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Table 1-5.6 SCS Runoff Curve Numbers <br />LAND USE DESCRIPTION CURVE N[II�ffiERS BY <br />HYDROLOGIC SOII. GROUP <br />A B C D <br />Cultivated Land winter condition 86 91 94 9� <br />Mountain open area low growing brush & grasslands 74 82 89 92 <br />Meadow or pasiure 6� 78 8� 89 <br />Wood or forest land undisrurbed 42 64 �s'rt r81 <br />young second growth or brush 55 72 81 �6 <br />Orchazd with cover crop 81 88 92 94 <br />Open spaces (lawns, pazks, . <br />�olf counes, landscapin„ etc.) ��/. <br />Good conditio� grass cover on >75% of azea 68 80 � 90 <br />Fair condition grass cover on 50-75% of area 77 85 90 � 92 <br />Gravel roads and pazking lou 76 8� 89 91 <br />DiR roads and pazking lou 72 82 87 89 <br />Impervious surfaces pavement, roofs, etc. 98 98 9 98 <br />Open water bodies lakes, wetlands, ponds, etc. 100 100 100 100 <br />Single familyresidential (1) <br />Dwelling UnidGross Acre % Impervious <br />1.0 15 Separate curve <br />I.5 ZO numbers must <br />2.0 25 be selected for <br />2.5 30 pervious and <br />3.0 3�t impervious <br />3.5 38 �ortions of the <br />4.0 42 site nr basin <br />4.5 46 <br />5.0 48 <br />5.� 50 <br />6.0 52 <br />6.5 54 <br />7.0 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 />� <br />1-5-33 �g <br />