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• to The schematic flow diagram of the Magpie Creek watershed for present-mining cronditions is shown in Figure 1. Individual subwatersheds within the G.E.C. permit boundary for present-mining conditions are shown in Figure 2. For present-mining conditions, the Tipple Area is represented by one subwatershed unit and one reservoir unit; for post-mining conditions, it is represented by one subvatershed unit. The Newlin Creek watershed was modeled assuming no dif- ' ference between the present- and post-mining conditions. The present-mining ' condition assumes that the Newlin Creek stream channel at the "Prospecting Pit" area is reclaimed so that the existing culvert at the watershed outlet rnuld be analyzed. A schematic flow diagram of the Newlin Creek watershed is C presented in Figure 3. In the Preliminary Data Base Report, the watershed segmentation of the Magpie Creek drainage for post-mining conditions assumed that the channels would r ba restored to their original bed slopes, cross-sectional shapes, and alignment. • This condition also assumed that the Dorchester Mine area had been reclaimed and the Magpie Creek diversion within Dorchester's permit boundary had been restored to its natural conditions. State officials stated that the Magpie Creek diversion channel within Dorchester's permit boundary was a permanent diversion, and therefore, would not need to be restored to its original char- . nel shape, slope, and alignment. In addition, the area within G.E.C. Minerals, inc. permit boundary will be reclaimed before the Dorechestez Nine area. Due to these reasons, the watershed segmentation of the Magpie Creek drainage for post-mining conditions had to be changed to reflect this situation. Figure 4 is a schematic flow diagram of the Magpie Creek drainage reoresentinq these changes. Table 3 presents the watershed geometry for all units which have changed in the Magpie Creek drainage for post-mining conditions. 2.5 Typographical Corrections for Preliminary Data Hase Report In the report entitled "Preliminary Data Base for Application of MULTSED Program, G.E.C. Minerals, Inc., Florence, Colorado," there are a few corrections that need to be made. Following is a list of corrections. 1. Page 15 - three existing sediment pond structures should read four • existing pond structures. 2. Page 20 - The values for Sw-lOL and Sw-lOR should be interchanged. 3. Page 25 - Sediment Pond "D" should read Sediment Pond "T". ' 4.' Page 28 - CH-17; 4.002 should be 4.022.