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North Carolina Department of Transportation `!_
Highway Stormwater Program JI
STORMWATER MANAGEMENT PLAN
(Version 3.00; Released August 2021) FOR NCDOT PROJECTS
WBS Element: 50168.1.1 TIP/Proj No: U-5748 County(ies): Wake Page 1 of 2
General Project Information
WBS Element:
50168.1.1 ITIP Number: IU-5748 Project Type: 'Roadway Widening IDate: 110/14/2021
NCDOT Contact:
Ray Lovinggood
Contractor / Designer:
AECOM / Meme Buscemi
Address:
NCDOT Hydraulics Unit
1000 Birch Ridge Drive
Raleigh, NC 27610
Address:
5438 Wade Park Boulevard, Suite 200
Raleigh, NC 27607
Phone:
919-906-0480
Phone:
919-461-1100
Email:
rlovinppood(ilncdot.00v
Email:
meme.buscemi(ilaecom.com
City/Town:
Raleigh, NC
County(ies):
Wake
River Basin(s):
Neuse i
CAMA County?
No
Wetlands within Project Limits?
Yes I
' Project Description
Project Length (lin. miles or feet):
1.3 miles I Surrounding Land Use: 'Residential, Wooded
a Proposed Project
Existing Site,
Project Built -Upon Area (ac.)
27.0 lac.
18.1 ac.
Typical Cross Section Description:
8-lane, raised median, divided. Some curb and gutter with storm sewer. Some paved
shoulder with roadside ditches. New greenway path connection. Bridge widening over the
Neuse River.
6-lane, grass median, divided. Shoulder section with 12' lanes. Roadside ditches and
storm sewer.
Annual Avg Daily Traffic (veh/hr/day):
Design/Future:I 57,821 I Year:I2041
Existing:I 37,404 I Year:l 2021
General Project Narrative: The project is to upgrade the high -volume intersection of US 401 at Ligon Mill Road and Mitchell Mill Road in Raleigh, NC. The design includes a "continuous -flow" intersection with
(Description of Minimization of Water Mitchell Mill Road and an "offset tee intersection with Ligon Mill Road. US 401 will be widened from a 6-lane divided highway to an 8-lane divided highway. Major hydraulic structure
Quality Impacts) changes include the widening of the Neuse River bridge and replacement of a culvert carrying an unnamed tributary to the Neuse River. Water from the travel lanes of the Neuse
River bridge will not directly discharge to the river. Roadway water dischargeing directly to the Neuse River buffered areas will discharge onto riprap bank stabilization pads to
prevent erosion. Existing pipe structures within the buffer zones of the Neuse River were maintained where possible in an effort to minimize disturbance.
Existing drainage patterns were maintained as best possible.
Roadway fill slopes were steepened where possible in an effort to minimize wetland impacts.
Stormwater management is accomplished in grass ditches where possible. Lined ditches and storm sewer are also used on the project where needed. Site conditions did not allow
for ditches within buffers to meet swale criteria.
Ditches through buffer zones were designed to meet swale criteria as best as possible. Generally, existing ground conditions that heavily impacted proposed ditch slopes did not
allow for designed ditches to meet swale criteria.
Riprap energy dissipators are used at pipe outlets to reduce discharge velocity to non -erosive levels.
Bridge runoff is not dishcarged directly into the Neuse River. Deck drain discharge within the buffer zones are outlet onto rip rap dissipator pads.

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North Carolina Department of Transportation F ti
Highway Stormwater Program s:
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STORMWATER MANAGEMENT PLAN ':•
(Version 3.00; Released August 2021) FOR NCDOT PROJECTS
WBS Element: 50168.1.1 TIP/Proj No.: U-5748 County(ies): Wake Page 2 of 2
General Project Information
Waterbody Information
Surface Water Body (1): Neuse River
NCDWR Stream Index No.:
27-(22.5)
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:
Buffer Rules in Effect: Neuse
Project Includes Bridge Spanning Water
Body?
Yes
Deck Drains Discharge Over Buffer? Yes
Dissipator Pads Provided in Buffer? Yes
Deck Drains Discharge Over Water Body?
No
(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 Na
rative)
Surface Water Body (2):
NCDWR Stream Index No.:
NCDWR Surface Water Classification for
Water Body
Primary Classification:
Supplemental Classification:
Other Stream Classification:
Impairments:
Aquatic T&E Species?
I Comments:
NRTR Stream ID:
Buffer Rules in Effect:
Project Includes Bridge Spanning Water Body?
Deck Drains Discharge Over Buffer?
_
Dissipator Pads Provided in Buffer?
Deck Drains Discharge Over Water Body?
(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 Na rative)
Surface Water Body (3):
NCDWR Stream Index No.:
NCDWR Surface Water Classification for Water Body
Primary Classification:
Supplemental Classification:
Other Stream Classification:
Impairments:
Aquatic T&E Species?
Comments:
NRTR Stream ID:
Buffer Rules in Effect:
Project Includes Bridge Spanning Water Body?
Deck Drains Discharge Over Buffer?
Dissipator Pads Provided in Buffer?
Deck Drains Discharge Over Water Body?
(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 Na rative)