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COL-2: LOWER COLORADO RIVER SUBREGION This subregion includes the Colorado River mainstem and its tributaries in the watershed areas downstream of Glenwood Springs (downstream of the Colorado River confluence with the Roaring Fork River), Streams in this subregion are located to the west of the Continental Divide within Mesa County and Garfield County. Major tributaries in this subregion include the Roan Creek and Rifle Creek. The subregion is bounded as follows: Subregion COL-2 is Under Construction COL-3: LOWER GUNNISON RIVER SUBREGION This subregion includes the Gunnison River mainstem and its tributaries downstream of the City of Gunnison. Streams in this subregion are located in portions of Gunnison County, Delta County, Mesa County, Montrose County, Ouray County, Hinsdale County, and Saguache County. Major tributaries in this subregion include the North Fork of the Gunnison River and Uncompahgre River. This subregion does not include the East River, Taylor River, Ohio Creek, and Tomichi Creek basins. The subregion is bounded as follows: . On the north by the Gunnison River - Colorado River basin divide; . On the east by the basin divide between the North Fork Gunnison RiverlBeaver Creek and Ohio Creek/East River; . And on the east by the basin divide between Cebolla Creek/South Beaver Creek and Tomichi Creek; . On the south by the Gunnison River - Rio Grande/San Juan River basin divides; and . On the west by the Gunnison River - Dolores River basin divide. The regression equation for this subregion is only valid for natural tributary slreams that have drainage areas between 2 mi2 and 8,000 mi2. A detailed study or other hydrologic analysis must be performed for projects involving slreams with drainage areas that fall outside of the applicable range. The equation for subregion COL-3 is: Q = 180.8(A).578 Where: A = Drainage Area, square miles (2<A<8,000) Q = 100 year peak flow, cfs 23