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The revised New Horizon 2 permit area is located in the water sheds of both Tuttle Draw and <br />Calamity Draw. The revised New Horizon 2 permit area to the south and east of the West Lateral <br />irrigation ditch drains into Calamity Draw and consists of 396 acres. The area north and west of <br />the West Lateral irrigation ditch drains into Tuttle Draw and consists of 412 acres. The drainage <br />area of Calamity Draw to its confluence with the San Miguel River is about 7.0 square miles. The <br />drainage basin of Tuttle Draw is about 16 square miles. With the exception of the lower portion <br />of the Calamity Draw basin (nearthe mouth), the watershed is largely comprised of irrigated pasture <br />and rangeland (First Park) and to a lesser extent, the townsite of Nucla, Colorado. The middle and <br />upper portions of Calamity Draw Basin have been intensively irrigated and cultivated since the early <br />1920's and late 1910's. The development of the townsite and corresponding spread of cultivated <br />and irrigated fields has resulted in a disjoint tributary drainage pattern almost completely controlled <br />by the return ditches of the irrigation network. These return ditches (tributaries) in the mid- and <br />upper portion of Calamity Draw are mostly intermittent and possibly perennial and are largely <br />influenced by the timing and application of irrigation water. The overall average basin slope of <br />Calamity Draw is about 76 feet per mile, with an average basin elevation of 5,857 feet above MSL. <br />For the basin area in Calamity Draw above the location of surface water monitoring Site SW-N1 03 <br />(see Map 2.04.7-1A Hydrologic Monitoring Site Location Map), the average basin slope is <br />approximately 48 feet per mile. This suggests that since the onset of man's activities in the upper <br />portions of Calamity Draw (cultivation of land and the establishment of the townsite), these activities <br />have greatly influenced the basin geomorphology of this watershed. <br />The Tuttle Draw drainage consists of both non-irrigated grazing areas and irrigated cultivated land. <br />The drainage area above Nucla and the intersection of the Second Park irrigation ditch and the <br />West Lateral irrigation ditch is non-irrigated range land developed on the more steeply dipping <br />slopes of the southwest flank of the Uncompraghre Uplift. Tributaries to Tuttle Draw in this area <br />incise the dip slopes resulting in local topographic relief of up to 200 feet (Spradlin Park area). This <br />produces a moderately sloping rough mesa and canyon topography in this area with the mesa tops <br />(dip slopes) sloping to the southeast at about 320 feet per mile. Below Nucla and the intersection <br />of the two irrigation ditches, slopes are more moderate and the flatest land is irrigated. Tributaries <br />to Tuttle Draw along the northern flank of First Park typically have local topographic relief of 100 <br />feet or less. The mesa to the south of Tuttle Draw located in the revised New Horizon 2 permit area <br />slopes generally to the west at about 130 feet/mile. The lower reaches of Tuttle Draw are steeper. <br />Topographic relief at the mouth of Tuttle Draw is about 300 feet. The Tuttle Draw drainage area <br />encompasses elevations from 6580 feet to 5240 feet with an average gradient of about 140 <br />2.04.7-29