SW6210204_Plan (Prop. DA)_20210422

UGP
UGP UGP
TTTT
T
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UGP UGP UGP
UGP UGP UGP
GSANSANSANSANSAN
SANSAN
SAN
UGTUGTUGTUGTUGT
UGT
UGP
UGP
UGP UGTUGTUGT
UGT
UGT
G
GG
W
W UGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTUGTTTTT
S
TTT
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GGGUGP
UGPUGPUGPUGPUGPUGPUGP
UGP UGP UGP
UGP
UGP
UGP UGP UGP
UGP UGP
UGP
UGP
UGP UGP
UGP UGP
UGP UGP
G
G G G G G G
G G G G G G
GGGGGGUCATV
UCATV
UCATV UCATV UCATV UCATV
UCAT
V
UCATV UCATV UCATV
UCATV
UCATV UCATV UCATV UCATV UCATV UCATV
UC
A
T
V
UCATV UCATV
UGT UGT UGT UGT
UCATVUCATVUCATVUCATVUGPUGPT270 270265
270270
OHPOHPOHPOHPOHPOHPWWWWWWWWWWWWWWOHP
OHP
OH
P
OHPOHPOHPOHPOHPOHPOHPUGP UGP
UGP
XXXX
XX2
6
5265270265265265 UCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVUCATVU
C
A
T
V
UCATV
UCATV
UCATVUCATVUCATVUCATVCONSTRUCTION LIMITS
CONSTRUCTION LIMITS
CONSTRUCTION LIMITSCONSTRUCTION LIMITSCONSTRUCTIONLIMITSCONSTRUCTIONLIMITSCONSTRUCTIONLIMITSS1°14'17"W329.72'S1°47'43"E50.00'S9°41'43"E29.30'S86°02'17"W
496.13'N11°40'43"W411.20'N86°02'17"E
580.19'266267268269
272
272 270271272273273269
269
26526126
1
262
26
2 263264 2662
6
7
267
267267267
2
6
7
2682692
6
0 2612
6
2 26126226326226
3
2
6
5
264
269
267268
26
6
266267
2682
6
4
26
4
263262
2682672682
6
7
263
262
261 268267268266267263262
263
264266267268269
269 267
269
268268
269268267267268269
26926726626
4266 268
269
267
267
267
267268
267267
2
6
6
266
26
7
264262
261264 268269
2672682
6
7 268268
SHWT BORING 1
ELEV.: 260.20
SHWT
BORING 2
ELEV.: 260.00
SHWT BORING 3
ELEV.: 259.50
SHWT BORING 4
ELEV.: 261.33
SHWT BORING 5
ELEV.: 261.50
SHWT BORING 6
ELEV.: 262.50
XXXXXX
X
X
X
X
XXXXX XX24" RCP
24" HDPE
24" HDPE6" HDPE18" HDPE18" RCP 10" HDPE10" HDPERDRDRD
RD
RD
8" HDPE
18" RCP6" HDPE
8" HDPE
8" HDPE15" HDPE
2
6
8
26
8
2
6
7
267
267
26726726626626
7
26
8
26
9
2
7
0
269
268
267
270 269
26
7
267
267
268268 268267265
262 263265263267 268 268268267267
24" RCP18" RCP18" RCP24"RCP
HP
268.00
10" HDPE12" HDPEHP
268.00
HP
268.50
RD
RDRDRD15" HDPE
30"
RCP
18" HDPE
18" HDPE24"
RCP
D
D
D
D
DD
D
12" HDPE 6" HDPE10" HDPE
10" HDPE
HP
268.00
8' X 11' FILTER
UNIT (SEE
SHEET C5.6)
SUBSURFACE
DETENTION
ASSEMBLY
(SEE SHEET C5.6)
ANALYSIS POINT A
ANALYSIS
POINT B
A2
A1
B
B
A2
SUBSURFACE
DETENTION
ASSEMBLY
(SEE SHEET C5.6)
JOB NO.
SHEET NO.
SCALE
DESIGNED BY
CHECKED BYDATEDRAWN BY
DATEREVISION DESCRIPTIONYOUR VISION ACHIEVED THROUGH OURS.5410 Trinity Road, Suite 102 | Raleigh, NC 27607TEL [phone] FAX [phone] www.timmons.comTHIS DRAWING PREPARED AT THERALEIGH OFFICEN O R T H C A R O L I N
AP R O F E S S I O N A
LE N G I N E E R
0 3 3 6 1 2N O R T H C A R O L I N
AP R O F E S S I O N A
LE N G I N E E RN O R T H C A R O L I N
AP R O F E S S I O N A
LE N G I N E E RN O R T H C A R O L I N
AP R O F E S S I O N A
LE N G I N E E R
S E A LN O R T H C A R O L I N
AP R O F E S S I O N A
LE N G I N E E RN O R T H C A R O L I N
AP R O F E S S I O N A
LE N G I N E E RN O R T H C A R O L I N
AP R O F E S S I O N A
LE N G I N E E RF R A N C I S S L I N S K Y, I I I2020-DEC-01
NCNG RAEFORD POV & MOV EXPANSION305 TEAL DRIVE RAEFORD, NORTH CAROLINA, 28376, NCNG# 3720140172 / SCO# 18-19694-01A43358
J. LEWIS
F. SLINSKY
F. SLINSKY
PRELIMINARY PLANS
FOR REVIEW ONLY
DO NOT USE FOR CONSTRUCTION
NAD 830
SCALE 1"=30'
60'30'
C3.2 POST-DEVELOPMENT STORMWATER MANAGEMENT PLAN1" = 30'
1.THE NET INCREASE IN IMPERVIOUS AREA IS CAPTURED AND TREATED IN THE UNDERGROUND DETENTION
WITH STORMFILTERS (DRAINAGE AREA A1).
2.FOR STORMWATER MANAGEMENT, THERE ARE TWO ANALYSIS POINTS, A AND B. ANALYSIS POINT A IS
LOCATED JUST OFFSITE TO THE SOUTHWEST IN AN EXISTING DITCH. ANALYSIS POINT B IS LOCATED IN THE
EXISTING ROADSIDE DITCH TO THE NORTHEAST OF THE SITE.
A.THE DRAINAGE AREA TO ANALYSIS POINT A INCLUDES ONSITE DRAINAGE AS WELL AS SOME OFFSITE
DRAINAGE FROM THE NORTH OF THE SITE THAT FLOWS THROUGH THE SITE AND IS ROUTED THROUGH
THE PROPOSED STORM SYSTEM. DRAINAGE AREA 'A1' IS THE AREA THAT DRAINS TO THE UNDERGROUND
DETENTION WITH STORMFILTERS AND THEN TO ANALYSIS POINT A. DRAINAGE AREA 'A2' INCLUDES
ONSITE AS WELL AS OFFSITE RUNOFF THAT BYPASSES THE SCM AND DRAINS TO ANALYSIS POINT A.
B. THE DRAINAGE AREA TO ANALYSIS POINT B CONSISTS OF ONSITE DRAINAGE ONLY AND IS SHOWN AS
DRAINAGE AREA 'B'. POST DEVELOPMENT RUNOFF HAS BEEN DESIGNED TO BE LESS THAN PRE
DEVELOPMENT RUNOFF FOR THE 1 YEAR, 24 HOUR STORM AT BOTH ANALYSIS POINTS.
3.THIS DRAWING IS FOR AGENCY REVIEW ONLY - NOT FOR CONSTRUCTION.
4.THERE ARE NO WETLANDS ON-SITE, AS DETERMINED BY TIMMONS GROUP.
NOTES
POST-DEVELOPMENT IMPERVIOUS AREA AND WATER QUALITY TREATMENT
POST-DEVELOPMENT IMPERVIOUS (BYPASS)
ANALYSIS POINT A
DRAINAGE
AREA
(Acres)
COMPOSITE C Q1 Q10
POST-DEVELOPMENT
A2 (BYPASS)
3.10 0.66 3.21 3.82
POST-DEVELOPMENT
A1 (SCM)
POST-DEVELOPMENT
A1+A2 (COMBINED)
1.78 0.77
4.88
POST-DEVELOPMENT IMPERVIOUS TREATED IN SCM
POST-DEVELOPMENT STORMWATER QUANTITY CONTROL
NOTE: POST-DEVELOPMENT FLOW IS LESS THAN PRE-DEVELOPMENT FLOW AT ALL ANALYSIS POINTS.
REFER TO CALCULATION BOOKLET FOR ADDITIONAL INFORMATION.
Q100
5.51
DRAINAGE AREA
PRE DEVELOPMENT ONSITE IMPERVIOUS SURFACES (BUILT BEFORE 1997) = 2.16± ACRES
POST DEVELOPMENT ONSITE IMPERVIOUS SURFACES = 3.75± ACRES
IMPERVIOUS AREA REQUIRED TO BE TREATED = 1.59± ACRES
IMPERVIOUS AREA TREATED WITH STORMWATER FILTERS = 1.59 ± ACRES
STORMWATER QUALITY CALCULATIONS
0.70 5.64 6.79 9.20
2.55 2.97 3.69
TIME OF CONCENTRATION FLOW LINE
TIME OF
CONCENTRATION
LINE AREA 'A1'
TIME OF
CONCENTRATION
LINE AREA 'B'
TIME OF
CONCENTRATION
LINE AREA 'A2'
ANALYSIS POINT A
DRAINAGE
AREA
(Acres)
COMPOSITE CPRE-DEVELOPMENT
3.82
Q1 Q10
0.62 7.24 11.42
NOTE: POST-DEVELOPMENT FLOW IS LESS THAN PRE-DEVELOPMENT FLOW AT ALL ANALYSIS POINTS.
REFER TO CALCULATION BOOKLET FOR ADDITIONAL INFORMATION.
Q100
14.83
PRE-DEVELOPMENT STORMWATER QUANTITY CONTROL
ANALYSIS POINT B 1.34 0.65 2.15 3.49 4.66
ANALYSIS POINT B
DRAINAGE
AREA
(Acres)
COMPOSITE C Q1 Q10
POST-DEVELOPMENT STORMWATER QUANTITY CONTROL
Q100
POST-DEVELOPMENT
B1 (BYPASS)
0.28 0.39 0.30 0.48 0.64