2014-11-21_PERMIT FILE - C1996084 (23)

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Ru[r 2: Prmtirs drainages are included in the Purgatoire River drainage. The watersheds contain both forested and open slopes. • • Drainage basins identified in the study area range from 0.9 miz to 403.7 miZ. Drainage basins within the permit boundary range from 0.9 miz to 3.2 miZ for Jeff Canyon and Cow Canyon, respectively. Within the study area, Cow Canyon and Lorencito Canyon are the principal drainages. Although several small side drainages exist, Cow Canyon is a fully enclosed basin, and receives no waters from outside the basin or from contributing drainages. Lorencito Canyon is the principal drainage in the permit area and receives waters from Jeff, Chimney, Puettecito, Little Pine, Bonita, Alamosa, and Little Alamosa Canyons. All of these drainages eventually empty into the Purgatoire River. The lower reaches of Cow Canyon and all of Lorencito can be described as mature channels formed in alluvial valleys. The remaining drainages can be described as generally young channels, characterized by steep sides, with "V" shaped valleys with steep gradients (Lect, et al. 1982). Characteristics of the major drainages connected to and within the project area are detailed in Table 2.04.7-1. TABLE 2.04.7-1 LORENCITO CANYON MINE DRAINAGE CHARACTERISTICS Drainage Flow Regime' Watershed Length Channel Slope (acres/ miz) (feet/mi) within Permit Area (%) Lorencito I, P 44,757/ 141,863/ I.55 69.9 26.9 Cow 1 2,023/ 19,(98/ 4.37 3.2 3.65 Chimney E, 1 1,427/ 15,127/ 4.69 2.2 2.8 Jeff E,1 612/ 10,375/ 4.79 0.9 1.9 Puertecito E,1 1,154/ 12,134/ 4.85 1.8 2.2 Little Pine E, I 1,371/ 13,628/ 4.25 2.1 2.5 Bonita E, I 2,062/ 12,243/ 4.46 3.2 2.3 Alamosa I 10,156/ 48,292/ 2.32 15.9 9.1 Little Alamosa E 1,528/ 12,224/ 4.21 2.4 2.3 S. Fork of the P 65,397/ 94,025/ 1.47 Purgatoire 102.2 17.8 Purgatoire P 258,392/ 150,254/ 0.57 403.7 28.4 (P)erennial, (i)ntermittent, (E)phemeral PERMR.1]6\Desmbu I0, 1996 2.04-26