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Evaluation of Potential Subsidence Impacts of Longwall Mining in the Spruce Stomp Lease Area <br />to Aquatic Life and Water Supply <br />At the request of Bowie, WWE conducted detailed habitat surveys at five reaches within the <br />Spruce Stomp Lease Area. These surveys were conducted using the methodology described by <br />Winters and Gallagher (Winters, 1997) and adopted by the Pike and San Isabel National Forests. <br />Surveyed reach lengths ranged from approximately 500 feet to 1,200 feet and included <br />measurements of habitat and cover type, area, volume, and substrate. The results of these <br />surveys are summarized on Figure 7 and are available upon request. The surveyed reaches had <br />riffle habitats composing 59 -85 percent of the overall channel area. Pools composed between <br />13 -30 percent of the overall channel area. Glides were largely absent (not unexpected for a high <br />gradient headwater creek) and composed between 0 -11 percent of the overall channel area. <br />Based on observations made during other studies of fish habitat in similarly high gradient <br />streams, riffle - associated pocket waters may contain abundant microhabitat that is used by <br />cutthroat trout (Young, 2008) <br />Willows grow densely along and within the creek's ordinary high -water mark. This growth, in <br />combination with large cottonwoods and firs, contributes significant large and small woody <br />debris and helps support resident heterotrophs. Further, this dense riparian vegetation provides <br />significant habitat modification when trees fall within or across the channel and modify flow and <br />sediment transport. <br />An analysis of existing creek sediment transport identified that under high flows, the structure <br />velocity produces sufficient shear stress to move much of the sediment located within the <br />channel (see Appendix 2). Larger boulders (> 1 meter diameter) resist movement during normal <br />high flows and as a result, many of the observed riffle and pool areas are formed by these <br />features. <br />4.2.2 Water Quality (Designated Uses, Standards and Baseline Quality) <br />In the Spruce Stomp Lease Area, West Fork Terror Creek is identified as Segment 4 and <br />Segment 5 of the North Fork Basin by the Colorado Water Quality Control Commission <br />(WQCC). Segment 4 includes those portions of West Fork Terror Creek that are within U.S. <br />National Forest property. Segment 5 includes the reaches of West Fork Terror Creek that are <br />downstream of the U.S. National Forest Service boundary. The WQCC has identified designated <br />121 - 014.000 Wright Water Engineers, Inc. Page 9 <br />January 2013 <br />