20240065 Ver 1_WestbournePCNCoverLetter_20240104

PREPARED FOR:
U.S. Army Corps of Engineers, Charlotte Regulatory Field Office
8430 University Executive Park Drive, Suite 61 S
Charlotte, NC 28262
S&ME, Inc.
2016 Ayrsley Town Blvd. Suite 2A
Charlotte, NC 28273
January 4, 2024

January 4, 2024
U.S. Army Corps of Engineers
Charlotte Regulatory Field Office
8430 University Executive Park Drive, Suite 615
Charlotte, North Carolina 28262
Attention: Sam Dailey
North Carolina Department of Environmental Quality
Division of Water Resources, Winston Salem Regional Office
450 Hanes Mill Road, Suite 300
Winston-Salem, NC 27105
Attention: Sue Homewood
Reference: Pre -Construction Notification/Regional General Permit 163
and General Water Quality Certification 4508
Westbourne Storm Drainage Improvement Project (SDIP)
Charlotte, Mecklenburg County, North Carolina
Dear Ms. Dailey and Ms. Homewood:
On behalf of Charlotte Storm Water Services (CSWS), S&ME, Inc. (S&ME) is pleased to submit this application for
Department of the Army verification of impacts to Waters of the U.S. in accordance with Regional General Permit
(RGP) No. 163 and a request for Individual 401 North Carolina Water Quality Certification (WQC) as the project
exceeds the thresholds for General Certification (GC) 4508. CSWS will be considered the applicant, and Noah
Meador of CSWS will act as the signatory on the electronic Pre -Construction Notification (PCN) for this project.
In addition to the brief project summary provided herein, please find the following enclosed:
Project Figures
Appendix I: 100% Design Plans
Appendix II: Jurisdictional Determination Package / Site Photographs
Appendix III: Protected Species Documentation
Appendix IV: Cultural Resources Documentation
S&ME, Inc. 12016 Ayrsley Town Blvd. Ste. 2-A I Charlotte, INC 28273 S&ME Project No. 23350081 B

Pre -Construction Notification/Regional General Permit 163
Westbourne Storm Drainage Improvement Project (SDIP)
III Charlotte, Mecklenburg County, North Carolina
s
S&ME Project No. 22350081 B
If you need additional information or have questions, please contact Dave Homans at 704-900-9394 or
[e-mail].
Sincerely,
S&ME, Inc.
D. David Homans
Project Scientist
[e-mail]
(Documents reviewed and approved by Noah Meador with Charlotte Storm Water Services)
January 4, 2024

Pre -Construction Notification/Regional General Permit 163
Westbourne Storm Drainage Improvement Project (SDIP)
Charlotte, Mecklenburg County, North Carolina III
S&ME Project No. 22350081 B S
Table of Contents
1.0 Project Information and Description............................................................................1
2.0 Purpose and Need.............................................................................................................1
3.0 Existing Jurisdictional Waters on Site..........................................................................1
4.0 Proposed Impacts to Jurisdictional Waters..................................................................2
5.0 Avoidance and Minimization / Mitigation..................................................................4
6.0 Protected Species and Historical and Cultural Resources........................................4
7.0 Additional Regulatory Considerations........................................................................5
List of Tables
Table 4-1: Proposed Project Impacts......................................................................................................... 3
Figures
Appendices
Appendix I —100% Design Plans
Appendix II — Jurisdictional Determination Package, Including Site Photographs
Appendix III — Protected Species Documentation
Appendix IV — Cultural Resources Documentation
January 4, 2024

Pre -Construction Notification/Regional General Permit 163
Westbourne Storm Drainage Improvement Project (SDIP)
Charlotte, Mecklenburg County, North Carolina III
S&ME Project No. 22350081 B S
1.0 Project Information and Description
The proposed project is a neighborhood -wide storm drainage improvement project (SDIP) centered around
Westbourne Drive in the Oakdale South neighborhood of Charlotte, North Carolina. The project will involve
numerous stormwater infrastructure and channel improvements across approximately 1.4 acres of work areas.
Project work includes culvert upgrades and replacements, installation of headwalls and riprap aprons, and
stabilization of the channel with plunge pool and rock step grade transitions. Additionally, an area of bank
stabilization using vegetated geogrid soil lifts in conjunction with a rock -armored bank toe is proposed.
CSWS is submitting this PCN for approval under the RGP 163. Please note that the proposed jurisdictional
impacts for this project meet the special conditions of RGP 163 and fall below the notification thresholds
established therein; as such this PCN is being submitted to the USACE for the record only. The proposed project
has been designed to be in general accordance with GC 4508; as both the 300-bank-foot threshold for bank
stabilization with hard armoring and the 150-linear foot (LF) threshold established for permanent impacts
established in GC 4508 are exceeded by this project, CSWS is requesting this project be approved as an Individual
401 WQC.
Additional information regarding this project is contained in the body of the electronic PCN application. Refer to
Figure 1 (Vicinity Map), Figure 2 (Topographic Map), Figure 3 (Site Map /Jurisdictional Waters of the U.S. Map)
and Figures 4-9 (Proposed Project Impacts) as well as Appendix 1 (100% Design Plans) and Appendix II
(Jurisdictional Determination Package / Site Photographs) for additional site and project design information.
2.0 Purpose and Need
The purpose of the project is to upgrade and repair existing undersized, perched, and degraded stormwater
infrastructure with structures that are compliant with current engineering requirements. Channel stabilization is
also proposed for an unstable section of channel that is actively eroding. Upgrades will address roadway flooding
concerns, reduce the risk of further channel erosion associated with culvert outfalls, and improve channel
conditions in channels that are currently experiencing excessive erosion. Temporary impacts will also be required
for the installation of pump -around measures so that work can be performed in the dry, and for transitioning
channel banks into new headwalls. Please see Table 4-1 for a further discussion of the purpose and need for each
proposed jurisdictional impact associated with this SDIP.
3.0 Existing Jurisdictional Waters on Site
The project site was delineated by Helen Simonson of CSWS in April 2019 and was reassessed by Noah Meador of
CSWS in October of 2023. A request for jurisdictional determination is included along with site photographs in
included in Appendix II of this PCN. The following Jurisdictional Waters were identified on site:
Stream A: This non -wetland relatively permanent water is an unnamed tributary to Gum Branch in the
Upper Catawba Basin (HUC 03050101). Approximately 603 linear feet (LF) of this channel was observed in
the proposed project work area, making up most of the jurisdictional waters in the project area. At the
January 4, 2024

Pre -Construction Notification/Regional General Permit 163
Westbourne Storm Drainage Improvement Project (SDIP)
Charlotte, Mecklenburg County, North Carolina I I I
S&ME Project No. 22350081 B r
uppermost end of the project area the channel scored a 27.5 on the NC Division of Water Quality (NC
DWQ) Stream Identification Form, indicating intermittent flow, while the stream scored a 33.5 along the
lower reaches, indicating perennial flow. The channel was rated "low" quality by the North Carolina
Stream Assessment Method (NC SAM) at both areas where this channel was assessed.
• Stream B: This non -wetland relatively permanent water is a tributary to Stream A. Approximately 48 LF of
this channel is present in the project work area, though no direct impacts are proposed to this channel.
Upstream from the project area, this channel scored a 29.5 on the NC DWQ Stream Identification Form,
indicating intermittent flow. The channel was rated "low" quality by the NC SAM.
An additional drainage was assessed at an area where culvert improvements are proposed under Balfour Lane
(See Figure 7). This drainage (NJD1) did not exhibit a consistent ordinary high water mark, lacked soil based
evidence of a connection to the water table, and scored a 10 on the NC DWQ Stream Identification Form,
indicating an ephemeral flow. As ephemeral channels are not considered relatively permanent waters, this
drainage was determined to not be a jurisdictional waters of the U.S. A Jurisdictional Determination request,
including stream assessment forms and site photographs, is included in Appendix II of this PCN.
4.0 Proposed Impacts to Jurisdictional Waters
The proposed project will require impacts to Stream A. Project impacts are shown on Figures 4 through 9 and in
the attached 100% Design Drawings in Appendix I. Refer to Table 4-1 on the following pages for a summary of
stream impacts.
Total project impacts include 110 LF of temporary impacts, 53 LF of permanent impact with loss of stream bed,
and 393 LF of permanent impact associated with armored bank stabilization for a grand total of 446 linear feet of
permanent impact. As armoring is occurring along both banks of the channel for an approximately 176-foot
portion of the bank stabilization area (Impact 11), the total amount of streambank length undergoing armored
stabilization is 569 bank feet.
As the proposed project impacts are below the thresholds specified in RGP 163, written notice in the form of a
PCN and written confirmation from USACE is not required, therefore this PCN is being submitted to the USACE
"for the record only". As the GC 4508 threshold of 300 bank feet for non -natural armoring and 150 linear feet of
permanent impacts has been exceeded, this PCN is being presented to the NCDWR for authorization under an
Individual Water Quality Certification.
January 4, 2024

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Pre -Construction Notification/Regional General Permit 163
Westbourne Storm Drainage Improvement Project (SDIP)
Charlotte, Mecklenburg County, North Carolina III
S&ME Project No. 22350081 B S
5.0 Avoidance and Minimization / Mitigation
The project was designed to reduce flood and erosion risk and improve bank conditions while minimizing the
disturbance to adjacent areas. Though space constraints and the severity of channel erosion precluded the use of
natural channel design stabilization, the vegetated geogrid soil lift with rock toe stabilization method proposed
uses natural design principles to the extent practicable while still armoring the channel toe in a way that is likely to
prevent future erosion. Riprap dissipator aprons were limited to the minimum extent necessary to meet design
standards and were primarily located in areas that had already been impacted by riprap fill. Culverting of open
channel was limited to only one very small area of riprap filled channel with little to no functional habitat value.
Additionally, changes to the structures of larger culverts were made to maximize aquatic life passage, such as the
inclusion of internal culvert baffles to establish a consistent baseflow channel and maintain a natural substrate bed
within in the culvert.
During construction, appropriate sediment and erosion control practices equaling those outlined in the most
recent version of the "North Carolina Sediment and Erosion Control Planning and Design Manual" will be used to
minimize impacts to the stream. Temporary coffer dams and a pump around will be used so that work will occur
"in -the -dry", and the pump around has been designed to minimize impact to adjacent areas. Tree protection will
be used to avoid impacts to trees that are not required to be cut within the project area.
The proposed project results in significantly less than 150 LF of permanent loss of stream bed, the threshold of
impact typically requiring mitigation. Additionally, project activities have been designed to improve the stability
and functional value of the channel undergoing bank stabilization. As such, no additional compensatory
mitigation should be required for this project.
6.0 Protected Species and Historical and Cultural Resources
To comply with applicable sections of the Endangered Species Act of 1973 (16 USC 1531-1543, S&ME performed
a North Carolina Natural Heritage Program (NCNHP) Database review to identify are species, important natural
communities, natural areas, and/or conservation/managed areas within the proposed project within a mile radius
of the project boundary. Additionally, the U.S. Fish and Wildlife Service (USFWS) IPaC (Information for Planning
and Consultation) online service was used to generate a list of federally protected threatened or endangered
species which may be present in the project area (See Appendix III).
The NCNHP review indicated that no extant populations of federally protected species were present within a one -
mile radius of the project. The USFWS IPaC review identified the following species that may be in the project area
with current federal protections:
Michaux's sumac — Rhus michauxii (Endangered)
Smooth coneflower— Echinacea laevigata (Endangered)
Schweinitz's sunflower - Helianthus schweinitzii (Endangered)
Typical habitat for the three plant species listed above includes open areas such as infrequently maintained
roadsides, utility rights -of -way, and open wooded areas maintained by fire. The habitat present within the project
January 4, 2024 4

Pre -Construction Notification/Regional General Permit 163
Westbourne Storm Drainage Improvement Project (SDIP)
Charlotte, Mecklenburg County, North Carolina I I I
S&ME Project No. 22350081 B
work area was limited to maintained lawns and lightly wooded riparian areas dominated by invasive vegetation.
As appropriate habitat for these species is not present within the proposed project area, the project was
determined to have no effect on these species.
In order to determine consistency with the Section 106 of the National Historic Preservation Act, a 1-mile radius
around the project site was reviewed for known historic properties using the NC State Historic Preservation Office
(NC SHPO) HPOWEB online mapping tool (See Appendix IV). No properties or districts that were listed in or
determined eligible for the Nation Register of Historic Places were identified within this radius. Additionally, as
the project area occurs largely within the footprint or directly adjacent to existing stormwater infrastructure, it is
unlikely to encounter unidentified archeological resources.
7.0 Additional Regulatory Considerations
As shown on Figure 3, the proposed project work areas are located outside of the Federal Emergency
Management Agency's (FEMA) regulated floodplains and will not result in impacts to these regulated floodplain
areas. Culvert replacements and upgrades within jurisdictional channels have been specifically designed with
internal baffles and low -flow channels to meet aquatic life passage requirements in instances where the culverts
are not connected to extensive upstream pipe networks. In -channel stabilization features have also been
designed to meet minimum aquatic life passage requirements. Culverts have been designed to not restrict the
flow of waters of the U.S. and to allow passage of flood flows while maintain base flow channels.
All jurisdictional features impacted by this project are classified as low functional value by NC SAM metrics. None
of the proposed impacts associated with the project occur in special designated waters or unique wetlands, or
waters protected by state buffer regulations.
The proposed project is not part of a compensatory mitigation project; though the channel stabilization proposed
uses natural channel design principles to the extent practicable and improvements to channel functional value is
likely to occur from the proposed project, no compensatory mitigation credit generation is requested. No aspect
of this project involves construction of culverts for the purpose of creating high ground at the request of a
property owner. Natural channel design principals including the use of vegetated geogrid lifts have been used to
the maximum extent practicable for this project, and riprap use has been minimized to the maximum extent
practicable.
January 4, 2024

Project Figures:
Figure 1 —Vicinity Map
Figure 2 — USGS Topographic Map
Figure 3 — Site Map / Jurisdictional Waters of the U.S. Map
Figures 4-9 — Proposed Project Impacts