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.' aquatic macroinvetebrates indicative of high quality water and it supports a healthy riparian community. The geology of the , Telluride area is unique in that the water of many the San Miguel's tributary streams have extremely low conductivity; in other words, the water quality of nearly all of the San Miguel's tributary streams is extremely pure - pure to the point that electrofishing is not possible with standard electro fishing equipment. Fish may exist in these streams but they are not readily sampled with standard electrofishing gear. The CDOW believes that the lower reaches of these streams are used by fish that are residents of the mainstem San Miguel River and are important to the San Miguel's fish community during some periods of the year (i.e. spawning, rearing, and refugia from high flow events). CDOW also believes that the high quality water that is produced by the tributary streams is extremely important to the impaired water quality of the San Miguel River. Mine drainage into the San Miguel River and mill tailings piles adjacent to the river are currently being cleaned up as a result of comprehensive reclamation effort above the Town of Telluride. Dissolved levels of heavy metals in the San Miguel River continue to be a problem for the river's fishery but conditions are improving; the high quality water from tributary streams such as Royer Gulch are vital to the continued improvement of water quality and the San Miguel's fish population. Flow Quantification Analysis: I reviewed the R2CROSS output for the cross section that was collected on October 8, 1996 by CDOW and CWCB personnel and have developed the following biologically based flow recommendations for Royer Gulch. The flow necessary to meet two hydraulic criteria is 1.3 cfs; this flow is needed to preserve the natural environment to a reasonable degree for the winter low flow season. The flow needed to meet all three hydraulic criteria is 2.7 cfs; this flow is necessary to preserve the natural environment to a reasonable degree during the summer higher flow season. 2.7 cfs falls outside the modeling range of accuracy for the R2CROSS estimate for Manning's "n" so therefore it should not be used until additional field investigations are performed. By default we will use the 1.3 cfs flow recommendation for a year-round flow recommendation and let water availability determine the winter low flow season flow recommendation if your water availability analyses show the 1.3 cfs to be unavailable for some portion of the year. The Division of Wildlife believes that 1.3 cfs will be adequate to preserve and protect the natural environment on Royer Gulch to a reasonable degree. If you have any questions regarding these flow recommendations or the rationale used to develop the flow recommendations, please contact me at your earliest convenience. After you have conducted your water availability analyses for this stream segment, contact me if needed to discuss any technical or biological issues that you encounter. .I! Sincerely, Jay W. Skinner CDOW Instream Flow Program Coordinator cc: Sherman Hebein, CD OW .