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Table 8 Curve Numbers Provided in the SEDCAD model (from National Engineering <br />Handbook (NEH-4) (USDA-SCS, 1985), Continued <br />Runoff Curve Numbers for Arid and Semi Arid Ra elands <br />Cover Type Hydrologic A B C D <br /> Condition <br />Herbaceous-mixture of grass, Poor 80 87 93 <br />weeds, and low-growing brush, Fair 71 81 89 <br />with brush the minor element Good 62 74 85 <br />Oak-aspen-mountain brush Poor 66 74 79 <br />mixture of oak brush, aspen, Fair 48 57 63 <br />mountain mahogany, bitter brush, Good 30 41 48 <br />maple, and other brush <br />Piny--juniper--p inyon, juniper, Poor 75 85 89 <br />or both; grass understory Fair 58 73 80 <br /> Good 41 61 71 <br />Sagebrush with grass understory Poor 67 80 85 <br /> Fair 51 63 70 <br /> Good 35 47 55 <br />saltbush, greasewood, creosote- Poor 63 77 85 88 <br />bush, blackbrush, bursage, palo Fair 55 72 81 86 <br />verde, mesquite, and cactus Good 49 68 79 84 <br />Notes Values are for average runoff condition, and la = 0.25. <br />Hydrologic Condition: Poor is <30% ground cover (litter, grass, and bru sh <br />overstory), Fair is 30% to 70% ground cover, Good is >70% ground cover. <br />Curve numbers for Group A have been developed only for desert shrub. <br />Exhibit 7 Page 14 Revision Date: 6/19/09 <br />Revision No.: TR-73