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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 Rangelands <br />Cover Type <br />Hydrologic <br />A B <br />C <br />D <br />Condition <br />Herbaceous— mLKture of grass, <br />Poor <br />80 <br />87 <br />93 <br />weeds, and low- growing brush, <br />Fair <br />71 <br />81 <br />89 <br />with brush the minor element <br />Good <br />62 <br />74 <br />85 <br />Oak - aspen — mountain brush <br />Poor <br />66 <br />74 <br />79 <br />mixture of oak brush, aspen, <br />Fair <br />48 <br />57 <br />63 <br />mountain mahogany, bitter brush, <br />Good <br />30 <br />41 <br />48 <br />maple, and other brush <br />Pmyon juniper— pinyon, jumper, <br />Poor <br />75 <br />85 <br />89 <br />or both; grass understory <br />Fair <br />58 <br />73 <br />80 <br />Good <br />41 <br />61 <br />71 <br />Sagebrush with grass understory <br />Poor <br />67 <br />80 <br />85 <br />Fair <br />51 <br />63 <br />70 <br />Good <br />35 <br />47 <br />55 <br />saltbush, greasewood, creosote- <br />Poor <br />63 77 <br />85 <br />88 <br />bush, blackbrush, bursage, palo <br />Fair <br />55 72 <br />81 <br />86 <br />verde, mesquite, and cactus <br />Good <br />49 68 <br />79 <br />84 <br />Notes. Values are for average runoff condition, and 18 = 0.25. <br />Hydrologic Condition: Poor is <30% ground cover (litter, grass, <br />and brush <br />overstory), Fair is 30% to 70% ground <br />cover, Good is >70% <br />ground cover. <br />Curve numbers for Group A have been developed only for desert shrub. <br />Exhibit 7 Page 15 Revision Date: 3/18/13 <br />Revision No.: TR -95 <br />