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HomeMy WebLinkAboutMiscellaneous - 980 OSGOOD STREET 1/6/1986 ESSEX COUNTY, MASSACHUSETTS, NORTHE 18!.700000 FEET PbC PaB "'�dd fix° s Crt1B" i• � J �@ N PaB e 3 aA � � s�, ,3� " r �x t� PaC WnA WnB UD 1 p� PaC P� pae .5 01 L 5 Wek t'T�, r'�t,�� •� .3 #�� ';�� �, �,. a � � A ^ a Ire SOIL eO�scRVATIo0 5ERv�CE i •'1�t.1 �� UQ K y 'f Yea P84 � � F T M�' WnA� r•r a � �°.-� � .z� � �� �„ PaB �tcE �'>», � �, A � fias x ape �` Epp ."., •'r""� ` '$ �_a '� WnB De r PaB N • t, ,gym n4 - 1 � Ur PaD. � ' eA WrB ��a ag , s dCUj � �. = Pae r Jx h • ci' rr 1� s , n .x uN o 't frf WrB� -Als a f� r .. S ; � �� _ 'mot � '•`' � � .�. Sr , a " 5 j"y ll� r :: GOO IM a Table '2-2c.—Runoff curve numbers f or other agricultural lands' Curve numbers for Cover description hydrologic soil group— Hydrologic Cover type condition A B C D land. or range—continuous Poor 68 79 86 89 Pasture,grass 49 69 79 84 forage for grazing. Good 39 61 74 80 Nleadow—continuous grass, protected from — 30 58 71 78 grazing and generally mowed for hay. Brush—brush-weed-grass mixture with brush Poor 48 67 it 83 the major element.' Fair 35 56 70 77 Good 430 48 65 i3 Woods—grass combination(orchard Poor 57 73 82 86 or tree farm).s r air 43 65 76 82 Good 32 58 72 19 Woods.e Poor 45 66 77 83 Fay 36 60 73 79 IN Good 430 55 77 Farmsteads—buildings,lanes, driveways, — 59 74 82 86 19 and surrounding lots. 'Average runoff condition,and 1„ -O.LS. s Pour: <5o% ground cover or heavily grazed with no mulch. Farr: 50 to trle ground cover an([not heavily grazed. G(xxl: >75% ground cover and lightly or only occasionally grazed. <5K ground cover. Fair: 50 to 75%gr6und cover. (nxxi: >75%ground cover. 'Actual curve number is less than 30:use CN =30 for runoff computations. TNb shown were computed for a reus with 50% waxxls and 50%grassy(pasture)Grover. Other combinations of conditions may be computed from the CN's for%eoo(Is and pasture. al'rxx•: Forest litter,small trees,and brush are destroyed by heavy grazing or regular burning. Fair: Woods are grazed but not burned.and some forest litter covers the:oil. (kxx1: Wools are protected from grazing,and litter and brush adequately cover the:oil. (210-VI-TR-55, Second Ed., June 1986) 2-7 Table 2.2a.—Runoff curve numbers for urban areas3 Curve numbers for Cover description hydrologic soil group— Average percent Cover type and hydrologic condition impervious areas A B C D Fully developed urban areas (vegetation established) Open space(lawns, parks,golf courses, cemeteries, etc.P: Poor condition (grass cover < 50 . .............. 68 79 86 89 Fair condition (grass cover 50% to 75'70)........... 49 69 79 84 Good condition (grass cover > 75%) .............. 39 61 74 80 Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way). ......................... 98 98 G> 98 Streets and roads: Paved>curbs and storm sewers(excluding right-of-way).................................. 98 98 98 98 Paved; open ditches(including right-of-way) ....... 83 89 92 93 Gravel (including right-of-way) ................... 76 85 89 91 Dirt(including right-of-way) ..................... 72 82 87 89 Western desert urban areas: Natural desert landscaping(pervious areas only)~... 63 77 85 88 Artificial desert landscaping(impervious weed barrier, desert shrub with 1- to 2-inch sand or gravel mulch and basin borders). .............. 96 96 96 96 Urban districts: Commercial and business.......................... 85 89 92 94 95 Industrial........................................ 72 81 88 91 93 Residential districts by average lot size: ` 1/8 acre or less(town houses)...................... 65 77 85 90 92 V4 acre ......................................... 38 61 75 83 87 1/3 acre ........ ....................1 a'! MAP 30 57 72 81 86 1/2 acre .......................................... 25 54 70 80 85 1 acre........................................... 20 51 68 79 84 2 acres .......................................... 12 ` 46 65 77 82 Developing urban areas Newly graded areas(pervious areas only, no vegetation)3 77 86 91 94 ' Idle lands (CN's are determined using cover types similar to those in table 2.20. l 'Average runoff condition,and I, -0.2S. rfhe average percent impervious area shown was used to develop the composite CN's.Other assumptions are as follow: impervious areas are directly connected to the drainage system,impervious areas have a CN of 98,and pervious areas are considered equivalent to open space in Rood hydrologic condition. CN's for other combinations of conditions may be computed using figure 243 or 24. 3CN'+shown are equivalent to those of pasture. Composite CN's may be computed for other combinations of open space cover type. 'Composite CN's for natural desert landscaping should be computed using figures 2.3 or 2.4 based on the impervious area percentage(CN 98)and the pervious area CN.The pervious area CN's are assumed equivalent to desert shrub in poor hydrologic condition. 'Composite CN'-;to use for the design of temporary measures during grading and construction should be computed using figure 2-3 or:!4. based on the degree of development(impervious area percentage)and the CN's for the newly graded pervious areas. (210-VI-TR-55, Second Ed., June 1986) 2.5