed to address the unique biologic requirements of each stream without regazd to water availability. Three instream flow hydraulic parameters, average depth, percent wetted perimeter, and average velocity, are used to develop • biologic instream flow recommendations. The CDOW has determined that maintaining these three hydraulic parameters at adequate levels across riffle habitat types, aquatic habitat in pools and runs will also be maintained for most life stages of fish and aquatic invertebrates (Nehring 1979; Espegren 1996). -3-