2013-06-13_REVISION - M1977305

• Permit No: M1977305
• IBM Index Class Name: REVISION
• Doc Date: 6/13/2013
• Doc Name: AM1 AR4 RESPONSE
• From: OPERATOR
• To: DRMS
• Type & Sequence: AM1
• Email Name: DMC
• Email Name: TC1
• Media Type: D
• Archive: No

_ 2 -5
Seas —( R, se,
_ Table 2 -2. -- Runoff curve numbers for selected agricultural, suburban, and
urban land case. (Antecedent moisture condition II, and Ia = 0.25)
I
T
--r
iI For a more detailed description of agricultural land use curve numbers refer to
Nation" ftaineft-ing Haadbook, section 4, $►�1o8T. Chapter 9, Aug. 1972.
Good cover is protected from grazing and litter and brush cover soil.
J Curve numbers are computed assuming the runoff from the house and drivevq
is directed towards the street with a minimum of zoo water directed to lawns
where additional infiltration could occur.
=/ The remaining pervious areas (lean) are considered to be in good pasture condition
for these ourve numbers.
In some warmer climates of the country a curve number of 93 mrgr be used.
HYDROLOGIC soli. GROUP
LAU iF
D SE DESCRIPTION
A
s
c
n
Cultivated landl /: without conservation treatment
T2
51
88
91
: with conservation treatment
62
71
78
81
Pasture or range land: poor condition
68
79
86
A9
good condition
39
61
7h
80
Meadow. good condition
30
58
Ti
78
Wood or Porest lend: thin otaad, poor cover, no mulch
45
66
TT
83
good covea+-Y
25
55
TO
77
Open Spaces. -lvnw. parks, golf courses, cemeteries, etc.
good condition-grass cover on TO or more of the area
49
1161
Th
80
fair condition: grass carver on 50% to T5% of the area
49
69
79
8h
commercial and busimme areas (85% impervious)
89
92
94
95
Industrial districts (12% impervious).
81
88
91
93
Residential:s/
Average lot size Average % Impervious)/
1/8 acre or l.ss 65
77
85
90
92
1/4 acre 38
61
T5
83
87
1/3 acre 30
5T
T2
01
86
112 acre 25
54
70
80
85
1 ae" 20
51
68
79
84
Paved parking lots, roofs, drivws" . etas/
98
98
96
98
Streets and roads:
paved vith carte and steam several/
98
98
98
98
gravel
76
85
89
91
dirt
72
82
87
89
iI For a more detailed description of agricultural land use curve numbers refer to
Nation" ftaineft-ing Haadbook, section 4, $►�1o8T. Chapter 9, Aug. 1972.
Good cover is protected from grazing and litter and brush cover soil.
J Curve numbers are computed assuming the runoff from the house and drivevq
is directed towards the street with a minimum of zoo water directed to lawns
where additional infiltration could occur.
=/ The remaining pervious areas (lean) are considered to be in good pasture condition
for these ourve numbers.
In some warmer climates of the country a curve number of 93 mrgr be used.