SW1210902_Plansheet C2.2 - SCM Detail_20220215

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HW-2
I SW 36" INV=2049.60
ti
,N Fw 0�� 44 LF OF 24" HDPE
DA 3 N-12 WT ST 0.50%
5�p _
JB 1.1
RIM=2059.53
ISW 18" INV=2049.26I
S 10" INV=2057.00 c
UA 41 E 24" INV=2049.22 -N
6 LF OF 10" HDPE /
I N N-12 T STr ® 2.00%
I ,
uuuuuuuuuu TRENCH IDRAIN SEE /
I PROPOSED IMPACTS I , NCDOT DETAIL 840.30
STREAM 1 ON SHEET C2.4.
88.4 LF 0.006 AC
SAND FILTER 2060
LF OF
D A = 6.2 7 AC ' 78 LF OF 36" HDPE N8 12 WT ST8'0HDPE 050%
I N-12 WT ST 0 2.15% 20
5 IIIIIIII'III
l'
I BENCHED FILL SLOPE.
2:1 MAX. SEED AND
DA 10 HW 1 1
I STABILIZE AS SPECIFIED.I I
� I
-
INE 36" INV=2051.28 I I I 1 11 I
EXISTING BYPASS
ISWALE, TO REMAIN.
0
FW �
FES-2
SW 24" INV=2052.00i
/12' WIDTH RIP -RAP EMERGENCY
SPILLWAY. D50=8". INSTALL TO 16"
DEPTH OVER MIRAFI 140N EC FABRIC.
64 LF OF 24" HDPE
-12WTST® 2.00%
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2070.00 o I
FG OCS-2.1
RIM=2062.50
2070 SE 4" INV=2056.50
NE 24" INV I0 3.28
SANDFILTER. SEE DETAIL
BELOW 1,823 SF. MIN.
/ 10' MIN. WIDTH ACCESS °eoz
/ MAINTENANCE BERM.
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SW 24"
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• • _� C' •
206�.4� / I \ / I 2064.57
272 LF OF 18" HDPEJ_ _z 2064.07
2:1 SIDE SLOPES. STABILIZE_z
W/ SOD, CONTINUOUS AROUND CI-2.3
- SIDES & TOP OF BERM. RIM=2064.07
- � NW 18" INV=2059.57 /
_SW 15" INV=2059.59____�
= NE 24" INV=2059.55-
DA _ I / ENLARGED VIEW: TRUCK ENTRANCE ENLARGED VIEW: SAND FILTER
I / / SCALE: 1 "=20' SCALE: 1 "=20'
6.J 1 U I 1 V I E VF1 0 E' I
60' R/W AND VARIABLE WIDTH R/W
DRAINAGE AREA MAP
SCALE: 1 "=80'
DA 7
DITCH CALCULATIONS
DITCH
DIMENSIONS
Q10 (CFS)
V (FT/S)
DEPTH (FT)
STABILIZATION
SHAPE: TRAPEZOIDAL
DITCH-1A
BOTTOM WIDTH=2'
2.67
1.51
0.37
SOD
MIN. VERT. DEPTH=1.0'
SHAPE: TRAPEZOIDAL
DITCH-1 B
BOTTOM WIDTH=2'
6.33
2.30
0.68
SOD
MIN. VERT. DEPTH=2.0'
SHAPE: TRAPEZOIDAL
DITCH-1 C
BOTTOM WIDTH=2'
5.90
2.34
0.68
SOD
MIN. VERT. DEPTH=3'
SHAPE: TRAPEZOIDAL
DITCH-2
BOTTOM WIDTH=2'
24.76
5.92
1.03
SOD
MIN. VERT. DEPTH=3
SHAPE: TRIANGULAR
EXISTING DIVERSION DITCH
MIN. VERT. DEPTH=1.2'
24.76
7.21
1.07
N/A
AVE. SIDE SLOPE=3:1
DRAINAGE AREA TABLE
DA
RECIEVING STORM
SYSTEM
ON -SITE
AREA (AC)
OFF -SITE
AREA (AC)
TOTAL
AREA (AC)
CN
ToC (MIN)
Q10 (CFS)
Q25 (CFS)
DA-1
TRENCH DRAIN
0.13
0.00
0.13
98.00
5.00
0.90
1.07
DA-2
CI-2.4
0.99
0.00
0.99
96.00
5.00
7.35
8.70
DA-3
CI-2.3
0.51
0.00
0.51
92.00
5.00
3.61
4.32
DA-4
DITCH-1 C
1.77
0.00
1.77
80.00
19.10
5.90
7.49
DA-5
DITCH-1 B
1.59
0.00
1.59
82.00
14.70
6.33
7.99
DA-6
D ITCH-1 A
0.47
0.00
0.47
87.00
7.10
2.67
3.27
DA-7
EXIST. 18" CMP
0.00
25.20
25.20
62.00
33.90
26.41
38.85
DA-8
EXISTING DRAINAGE DITCH
0.67
25.20
25.87
62.00
33.90
24.76
36.90
DA-9
EXISTING STREAM
0.20
26.50
26.70
61.00
37.90
24.52
36.57
Know what's below.
Call before you dig.
;� No, 14051z, w
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STUB 4" SCH. 40 PVC UNDERDRAIN
INTO OUTLET CONTROL STRUCTURE.
4" STUB SERVES AS CONTROL
ORIFICE. INV. ELEV = 2056.50
COMPACTED SUBGRADE
SAND FILTER DETAIL
SCALE: NOT TO SCALE
- LINE BOTTOM AND SIDES OF SAND
FILTER CHAMBER AND RIP -RAP
FOREBAY W/ NON -WOVEN
SOIL SEPARATING FABRIC.
6" DEPTH J" WASHED STONE W/ 4"
SLOTTED PVC UNDER -DRAIN CENTERED
W/N STONE BED. SEE PLAN. PROVIDE TEE
SECTION AND CLEANOUT STANDPIPES AT
THE END OF EACH RUN.
QUALITY CONTROL CALCS.
RV = 0.05 + 0.9 X IA
WHERE RV = RUNOFF COEFFICIENT
(STORM RUNOFF (IN) /
STORM RAINFALL (IN)), UNITLESS
IA = IMPERVIOUS FRACTION
(IMPERVIOUS PORTION OF DRAINAGE
AREA (AC) / DRAINAGE AREA (AC))
DRAINAGE AREA AT BUILD -OUT:
RV=0.05+0.9 (5.13/6.27)
RV = 0.786
AND WQV 3630 X RD X RV X A
WHERE WQV = FILTRATION VOLUME (CUBIC FEET)
RD = DESIGN STORM RAINFALL DEPTH (IN) 1.0
FOR
MILLS RIVER
A = WATERSHED AREA (AC)
DRAINAGE AREA: WQV = 3630 X 1.00 X 0.786 X 6.27
WQV = 17.889 CF
ADJUSTMENT FOR SAND FILTER = WQV X 0.75 = 13.417
CF
SURFACE AREA REQUIREMENT AT 4' AVG. DEPTH = 3,354
SF.
PROPOSED = 3,646 SF. (1,823 FOREBAY & 1,823 SAND
FILTER)
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JOB NO.
NK2001 .01 A
SHEET cD
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C2.2
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