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STOAMW)1TEA M)1N.\GEHENT MANUAL FOR THE PUGET SOUND BASIN <br />Teble III-1.3 SCS Waotarn Wn�hlnqton Runoff Curva Numbar• <br />(Publi�h�d by 8CS in 1982) Runoff curv� numbars for selected eqricultural, <br />au6ur6en �nd urhwn <br />l�nd u�a for T lA reinfell di�trlbutlon, 24-hour atorm duratlon. <br />LAND USE D6SCRIPTION CURVE NUMBERS BY <br />HYDROLOOIC SOIL CROUP <br />A B C D <br />Cultivet�d land 1 t winter condition B6 91 94 95 <br />Mountain o n•rosei low rowln brurh 6 rsaelenda 74 B2 B9 92 <br />Meadow or ■oturai 65 78 BS 89 <br />ilood or for�et lend� undiaturbad 42 64 76 81 <br />Nood ot :ora�t lendi young eecond growth or brueh 55 72 81 86 <br />Orchsrd� with cover cro 81 BB 92 94 <br />Open epecee, lewne, perke, golf coureee, cemeteriee, <br />landacsping. <br />Goad conditionc graee cover on z75♦ of the 68 BO B6 90 <br />erae <br />Fair conditloni grese cover on 50-75� of 77 85 90 92 <br />the aree <br />Grevrl roeda 6 parking lota: 76 85 89 91 <br />Dirt roeds 6 erkln lote: 72 B2 87 B9 <br />Impervioue eurfecee, pavement, roofe etc. 98 98 78 98 <br />O n weter bodlee: lekee, wetlenda, ondo etc. 100 300 100 100 <br />Sinqle femily reeidentisl(2): <br />Owelllnq Unit/Croee Acre •Impervloue(3) Seperatu curva number <br />1.0 DU/6A 15 ehell be selected for <br />1.5 DU/OA 20 pervioue i lmpervlous <br />2.0 DU/GA 25 portlone of the eite <br />2.5 DU/OA 30 or beein <br />3.0 DU/CA 3q <br />3.5 DU/CA 3B <br />4.0 DU/GA 42 <br />4._' DU/GA 46 <br />5.0 DU/GA 48 <br />5.5 DU/,A 50 <br />6.0 DU/CA 52 <br />6.5 DU/CA 5q <br />7.0 DU/CA 56 <br />PUD's, condoe, apertmenta, limpervioue <br />commercisl buelneeaee i muat be <br />lndu�trl�l •reac computed <br />(1) For • mora datalled deeorlption of egricultural lend u�e curve numbere rafar <br />to National Enqineering Hendbook, 6ec. 4, Nydrology, Chepter 9, Auqust 1972. <br />(2) Aaeumea roof end driveway runoff la directed into etraet/etorm systam. ,�-� <br />(3) Tha remeining pervioue areae (lawn) sre coneidered to be in good STO�%� <br />condltlo� for theee curve numbere. ���DtD�b <br />III-1- 2 F68(tU11RY, �� <br />y�7 <br />