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EXECUTIVE SUMMARY <br />Engineering and geomorphic analysis of the Colorado Yampa Coal <br />Company Eckman Park Mine provides the following conclusions: <br />1. Existing slope gradients are not significantly different from <br />approved slope gradients. <br />2. Drainage density (number of drainages per square mile) is within <br />the limits of natural variation of drainage density and, <br />therefore, has not been altered significantly. <br />3. The swale at the upper portions of the mine does not constitute <br />a significant departure from the approved plan and it is not <br />inconsistent with surrounding natural landforms. <br />4. Erosive power of stream channels has not been significantly <br />changed by mining and reclamation except for specific areas <br />• where channel gradient has been increased. <br />5. The majority of existing and approved channels are stable for <br />the 10-year, 24-hour event (assuming a 12 foot channel 'width) <br />except for isolated reaches with increased gradient. <br />6. Vegetation is important in maintaining long term stability. <br />Objective geomorphic and engineering analysis of the Eckman Park <br />Mine indicates that the existing topography is not significantly <br />different from the approved postmining topography. Several isolated <br />reaches of reclaimed stream channel are significantly more erosive than <br />approved stream channels due to an increase in channel slope. These <br />reaches will require application of one or more mitigation alternatives <br />• in order to reduce the potential for erosion. <br />v <br />