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Biological Data The CDOW has docUlmented the occurr~nce of greenback cutthroat trout in Bear Creek. This population has been shown to be genetically pure (Appendix B). This is significant because greenback cutthroat trout have been identified by the CDOW and federal agencies as "species of greatest conserv~tion need" and are currently listed as "threatened" under the Endangered Spedies Act. I Hydrologic Data I TU conducted a preliminary evaluation of the stream hydrology to determine if water was physically available for an instream flo~ appropriation. Discharge in Bear Creek (Fig. I) was estimated from gage data collected ,by Colorado Springs Utilities (CSU). CSU collected daily discharge data for the pepod of record. The United States Geological Survey (USGS) also maintained a gage on Bear Creek, however, this gage is below the Bear Creek Pipeline diversion and its fl6w estimates are affected by withdrawals from I this structure. On the other hand, the C~U gage is located near the Bear Creek Pipeline at the terminus of the reach proposed for ~rotection and thus provides better estimates of I flows through this reach. Further, the p~riod of record for this gage is longer. Consequently, data from this gage were: used for the water availability analysis. . The water availability analysis used a "later year beginning on 10/1 of the previous year and ending on 9/30 ofthe year of recorq. Only complete water years were included .in the analysis. While the occasional missing data point was not considered a cause for concern, there were some significant data gaps. 1}lthough CSU collected data on Bear Creek from 1/1/49 to 9/30/06, the data from 1/1/66 - 8/29/89 are missing and were therefore excluded. The final water availability a~alysis included the water years 1950 - 1965 and 1990 - 2006. Data from these years we~e used to calculate the average discharge for each day of the year (Fig 2) as well as the average, minimum and maximum daily discharge rate for each month (Table 3). . , The R2CROSS analyses indicated that between November I and April 14 flows should , be at least 0.75 cfs while between April 15 and October 31 flows should be at least 1.8 cfs. According to the water availability ;analysis, estimated average daily flows just above the diversion point (Fig. 2) were alway~ higher than the flows recommended by the R2CROSS analyses. Similarly, for duripg the winter months, 50% of flows exceeded the recommended flows (Table I). However, in September and October the 50% exceedences were 1.69 cfs and 1.38 cfs~ respectively, suggesting that it may make sense to reduce the instream appropriation for these months to 1.3 cfs. Although the 50% exceedence for July was also slightly below the recommend flow of 1.8 cfs, this reflects a I slight dip in the hydrograph before the late summer rains. Because temperatures are frequently high at this time of the year ~nd greenback cutthroat are such an important species, we recommend maintaining in~tream flows at 1.8 cfs throughout July. Further the water availability analysis suggests !that at least 44% of the time there are adequate flows to meet this appropriation. .