20200225 Ver 1_SMP_20200211

Highway North Carolina Department of Transportation
Stor"weit r Highway Stormwater Program
STORMWATER MANAGEMENT PLAN
(Version 2.08; Released April 2018) FOR NCDOT PROJECTS
WBS Element: 39062.1.2 TIP No.: U-4424 County(ies): Edgecombe Page 1 of 2
General Project Information
WBS Element:
39062.1.2 ITIP Number: U-4424
Project Type: Roadway Widening Date: 2/10/2020
NCDOT Contact:
Russell Broadwell, PE
Contractor / Designer:
WSP-USA / John F. Watson, PE
Address:
509 Ward Blvd.
Address:
434 Fayetteville Rd. Suite 1500
PO Box 3165
Raleigh, NC 27601
Wilson, NC 27895
Phone:
(252)-640-6409
Phone:
(919)-376-2704
Email:
rbroadwell(a)ncdot.com
Email:
lohn.f.watson(aDwsp.com
City/Town:
Tarboro
County(ies):
Edgecombe
River Basin(s):
Tar -Pamlico
CAMA County? I
No
Wetlands within Project Limits?
No
Project Description
Project Length (lin. miles or feet):
2.33 Surrounding Land Use: Residential, Agricultural, and Industrial
Proposed Project
Existing Site
Project Built -Upon Area (ac.)
11.3 ac.
9.0 ac.
Typical Cross Section Description:
-L- includes 3-12' paved lanes with 2.5' curb and gutter. Along the length of the project all
-L- includes 2-11.5' paved lanes with grass shoulders and grass lined "v" ditches on
ditch front and back slopes have a minimum grade of 3:1. A 10' side walk starts at 26+02
both sides.
RT and continues along the length of the project.
Annual Avg Daily Traffic (veh/hr/day):
Design/Future: 10,400 Year: 2045
Existing: 9,100 Year: 2016
General Project Narrative:
State project U-4424 is a widening project for NC-111 that adds a shared center lane, curb gutter for closed drainage systems, and a 10' side -street trail along the length of the
(Description of Minimization of Water
project.
Quality Impacts)
Drainage from the beginning of the project will flow away from the project site and tie into two existing roadside ditches. Drainage from -Y- and LT of -L- alignment and drainage
from -Y1- and RT -L- alignment will be collected in two seperate systems, each replicating the existing stormwater pattern without introducing any new drainage area to the
outfall. The proposed drainage system along NC-111, -L- Sta. 20+15 to 32+60 will feature catch basins on both sides that outlet from a closed drainage system into UT to Holly
Creek at -L- Sta. 28+23. This replaces the sheet flow runoff into roadside ditches, while maintaining existing drainage patterns. Toe protection will be installed along the fill
slopes from -L- Sta. 25+00 to 27+50 LT to protect the toe of the fill slope from eroding due to any runoff coming from nearby agriculture fields.
Currently along NC-111, drainage from -L- Sta. 35+90 to 47+07 outlets into UT to Holly Creek at -L- Sta. 40+30. The proposed closed drainage system along this stretch
maintains existing drainage patterns and outlets into standard tail ditch to ensure positive drainage away from the road.
From -L- Sta. 54+35 to 57+97 most of the existing closed drainage system has been retained with some new additions and the cross pipe being upsized to a 48" from a 36".
The two crosspipes at -L- Sta. 96+61 have been replaced with 2-54" RCP filling in the existing ditches from -L- Sta. 96+30 to 96+99 and now outletting onto a riprap lined
special lateral variable width base ditch parallel to -Y5-. The proposed outfall is to be protected with riprap as the existing grass lined outfall is slighty eroded.
At the intersection of -Y8- and -L- there is an existing closed drainage system that outfalls at -L- Sta. 118+10. This system will be replaced with a comparable closed drainage
system that directs roadway drainage to the same location as the existing condition. The new outfall discharges into a defined tail ditch to ensure positive drainage away from
the road.
Stormwater from the left shoulder of the -Y8- alignment to the end of the project will be captured in a closed system along the -L- line and outfall into an existing concrete lined
ditch that discharges into Holly Creek just as in the existing condition.
Waterbody Information
Surface Water Body (1):
UT to Holly Creek
NCDWR Stream Index No.:
28-81-1
NCDWR Surface Water Classification for Water Body
Primary Classification:
Class C
Supplemental Classification:
Nutrient Sensitive Waters (NSW)
Other Stream Classification:
None
Impairments:
None
Aquatic T&E Species?
No Comments:
NRTR Stream ID:
SA, SIB, & SC
Buffer Rules in Effect: Tar -Pamlico
Project Includes Bridge Spanning Water Body?
INo
IDeck Drains Discharge Over Buffer? INo
Dissipator Pads Provided in Buffer? I N/A
Deck Drains Discharge Over Water Body?
I N/A
(If yes, provide justification in the General Project Narrative)
(If yes, describe in the General Project Narrative; if no, justify in the
General Project Narrative)
(If yes, provide justification in the General Project Narrative)

Highway North Carolina Department of Transportation
Stormwa11 Highway Stormwater Program
STORMWATER MANAGEMENT PLAN
(Version 2.08; Released April 2018) FOR NCDOT PROJECTS
WBS Element: 39062.1.2 TIP No.: U-4424 County(ies): Edgecombe Page 2 of 2
Swales
Sheet
No.
Station & Coordinates
(Road and Non Road
Projects)
Surface
Water
Body
Base
Width
(ft)
Front
Slope
(H:1)
Back
Slope
(H:1)
Drainage
Area
(ac)
Recommended
Treatm't Length
(ft)
Actual
Length
ft
Longitudinal
Slope
%
Q2
(cfs)
V2
(fps)
Q10
cfs)
V10
(fps)
Rock
Checks
Used
BMP
Associated w/
Buffer Rules?
4
-L- STA. 14+21 to 16+82 LT
(1)UT to Holly
Creek
0.0
3.0
3.0
0.2
22
263
1.23%
3.0
0.9
0.4
1.0
No
No
4
-L- STA. 16+82 to 18+79 LT
(1)UT to Holly
Creek
0.0
3.0
3.0
0.3
26
200
0.75%
0.4
1.0
0.5
1.1
No
No
4
-L- STA. 14+23 to 18+00 RT
(1)UT to Holly
Creek
0.0
3.0
3.0
1.8
176
378
1.00%
2.4
1.8
3.1
1.9
No
No
4
-Y1- STA. 13+89 to 14+10 RT
(1)UT to Holly
Creek
0.0
6.0
3.0
9.3
930
1952
1.43%
8.8
2.8
12.1
3.0
No
No
4
-Y- STA. 10+50 to 10+97 RT
(1)UT to Holly
Creek
2.0
3.0
3.0
8.7
870
1325
2.29%
13.2
1.9
16.8
2.0
No
No
5
-L- STA. 23+00 to 25+00 LT
(1)UT to Holly
Creek
0.0
3.0
3.0
0.3
25
200
0.52%
0.3
0.9
0.4
1.0
No
No
5
-L- STA. 29+50 to 32+50 LT
(1)UT to Holly
Creek
0.0
3.0
3.0
2.0
204
300
0.50%
1.6
1.4
2.2
1.5
No
No
6
-Y3- STA. 11+00 to 11+30 LT
(1)UT to Holly
Creek
0.0
3.0
3.0
0.2
21
21
0.80%
0.6
1.3
0.8
1.4
No
No
6
-Y4- STA. 10+67 to 11 +00 RT
(1)UT to Holly
Creek
0.0
4.0
3.0
1.0
102
414
2.33%
4.2
2.9
5.5
3.2
No
No
7
-L- STA. 59+20 to 61+00 RT
(1)UT to Holly
Creek
0.0
3.0
3.0
0.2
19
160
3.54%
0.5
1.0
0.7
1.1
No
No
11
-Y7- STA. 11+50 to 11+94 LT
(1)UT to Holly
Creek
0.0
4.0
3.0
0.2
21
47
0.50%
0.3
0.9
0.4
0.9
No
No
11
-Y8- STA. 12+58 to 13+00 LT
(1)UT to Holly
Creek
0.0
3.0
3.0
0.3
30
289
1.37%
1.0
1.7
1.3
2.6
No
No
11
-Y8- STA. 12+58 to 13+04 RT
(1)UT to Holly
Creek
0.0
3.0
3.0
2.2
220
270
2.53%
3.4
2.6
4.3
3.4
No
No
Additional Comments