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rates. Because this shearing process may have negatively impacted the shrub survival <br /> rate, mid-slope shrub plantings in 2004 occurred only at locations where this process was <br /> judged to not be a significant factor, particularly at areas with a less steep slope profile. <br /> Review of the relative sediment yield data(Tables 3, 4, 5) indicates that some degree of <br /> success was achieved by the surface stabilization efforts undertaken at Coal Basin. <br /> Quantitative analysis of the data contained in Tables 3, 4 and 5 indicates that nearly a <br /> 50% overall reduction in sediment delivery was achieved as a result of the revegetation <br /> projects undertaken at the outslopes. While we do not view the model as an empirical <br /> evaluation of the sediment yield at Coal Basin, it is apparent from the model that a <br /> significant reduction in relative sediment yield has been achieved over time following <br /> completion of the Non-Point Source project. <br /> While one goal of the project was to minimize sediment generation from the outslopes, <br /> the second goal was to attain a measurable decrease in iron concentration in Coal Creek. <br /> The reduction of sediment delivered from the outslopes should result in decreased iron <br /> loading in Coal and Dutch Creeks. Empirical data of iron loading in Coal Creek is not <br /> available from periods when water was draining from the mine bench outslopes. This is <br /> because the toe of the outslopes are nearly inaccessible during snowmelt runoff. <br /> However, given the relative area of exposed iron bearing strata in Coal Basin as <br /> compared to the relative area of the mine bench outslopes, it is highly unlikely that a <br /> measurable decrease in iron would be measured in Coal Creek at the time water runs off <br /> of the mine bench outslopes. <br /> Summary <br /> Mining related down-slope waste materials at the Coal Basin Mines had been thought to <br /> be significant sources of iron bearing sediment. This sediment had migrated from the <br /> mine bench outslope to Coal Creek, Dutch Creek and their tributaries since they were <br /> constructed in the 1950's and 1960's. <br /> Following closure of the mine in the early 1990's the Division of Reclamation, Mining <br /> and Safety began to reclaim the mine. Stabilization of the mine bench outslopes was <br /> identified as a reclamation priority due to the perceived impact of these facilities on <br /> nearby water resources. <br /> Minimization of sediment generation using vegetative processes was identified as the <br /> most appropriate method of stabilizing the slopes. To this end, revegetation of the slopes <br /> was begun in 1999. Hand crews, supplemented by a helicopter scarified and planted <br /> approximately twenty four acres of steep slopes. Trees and shrubs supplemented the <br /> initial planting in 2000. Due primarily to drought conditions, the 1999 revegetation effort <br /> was not as successful as had been anticipated. <br /> A second revegetation project was initiated in 2004. This project was similar to the 1999 <br /> project, but was modified by identifying the shortcomings of the initial effort, and <br /> 15 <br />