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. n.r-,,~:~n? u i_p t~ 3 ,) M . Monthly and annual flow contributions from each tributary area vary in response to seasonal patterns and precipitation conditions. Since monthly flow measurements are available for Hermosa Creek, a major tributary of the Animas River with a mean basin elevation of about 9600 feet, it was estimated that other tributary areas at generally the same elevation would have similar streamflow characteristics. For example, the flow of Hermosa Creek was 40 percent of average in 1951, so it is assumed that the flow in Canyon Creek, an ungaged tributary, had a similar flow condition in 1951 . . . A somewhat different monthly streamflow regime typically occurs for drainage basins that are lower in elevation than Hermosa Creek. The monthly flows for ungaged tributaries with mean elevations ranging from 7600 to about 9,000 feet were estimated through use of gage records for Lightner Creek. The Lightner Creek mean basin elevation is 7760 feet. This is the lowest drainage basin in the region that has a fairly long period of streamflow record unaffected by large scale hrigation diversions and return flows. The annual Lightner Creek flows for the 1928 through 1945 period correlate well with the annual Hermosa Creek flows for the same period. The correlation coefficient is 93 percent. . Annual Lightner Creek flows during the 1951 through 1980 study period were estimated to be equal to 17.5 percent of the Hermosa Creek recorded flows. Monthly Lightner Creek stream flows were estimated to have the following monthly distribution based on the 1928 through 1945 gage recOrds: . . Percent of Annual Streamflow . . January February March April May June 0.9 July 3.1 1.3 August 2.2 9.3 September 2.8 35.7 October 3.7 28.0 November 1.8 10.0 December 1.2 Total 100 . Runoff from the relatively low-lying areas adjacent to the Animas River below elevation 7600 feet was estimated through use of Ignacio precipitation -18- . , iL