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. . . Instream Flow Recommendation(s) BLM's instream flow recommendation is for 93 cfs (May 1 - October 14) and 61 cfs (October 15 - April 30). Land Status Review Upper Terminus Fall Creek Lower Terminus Horsefly Creek Total Length (miles) 24.1 Land Ownershi % Private % Public 40 % 60 % Approximately 99% of the public lands within the reach are managed by the BLM. Biological Data In 1999, the Colorado Division of Wildlife conducted an extensive fisheries inventory in the San Miguel River basin, Throughout this reach of the San Miguel River a healthy cold water fishery exists, The 1999 inventory and other historic biological information show brown trout, rainbow trout, brook trout, Colorado River cutthroat trout, Snake River cutthroat trout, mottled sculpin, speckled dace, longnose dace, bluehead sucker, roundtail chub, black bullhead, and fathead minnow to be present in the San Miguel River. In the section that is the subject of this flow recommendation, brown trout and rainbow trout are the most numerous species of fish present in the San Miguel River between Fall Creek and Horsefly Creek. The rainbow and brown trout populations are sustained by both stocking and natural reproduction. This segment of the San Miguel contains one of the three longest stretches of good condition riparian vegetation in the montane region of western Colorado, It contains examples of a blue spruce - narrow-leaf cottonwood - thin-leaf alder - water birch riparian plant community that is known to occur in only seven locations in Colorado, Included in the segment are relic riparian sites that are believed to be in pre-settlement condition, The riparian community is directly dependent on the natural runoff pattern still exhibited by the river. It is therefore the opinion of the CWCB staff and the recommending agencies that a natural environment exists and that this natural environment can be preserved to a reasonable degree with an instream flow water right. For more specific information regarding the aquatic resources sampled in the San Miguel River, see the CDOW historic fish data and 1999 Inventory Report in Appendix B. Also included in this report is an extensive record of fish stocking in the San Miguel by the CDOW. Field Survey Data CDOW and BLM 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 discharge 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 Recommendation 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 regard to water availability. Three instream flow hydraulic