2012-11-05_REVISION - C1982056 (5)

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Cover The ability of the proposed seed mixtures to control erosion is directly related to the vegetative cover produced by the planted species. Using the data available from the aforementioned bond release area, optimal premining cover was described by the Soil Conservation Service as 35 percent. Data taken in 1977, three years after seeding, indicated that the total cover on this site amounted to 39 percent. Plant cover data taken in 1979 indicated that the total cover on the site was 89 percent. Comparison of the reclaimed cover values to vegetative cover values described under Rule 2.04.10 indicates that approximately three years were required at the bond release site seeded in 1974 before total ground cover values were similar to premining values. utilizing the improved revegetation practices proposed in this permit application, it is estimated that cover will reach premining levels in substantially less than three years time. The plant species proposed for the two permanent seed mistures are capable of providing the soil stabilization needed to control erosion. From the standpoint of ground cover, the erosion potential of successfully revegetated mined land should not exceed the rate of geological erosion found on adjacent natural areas. Woody Plant Density In order to better achieve the goals of the postmining land use, Twentymile Coal Company requests the Division to approve a woody plant density of 1,000 stems per acre for areas to be reclaimed as pastureland. A shrub density of 1,000 stems per acre will result in a vegetation mosaic that satisfies the cover requirements of wildlife utilizing the area, while providing a high quality forage resource for livestock and wildlife. Big sagebrush will be established on disturbed pastureland sites with the seeding techniques described previously. Direct seeding of shrubs in the Piceance Basin with a mixture containing various forbs and grasses yielded shrub density figures of 48,580 stems per acre 2.05 -52