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<br />range of the R2CROSS model is 1.0 cfs (See Table I). It is our beliefthat recommendations that <br />fall outside of the accuracy range of the model, over 250% of the measured discharge or under <br />40% ofthe measured discharge may not give an accurate estimate ofthe necessary instream flow <br />required. <br /> <br />Hydrologic Data <br /> <br />After receiving the cooperating agency's biologic recommendation, the CWCB and BLM staff, <br />conducted an evaluation of the stream hydrology to determine if water was physically available <br />for an instream flow appropriation. Although there is a substantial amount of streamflow gage <br />data available for the Uncompahgre Plateau and Glade Park, most of this data is severely <br />impacted by diversions and irrigation use. This situation makes it difficult to estimate the natural <br />flow regime for the watersheds on the Plateau. Without specific gage data to evaluate, the next <br />best approach is a regional equation that estimates annual flow characteristics. The USGS has <br />developed regional equations (Estimation of Natural Streamflow Characteristics in Western <br />Colorado. Water Resources Investigations Report 85-4086.1985) that apply to the Uncompahgre <br />Plateau and Glade Park based on basin drainage area, mean annual precipitation, mean basin <br />elevation and mean basin slope. The report "Uncompahgre Plateau and Glade Park Annual <br />Hydrograph Estimation" in Appendix C, explains staff's water availability analysis in more <br />detail. Table 2 below displays the estimated stream flow of North East Creek. <br /> <br />Table 2: North East Creek estimated streamflow. <br /> <br />Januarv Februarv March <br />0.69 1.5 2.2 <br /> <br />Aptll <br />33 <br /> <br />May <br />120 <br /> <br />June <br />55 <br /> <br />Julv <br />2.. <br /> <br />August September October November December <br />1.1 0.89 0.84 0.82 0.75 <br /> <br />North East Creek Estimated Stream Flow <br /> <br />8.0 <br /> <br />6.0 <br /> <br />~ 4.0 <br /> <br />2.0 <br /> <br />~---- <br />-- <br /> <br />'- <br />- ---~ <br /> <br />0.0 <br /> <br />JAN <br /> <br />FEB <br /> <br />MAR <br /> <br />APR <br /> <br />MAY <br /> <br />JUN <br /> <br />JUL <br /> <br />AUG <br /> <br />SEP <br /> <br />OCT <br /> <br />NOY <br /> <br />DEC <br /> <br />Month <br /> <br />Table 2 shows that the summer flow recommendation of 5.0 cfs not available from April 15t <br />through June 30th. Table 2 also shows that the winter flow recommendation of 1.0 cfs is only <br />available from July 1st through August 31" and February 1st through March 31". The winter flow <br /> <br />-4- <br />