20220840 Ver 1_Running Creek Rd SW Plans_20220623

(Version 2.08; Released April 2018)
17BP.7.R.134 TIP No.:400183 County(ies):Guilford Page 1 of 2
TIP Number:Date:
Phone:Phone:
Email:Email:
County(ies):
CAMA County?
No
Design/Future:Year:2025 Existing:Year:
Aquatic T&E Species?No Comments:
No N/A
N/A
Wetlands within Project Limits?
Nutrient Sensitive Waters (NSW)
None
Supplemental Classification:None
Wooded, agricultural
UT to Haw River
0.4
0.142 miles
Project Description
Proposed Project
Cape FearRiver Basin(s):
City/Town:
0.6
Typical Cross Section Description:
Surrounding Land Use:
General Project Narrative:
(Description of Minimization of Water
Quality Impacts)
No
[e-mail]
Greensboro, NC 27415
Address:
1/14/2021
GuilfordGibsonville
Tim Powers, PE
1584 Yanceyville Street, PO Box 14996
WBS Element:
Bridge ReplacementWBS Element:
Eleni M. Riggs, PENCDOT Contact:
[phone]
7621 Purfoy Road, Suite 115
Fuquay Varina, NC 27526
Contractor / Designer:
[phone]
Mott MacDonald
North Carolina Department of Transportation
Highway Stormwater Program
STORMWATER MANAGEMENT PLAN
FOR NCDOT PROJECTS
Project Type:
Highway Division 7 Address:
General Project Information
40018317BP.7.R.134
Impairments:
Other Stream Classification:
Primary Classification:
Project Built-Upon Area (ac.)
None
The North Carolina Department of Transportation (NCDOT) has proposed to replace Guilford County Bridge #183 on Running Creek Rd (SR 2710) over UT to Haw River. The
existing structure is a one span bridge (1@33'-4") and is a timber deck on I-Beams with a 14' bed to crown. The proposed structure is a 2 @ 12' x 10' Reinforced Concrete Box
Culvert (RCBC). This structure has been designed to have as little environmental and surface water impacts as possible. This structure meets the hydrological requirements of
the drainage area and matches or reduces upstream backwater in all events analyzed. The proposed culvert will function similarly to that of the existing bridge, which consists of
timber vertical abutments and wingwalls. The existing stream also approaches the upstream side of the bridge at a sharp skew with some locations of bank erosion. The
proposed culvert provides a better alignment with the stream and bank stabilization in the vicinity of the crossing. There are no wetlands present in this project. Channel
improvements were made for the proposed RCBC design. Excavation is kept to a minimum to produce as little impact as possible. Where excavation is necessary, geotextile
and rip-rap are utilized for bank stabilization in order reduce stream bank erosion. A low flow barrel on the west side of the culvert was designed to match the stream width to
maintain the normal flow width, depth, and velocity of the stream. This will maintain sediment transport to provide a stable stream during bankfull discharge. The barrel invert will
be a minimum of 1' below the stream bed to consider fish passage. A high flow barrel on the east side of the culvert will provide flood conveyance during the high flow storm
events. This will reduce shear stress on the stream bottom. There are existing ditches located in all four quadrants of the project. The existing ditches will be retained and
modified. In the NE quadrant, there is a lateral V ditch that is initially grass lined and then transitions into being lined with Class B rip-rap and discharges into the UT to Haw
River. In the SE quadrant, there is a lateral V ditch that ties into an existing roadside V ditch and is discharged into the adjacent wooded area within the buffer to remove
pollutants via infiltration. In the SW quadrant, there is another lateral V ditch that ties into an existing ditch and is discharged along the toe into the adjacent wooded area within
the buffer to remove pollutants via infiltration. In the NW quadrant, there is an existing ditch that ties into a PSRM lined ditch that transitions into a Class B rip-rap lined lateral V
ditch and discharges into a rip-rap outlet pad to dissipate energy to provide a non erosive flow into the stream. The water flows through the ditch before being discharged into the
UT to Haw River. Due to the nature of low impact bridge replacement, the increases in stormwater discharges (post v. pre condition) are negligible. Therefore additional
stormwater measures are not required.
Jordan LakeBuffer Rules in Effect:
None
60
Running Creek Rd (SR 2710): 2 paved lanes (total 22' wide), 6' shoulder on each side (9'
with guardrail). The first 4' of shoulder are paved.
Waterbody Information
2000
NCDWR Stream Index No.:
NRTR Stream ID:
Annual Avg Daily Traffic (veh/hr/day):
Existing Site
Project Length (lin. miles or feet):
ac.
Surface Water Body (1):
Water Supply IV (WS-IV)NCDWR Surface Water Classification for Water Body
ac.
Running Creek Rd (SR 2710): 2 paved lanes (total 20' wide), 10' unpaved shoulder on
each side
120
[e-mail]
Project Includes Bridge Spanning Water Body?Deck Drains Discharge Over Buffer?Dissipator Pads Provided in Buffer?N/A
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 Narrative)
(Version 2.08; Released April 2018)
17BP.7.R.134 TIP No.:400183 County(ies):Guilford Page 2 of 2
Sheet No.:4 Station:14+77 -L-
Sq. Miles
Barrel Height (ft):
Culvert Length (ft)
%
%
Evaluate/Describe Roadway Geometric Constraints:
None
Proposed Culvert 2-yr Outlet Velocity (ft/s):3.5
Natural Stream Channel 10-yr Velocity (ft/s):4.3
Proposed Culvert 10-yr Outlet Velocity (ft/s):5.1
Roadway Geometric Considerations
Bank Stabilization:Class II rip-rap
Natural Stream Channel 2-yr Velocity (ft/s):3.2
Outlet Velocities
Bends at Inlet/Outlet?
(describe culvert alignment with stream)
No
Stream Realignment Necessary? (provide
justification)
No
Culvert/Stream Alignment
Stream Patterns Upstream and Downstream of
the Culvert that Could Affect Fish Passage and
Bank Stability:
There are no concerns upstream or downstream for either culvert at the project location
Bed Forms Impacted by Culvert (riffles, pools,
glides, etc.):
The channel bed forms will return to a more natural condition over time with the elimination of the existing bridge. The existing bridge geometry
allowed the stream to widen to almost double the natural state.
Low Flow Floodplain Bench Required?
(provide justification)
Yes A 2' sill will be constructed in the east barrel in the floodplain to account for flood events
12' low flow channel to match existing
conditions
Proposed Sills/Baffles:Sills at inlet and outlet (1' high in west barrel, 2' high in
east barrel)Existing Low Flow Velocities in the
Stream (ft/s):1.6
Proposed Low Flow Velocities Through
the Culvert (ft/s):1.8
Alternating Low Flow Sills/Baffles:None
Culvert Burial
Proposed Culvert Burial Depth (ft):1
Existing Streambed Material:Sandy Clay Proposed Low Flow Dimensions
Through the Culvert:
Avoidance and Minimization Efforts:
(Bridge to Culvert)
Channel improvements were made for the proposed RCBC design. Excavation is kept to a minimum to produce as little impact as possible.
Where excavation is necessary, geotextile and rip-rap are utilized for bank stabilization in order reduce stream bank erosion. A low flow barrel on
the west side of the culvert was designed to match the stream width to maintain the normal flow width, depth, and velocity of the stream. This will
maintain sediment transport to provide a stable stream during bankfull discharge. The barrel invert will be a minimum of 1' below the stream bed to
consider fish passage. A high flow barrel on the east side of the culvert will provide flood conveyance during the high flow storm events. This will
reduce shear stress on the stream bottom. Further justification of this change are as follows. The basin drainage area and estimated discharges
are compatible with a culvert structure. Secondly, culvert option is typically preferred due to it longer service life and reduced maintenance vs a
bridge. The proposed culvert and existing bridge (with vertical timber abutments) have similar hydraulic type openings and properties. Hydraulic
function including backwater, outlet velocities, etc will remain similar. The downstream, outlet channel has some erosion on the west (LT) bank.
The upstream, inlet channel has some erosion on the east (RT) bank. The proposed bank stabilization will improve bank stability the vicinity of the
crossing.Stream Slope Fish and/or Aquatic Life Passage
Existing Average Stream Slope (%):0.19 Existing Low Flow Channel Dimensions
in the Stream:
12'-14' minimum width
Proposed Culvert Slope (%):0.17
Surface Water Body:(1)UT to Haw River
65Culvert Type:RCBC
10
Proposed Structure Summary
Sheet No. & Station
Drainage Area (ac or sq mi):2.74
Number of Barrels:2
Barrel Width/Diameter (ft):12
North Carolina Department of Transportation
Highway Stormwater Program
STORMWATER MANAGEMENT PLAN
FOR NCDOT PROJECTS
WBS Element:
Bridge to Culvert Avoidance and Minimization