Laserfiche WebLink
regraded roads were then severely ripped using a dozer, followed by fertilizer, seed and <br /> mulch. <br /> The roads weathered the spring runoff fairly well. Road C, which provides access from <br /> Dutch Creek to Mine 4, suffered virtually no erosion damage. The dips and low water <br /> crossings were spaced appropriately, and were adequately sized to accommodate the <br /> snow melt runoff. Dip spacing was very tight at the upper portion of the road as it <br /> approaches Mine 4. The close spacing was necessary as the road switchbacks steeply <br /> in this area, thus concentrating drainage at the lower portions of the switchbacks. This <br /> tight spacing worked extremely well in effectively handling the volume of water crossing <br /> the road surfaces. <br /> Road D accesses Mines 1 and 2 from the bottom of Road C near Dutch Creek, <br /> approximately one mile west of the Lamphouse. The upper portion of Road D, <br /> approximately one mile in length, did not suffer any erosion damage. The middle to <br /> lower portions of the road suffered minor erosion damage, primarily as a result of <br /> constructing slightly undersized drainage dips in 2000. It was observed that the dips <br /> had sufficient capacity to convey the volume of flow, but the base of some of the dips <br /> was not wide enough to accommodate the velocity of the flow. The narrow base of <br /> these dips tended to concentrate energy, allowing the flows to slightly incise themselves <br /> at these locations. In two instances, it was observed that additional drainage dips were <br /> needed, as a result of unforeseen water contributions from upslope areas. <br /> Road B is an approximately one mile long road segment which provides access from <br /> the Lamphouse to the intersection of Roads C and D. Road B suffered the most <br /> damage during the spring runoff. Although minor in extent, erosion was more <br /> pronounced on this road. This occurred because the road is situated at the base of a <br /> south facing slope at about the elevation of Dutch Creek. As a result, it has a very <br /> significant contributing area. Further, the cut slope of the road is host to many seasonal <br /> springs and seeps. In some areas, the density of drainage dips was insufficient to <br /> accommodate the number of seasonal cross flow sources which develop during the <br /> spring. In another area, the dips were undersized to handle the velocity of the flow. <br /> This resulted in down cutting of the base of the drains, and subsequent deposition of <br /> sediment below the dip outlets. <br /> Approximately 18,000 trees were planted in Coal Basin in 2000. All but about 1,500 <br /> were planted by a contractor at previously reclaimed areas. The remaining trees were <br /> planted by middle school students on Forest System property in the vicinity of the Dutch <br /> Creek Diversion. Casual observation indicates that overall, about fifty percent of the <br /> trees survived. The survival rate appears to be higher in shaded or sheltered areas <br /> than in more exposed areas. Two hundred trees were planted on the lower third of the <br /> Mine 1 Mine Bench Outslope. Of these two hundred trees, half were protected with tree <br /> shelters, and the other half were planted unprotected. The overall survival rate of these <br /> trees was also fifty percent. The survivors were almost evenly split between sheltered <br /> and unsheltered trees. However, the trees protected by shelters appeared to be <br /> healthier and more vigorous than the unprotected trees. <br /> 3 <br />