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Tablet-5.6 SCS Runoff Curve Numbers <br />LAND USE DESCRIPTION <br />CURVE NUMBERS BY <br />HYDROLOGIC SOIL GROUP <br />A <br />B C <br />D <br />Cultivated Land <br />winter condition <br />86 <br />91 94 <br />95 <br />Mountain open area <br />low growing brush & grasslands <br />74 <br />82 89 <br />92 <br />Meadow or pasture <br />65 <br />78 85 <br />89 <br />Wood or forest land <br />undisturbed <br />42 <br />64 76 <br />81 <br />young second growth or brush <br />55 <br />72 1 <br />86 <br />Orchard <br />with cover crop <br />81 <br />88 92 <br />94 <br />Open spaces (lawns, parks, <br />golf courses, landscaping, etc.) <br />Good condition <br />grass cover on >75% of area <br />68 <br />. 80 <br />90 <br />Fair condition <br />grass cover on 50-75% of area <br />77 <br />85 90 <br />92 <br />Gravel roads and parking lots <br />76 <br />85 89 <br />91 <br />Dirt roads and parking lots <br />72 <br />82 87 <br />89 <br />Impervious surfaces <br />pavement, roofs, etc. <br />98 <br />98 8 . <br />98 <br />Open water bodies <br />lakes, wetlands, ponds, etc. <br />100 <br />100 0 <br />100 <br />Single family residential (1) <br />Dwelling Unit/Gross Acre <br />% Impervious <br />1.0 <br />15 <br />Separate curve <br />1.5 <br />20 <br />numbers must <br />2.0 <br />25 <br />be selected for <br />2•5 <br />30 <br />pervious and <br />3.0 <br />34 <br />impervious <br />3.5 <br />38 <br />portions of the <br />4.0 <br />42 <br />site or basin <br />4.5 <br />46 <br />5.0 <br />48 <br />5.5 <br />50 <br />6.0 <br />52 <br />6.5 <br />54 <br />7.0 <br />56 <br />PRD's, multi -family, <br />commercial, industrial <br />(1) The % impervious values assume that roof and driveway runoff is directed into the street/storm system <br />1-5-33 <br />