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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 neazly 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 aze neazly 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 eazly 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 scazified 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 />