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JD -7 Mine Drainage Design Plan 32 <br />Figure 13. Photos Showing Natural Streambed and Scour in Major Sub -Basin B2 <br />Suftin and Wohl (2012) developed a geomorphic classification for ephemeral streams in the and <br />southwestern United States based on the degree of confinement and the composition of confining material. <br />Five stream types were identified: <br />1) bedrock channels entirely confined by exposed bedrock and void of persistent alluvium; <br />2) bedrock with alluvium channels at least partially confined by bedrock but containing enough <br />alluvium to create bedforms that persist through time; <br />3) incised alluvium channels bound only by unconsolidated alluvial material into which they are <br />incised; <br />4) braided washes that exhibit multi- thread, braided characteristics regardless of the degree and <br />composition of confining material; and <br />5) piedmont headwater 0 -2nd order streams confined only by unconsolidated alluvium and which <br />initiate as secondary channels on piedmont surfaces. <br />Using this classification system, the channels at and near the JD -7 Mine are Type 1 (natural channels on the <br />escarpment), Type 2 (natural channels near the toe of the escarpment), and Type 4 (natural channels on the <br />valley floor). <br />The hydraulic parameters, including length, width, slope, and Manning's n, for the modeled reaches at the <br />JD -7 Mine are summarized in Table 13. The reach locations are shown in Figure 12. <br />4149A.140207 Whetstone Associates <br />