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ATTACHMENT B <br /> Analysis of Factors Contributing to Sediment Loss From the Roads. <br /> Contributing Factors to Sediment loss from roads: <br /> A number of studies have been made of the road system, and factors <br /> which contribute to sediment loss and erosion. <br /> GEO-HYDRO CONSULTING <br /> RECLAMATION OF HAUL ROADS <br /> AND MINE BENCHES. <br /> DOCUMENTATION. <br /> Roads are characterized by long cuts of a considerable height <br /> and corresponding fills. The grade of the roads is steep, <br /> mostly on the order of 8 to 9 percent. <br /> Morphological features of the area have been very much <br /> influenced by the harsh climate related to the exceptionally <br /> high altitude. Erosional processes significantly contributed <br /> to the rugged topography. Frequent avalanches continuously <br /> modify the surface features at numerous locations along the <br /> haul roads and at several mine benches. <br /> As is common in road construction in similar conditions, the <br /> roads were mostly constructed in cuts using the sidecast <br /> method. . . . The road cuts were always excavated as steep as <br /> possible. <br /> It should also be mentioned that the above described road <br /> construction methods . . are very common in other road <br /> construction in mountainous parts of Colorado and other parts <br /> of the U.S. They clearly comprise the most economical method <br /> of construction. They . . . have been used . . . in much more <br /> important highways, such as the state of Colorado highways, or <br /> even during the construction of interstate highways. <br /> The maintenance of the roads is required for other reasons <br /> than stability (correction of erosion problems, maintenance of <br /> the road ditch, cleaning of rockfall, snow removal, avalanche <br /> mitigation) . <br /> The region which includes Coal Basin is historically an <br /> avalanche prone area. The steep gullies and cliffed slopes <br /> formed by the sedimentary rocks, combined with the frequent <br /> heavy snowfall common to the region, encourage the development <br /> of unstable snow. <br /> 1 <br />