20191232 Ver 1_R-0211EC_HYD_SMP_20190916

ig'htway North Carolina Department of Transportation t
Stormter., Highway Stormwater Program
STORMWATER MANAGEMENT PLAN
(Version 2.08; Released April 2018) FOR NCDOT PROJECTS
WBS Element: TIP No.: R-0211EC County(ies): Mecklenburg Page 1 of 3
General Project Information
WBS Element:
ITIP Number: R-0211EC Project Type: Roadway Widening Date: 6/7/2019
NCDOT Contact:
Malcolm Watson
Contractor / Designer:
Blythe Construction/WSP Karl Dauber
Address:
1020 Birch Ridge Drive
Address:
1001 Morehead Square Drive
Raleigh, NC 27610
Suite 610
Charlotte, NC 28203
Phone:
[phone]
Phone:
[phone]
Email:
mcwatson ncdot. oy
Email:
Karl. Dauber WSID.COM
City/Town:
Charlotte
Coun ies :
Mecklenburg
River Basin(s):
Catawba
CAMA County?
I No
Wetlands within Project Limits?
Yes
Project Description
Project Length (lin. miles or feet):
0.8 miles Surrounding Land Use: Urban (residential and commercial)
Proposed Project
Existing Site
Project Built -Upon Area (ac.)
14.1 ac.
13.7 ac.
Typical Cross Section Description:
There are several cross sections for this project in the typicals provided with the Redline
There are 2 existing cross section on 485.
Drainage Plans. Essentially, the project adds toll lanes in the median. In some cases a
- 3 lanes each direction with a paved median from 77- to Johnston Road.
ditch section is revised to provide pavement. In other cases a large paved median is
Then as you travel east its is 2 lanes either direction with a variable width grassed
reduced to account for this new traffic pattern.
median to US-74.
Annual Avg Daily Traffic (veh/hr/day):
Design/Future: 1592 Year: 2040
Existing: 1186 Year: 2015
General Project Narrative:
The NCDOT is widening a section of I-485 that lies within the municipal boundaries of the Cities of Charlotte and Matthews. The Design -Build Project 1-5507 / R-0211 EC / U-
(Description of Minimization of Water
4714AB will provide an eastbound and westbound Express Lane within the 1-485 median from 1-77 to US 74 (Independence Boulevard), a distance of approximately 16.6 miles.
Quality Impacts)
The project will also provide an 1-485 / Weddington Road interchange, and modify the 1-485 / East John Street - Old Monroe Road interchange
The Impacts for R-0211 EC are located on Sheets 60 and 61 of the plan set and are in relation to the widening of 485 that is needed to accomodate a new interchange at
Weddington Road.
Construction will unavoidably impact several streams. Where practicable, 2:1 slopes will be used to minimize impacts. Where culverts are being extended in jurisdictional
streams rip rap for stabilization is being installed on banks only.
Best Management Practices:
*Dry Detention Basin.
*Promotion of sheet flow and infiltration with grassed shoulders except were shoulder berm gutter was required.
*Drainage systems outlet to rip rap pads or riprap lined ditches.
*Riprap on embankments was used to prevent erosion where ditches enter streams.
Surface Water Body (1):
Fourmile Creek
NCDWR Stream Index No.:
11-137-9-4
NCDWR Surface Water Classification for Water Body
Primary Classification:
Class C
Supplemental Classification:
Other Stream Classification:
None
Impairments:
None
Aquatic T&E Species?
Comments:
NRTR Stream ID:
1SBF SBE
Buffer Rules in Effect: N/A
Project Includes Bridge Spanning Water Body?
INo
I Deck Drains Discharge Over Buffer? INo
Dissipator Pads Provided in Buffer? I N/A
Deck Drains Discharge Over Water Body?
IN2
(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 a 4,
SYOCYYIwatel Highway Stormwater Program
STORMWATER MANAGEMENT PLAN
(Version 2.08; Released April 2018) FOR NCDOT PROJECTS
WBS Element: TIP No.: R-0211EC County ies : Mecklenburg Page 2 of 3
Preformed Scour Holes and Energy Dissipators
Sheet
No.
Station & Coordinates
(Road and Non Road
Projects)
Surface
Water Body
Energy Dissipator
Type
Riprap Type
Drainage
Area
(ac)
Conveyance
Structure
Pipe/Structure
Dimensions
(in)
Q10
(cfs)
V10
(fps)
BMP
Associated w/
Buffer Rules?
60
-L-790+50LT
(1)Fourmile
Creek
PSH
Class'B'
0.7
Pipe
15
3.5
12.3
No
Additional Comments
' Keter to the NUUU I best Management Practices I 001boX (Lu14), NUUU I Standards, the rederal Highway Admmistration (r HVVA) HydraUllC Engineering Urcular No. 14 (HEU-14), I hlyd Laition, HyaraUlIC Uesign or Energy
Dissipators for Culverts and Channels (July 2006), as applicable, for design guidance and criteria.

Highway North Carolina Department of Transportation t
Stormwater;
Highway Stormwater Program
STORMWATER MANAGEMENT PLAN
(Version 2.08; Released April 2018) FOR NCDOT PROJECTS
WBS Element: TIP No.: R-0211EC Count ies : Mecklenburg Page 3 of 3
Other Best Management Practices
Sheet No.
Station & Coordinates
(Road and Non Road Projects)
Surface
Water Body
BMP Type
Drainage Area
(ac)
New Built -Upon
Area
(ac)
Volume Treated
(ac-ft)
Precipitation Depth
Treated over NBUA
(in)
BMP Associated
w/ Buffer Rules?
59
Y5LPD- 20+00 RT
Four Mile Creek
Dry Detention Basin
13.8
6.4
0.745
1.47
No
Weddington Road
Additional Comments