20200349 Ver 3_9b_BlueRidgeRoad_USACE RFI & 401 Modification_20220823

USACE RFI (March 23, 2020) Response
Permit Modification Request

Richards, Mackenzie
From: Richards, Mackenzie
Sent: Tuesday, April 28, 2020 1:13 PM
To: Phillips, George L CIV USARMY CESAW(USA)
Cc: Sullivan, William; Ridings, Rob
Subject: RE: Blue Ridge Road (SR 1670) Widening /SAW-2018-00496/ Incomplete Application
Notification
Attachments: 01_BlueRidgeRoad_PCN_ImpactTables.pdf; 02_BlueRidge_Permit
Drawings_Streams_(2020-04-27).pdf, 03_Blue Ridge Road Widening DMS Acceptance
Letter April 2020.pdf
Good afternoon Lyle,
Based on the discussion that we had over the phone yesterday, I have updated and included the Stream Impact Permit
Drawings(see attached) and the PCN Impact Tables (see attached)for the proposed Blue Ridge Road (SR 1670)
Widening. The permanent stream impacts due to the culvert replacement have increased from 6 LF to 57 LF at Site 2,
resulting in a total of 72 LF of permanent stream impacts due to the culvert replacement for the proposed project.
Permanent stream impacts due to bank stabilization at Site 2 decreased from 112 LF to 61 LF for the proposed project.
Compensatory mitigation at a 1:1 ratio has been proposed for the 72 linear feet of permanent impacts to House Creek
due to the culvert replacement and an updated DMS In-Lieu Fee Acceptance has been included as well (see attached).
Please let me know if you have any questions or you need any additional documentation to complete your review!
Thank you for your time!
Sincerely,
Mackenzie Richards
Kimley-Horn 1 421 Fayetteville Street, Suite 600, Raleigh, NC 27601
Direct: 919 678 4154 1 Mobile:[phone]
Connect with us:Twitter I Linkedln I Facebook I Instagram I Kimley-Horn.com
Celebrating 13 years as one of FORTUNE's 100 Best Companies to Work For
From: Phillips, George L CIV USARMY CESAW (USA)<George.L.Phi Ili [e-mail]>
Sent: Monday, April 27, 2020 10:33 AM
To: Richards, Mackenzie<[e-mail]>
Subject: RE: Blue Ridge Road (SR 1670)Widening/SAW-2018-00496/Incomplete Application Notification
Hey Mackenzie,
Do you have time to discuss the above referenced project this afternoon?
I have a meetings that should be finished by 230pm.Are you available around 300pm?
Lyle Phillips
Regulatory Specialist
US Army Corps of Engineers
CE-SAW-RG-R
i

3331 Heritage Trade Drive, Suite 105
Wake Forest, North Carolina 27587
Phone: [phone], Ext. 25.
Fax: [phone]
Email: [e-mail]
From: Richards, Mackenzie<[e-mail]>
Sent:Thursday,April 23, 2020 10:33 AM
To: Phillips, George L CIV USARMY CESAW(USA)<[e-mail]>; Ridings, Rob
<[e-mail]>
Cc: Goss, Stephanie<[e-mail]>;Sullivan, William <[e-mail]>
Subject: [Non-DoD Source] RE: Blue Ridge Road (SR 1670)Widening/SAW-2018-00496/Incomplete Application
Notification
Good morning!
On behalf of our client, the City of Raleigh, Kimley-Horn is submitting the enclosed additional information for the above
referenced project in response to the U.S. Army Corps of Engineers (USACE) additional information request received on
March 23, 2020.Additionally,the City of Raleigh is requesting a modification to the previously approved General Water
Quality Certification 4135 and Buffer Authorization (NCDWR#20200349) due to changes in the utility design and
easement acquisition. Due to the large file size of the application package, I have attached the file via Citrix Files and it
can be downloaded by clicking the link below.
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_BlueRidgeRoad_RFI_401modification_202...423.pdf 31.2 MB
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can send you the PDF.
Please let me know if you have any questions or you need any additional documentation to assist in your review!
Thank you for your time!
Sincerely,
Mackenzie Richards
Kimley-Horn 1 421 Fayetteville Street, Suite 600, Raleigh, NC 27601
Direct: 919 678 4154 1 Mobile:[phone]
Connect with us:Twitter I Linkedln I Facebook I Instagram I Kimley-Horn.com
Celebrating 13 years as one of FORTUNE's 100 Best Companies to Work For
From: Phillips, George L CIV USARMY CESAW(USA)<George.L.Phi Ili [e-mail]>
Sent: Monday, March 23, 2020 2:36 PM
To: Richards, Mackenzie<[e-mail]>
2

Cc: Goss, Stephanie<[e-mail]>
Subject: Blue Ridge Road (SR 1670)Widening/SAW-2018-00496/Incomplete Application Notification
Mackenzie,
I have reviewed the PCN for the above referenced project, and I have a few comments/questions that need to be
addressed prior to proceeding with review and issuance of the permit verification. Please let me know if you have any
questions.
1) It appears that the upstream permanent stream channel impacts would include the section of stream from the
proposed banks graded to the proposed culvert to the start existing culvert downstream. Please update the PCN and
plans accordingly.
2) Please provide information on the proposed Permanent Impacts in Surface Water(Bank Stabilization) activity? For
example, what bank stabilization method is proposed?Will the proposed bank stabilization result in fill material being
placed below the OHWM?Will fill material be place within the stream bed?
3) It appears that the base for the pedestrian bridge is designed within the stream channel. Fill material below the
OHWM as currently designed would result in permanent stream channel loss. Please provide justification for why impact
could not be avoided. Please update the PCN and plans accordingly.
4) Please provide a profile view of the crossing shown along the proposed culvert.The profile should show the culvert,
rip rap pad (if proposed), slope and existing stream bed. Please note that regional condition 3.6.1 states that culverts
greater than 48 inches in diameter will be buried at least one foot below the existing bed of the stream. When using
more than one culvert, in order to comply with NWP 14 Regional Condition 3.6.2, one culvert should act as the low flow
pipe (invert buried 1' below the stream bed), and the other culverts should act as the high flow culvert(only to receiving
bank-full flows). High flow culverts are typically designed by placing its invert at bankfull level, or at least a foot or two
above the existing stream bed.Another way to comply with this condition it to design sills at the inlet and outlet of the
high flow culvert to only allow flow in the high flow culvert at the above referenced flow level. Additionally, in order to
comply with regional condition 3.6.5 the width of the culvert shall be comparable to the width of the stream channel. If
the width of the culvert is wider than the stream channel, the culvert shall include baffles, benches and/or sills to
maintain the width of the stream channel. A waiver for condition 3.6.5 may be requested in writing;this request must
be specific as to the reason(s)for the request.
5) Is rip rap proposed to be placed in the stream associated with the crossing? If so, include the rip rap on the plan and
profile view of the crossing, and ensure that the stream impacts associated with rip rap is included and itemized clearly
on the PCN and plans.
6) If rip rap is proposed, clearly note whether or not the rip rap in the stream bed will be keyed into the stream bed. If
above-grade rip rap is proposed on the stream bed due to needed velocity dissipation, clearly describe this in the PCN
and show on the plans; note that this would likely be considered a permanent impact and count towards the
compensatory mitigation threshold.
Please submit the requested information above within 30 days of receipt of this Notification, otherwise we may deny
verification of the use of the NWP or consider your application withdrawn and close the file.
G. Lyle Phillips
Regulatory Specialist
US Army Corps of Engineers
CE-SAW-RG-R
3331 Heritage Trade Drive, Suite 105
3

Wake Forest, North Carolina 27587
Phone: [phone], Ext. 25.
Fax: [phone]
Email: [e-mail]
4

Kimley>>> Horn
April 23, 2020
Mr. Lyle Phillips
U.S. Army Corps of Engineers
Raleigh Regulatory Field Office
3331 Heritage Trade Drive, Suite 105
Wake Forest, NC 27587
Mr. Rob Ridings
NCDWR, 401 & Buffer Permitting Unit
1617 Mail Service Center
Raleigh, NC 27699
RE: Blue Ridge Road(SR 1670) Widening
City of Raleigh, Wake County, North Carolina
USACE Request for Additional Information (SAW-2018-00496) &401 Permit Modification
(NCDWR#20200349)
Dear Mr. Phillips and Mr. Ridings,
On behalf of our client, the City of Raleigh, Kimley-Horn is submitting the enclosed additional
information for the above referenced project in response to the U.S. Army Corps of Engineers
(USACE)additional information request received on March 23, 2020. Additionally, the City of Raleigh
is requesting a modification to the previously approved General Water Quality Certification 4135 and
Buffer Authorization (NCDWR#20200349) due to changes in the utility design and easement
acquisition. Below is an explanation of the permit modification request as well as responses to the
USACE request for additional information.
401 Permit Modification Information
The 12"water line that was previously proposed to the south of Blue Ridge Road has been relocated
below Blue Ridge Road in order to reduce impacts to the Neuse River Riparian buffers of House
Creek and to reduce construction costs. It was previously thought that the House Creek culvert would
be an obstacle to running the waterline under the roadway; however, once the culvert design was
finalized, the necessary spacing to route the waterline below the road became available. As a result,
previously proposed buffer impacts resulting from the water line are no longer proposed as part of the
final design. Instead, these areas will now be used solely for temporary construction access and have
been changed in the attached tables to temporary impacts. This change has resulted in a reduction of
2,120 square feet of permanent zone 1 buffer impacts and 3,778 square feet of zone 2 buffer
impacts, and an increase of 2,861 square feet of temporary zone 1 buffer impacts and 2,650 square
feet of temporary zone 2 buffer impacts. As a result, the total mitigatable buffer impacts have been
reduced by 15,429 square feet to a new total of 49,626 square feet buffer impacts requiring mitigation

Kimley>>> Horn Page 2
USACE Request for Additional Information Comments and Replies
Below is an outline of the USACE comments with a brief narrative addressing each item. The
USACE comments with Kimley-Horn responses and explanations are as follows:
1) It appears that the upstream permanent stream channel impacts would include the section of
stream from the proposed banks graded to the proposed culvert to the start existing culvert
downstream. Please update the PCN and plans accordingly.
• The project proposes to temporarily impact the 43-foot section of House Creek (Site
2) located upstream of Blue Ridge Road between two areas proposed of bank
stabilization. The upstream bank stabilization site (Site 1)will consist of grading back
the bank and installing vegetative stabilization. The downstream bank stabilization
site (Site 2)will consist of armoring the banks with keyed-in rip rap at a culvert inlet.
The proposed bank grading will tie in to the existing streambank at the point where
temporary impacts are proposed. The 43-foot length of temporary impacts will be
used only for construction access and will be returned to pre-existing condition
following the completion of the project.
2) Please provide information on the proposed Permanent Impacts in Surface Water(Bank
Stabilization) activity?For example, what bank stabilization method is proposed? Will the
proposed bank stabilization result in fill material being placed below the OHWM? Will fill
material be place within the stream bed?
• There are two types of proposed streambank stabilization that would result in in
permanent stream impacts to House Creek. At the proposed culvert inlet and outlet
below Blue Ridge Road, Class II rip rap will be keyed-in to the banks only and not the
streambed. In the uppermost section of House Creek, the stream banks will be
graded back, and live stakes will be installed to create a more stable channel and
prevent erosion along the reach. The proposed streambank stabilization design
would result in permanent, no-net loss of water impacts or aquatic function to House
Creek.
3) It appears that the base for the pedestrian bridge is designed within the stream channel. Fill
material below the OHWM as currently designed would result in permanent stream channel
loss. Please provide justification for why impact could not be avoided. Please update the
PCN and plans accordingly.
• For hydraulic efficiency, the bridge was aligned as close to perpendicular to House
Creek as possible in this location. The House Creek banks below the proposed
pedestrian bridge will be armored with keyed-in rip rap to reduce the potential for
erosion and ensure long-term stability of the stream and the bridge in this location.
The proposed rip rap bank stabilization extends from the top of bank adjacent to the
bridge supports and to the toe of the channel. The geometry of the stream channel
and banks in this reach were designed to most closely match the upstream and
downstream sections and will result in no net loss of stream to House Creek.

Kim ey>>> Horn Page 3
4) Please provide a profile view of the crossing shown along the proposed culvert. The profile
should show the culvert, rip rap pad(if proposed), slope and existing stream bed. Please note
that regional condition 3.6.1 states that culverts greater than 48 inches in diameter will be
buried at least one foot below the existing bed of the stream. When using more than one
culvert, in order to comply with NWP 14 Regional Condition 3.6.2, one culvert should act as
the low flow pipe (invert buried 1'below the stream bed), and the other culverts should act as
the high flow culvert(only to receiving bank-full flows). High flow culverts are typically
designed by placing its invert at bankfull level, or at least a foot or two above the existing
stream bed. Another way to comply with this condition it to design sills at the inlet and outlet
of the high flow culvert to only allow flow in the high flow culvert at the above referenced flow
level. Additionally, in order to comply with regional condition 3.6.5 the width of the culvert
shall be comparable to the width of the stream channel. If the width of the culvert is wider
than the stream channel, the culvert shall include baffles, benches and/or sills to maintain the
width of the stream channel. A waiver for condition 3.6.5 may be requested in writing;this
request must be specific as to the reason(s) for the request.
• All three culvert barrels will be buried 1' below the stream bed. The project does not
have have a high flow barrel proposed. The proposed culvert was sized to meet the
hydraulic capacity needed to comply with NCDOT hydraulic design requirements and
FEMA requirements. The maximum NCDOT standard culvert spans were used to
meet this capacity, because a bridge was not determined to be feasible at this
location based on the existing roadway profile. NCDOT or FEMA requirements
cannot be met without utilizing the full capacity of the culverts, which would not be
possible if any of the barrels included a sill. Higher floodplain culverts were not
feasible because the roadway cover is minimal in this area. Enough capacity needed
to be provided so that the BFE would not be exceeded since there are structures in
the floodplain, so additional sill height was not feasible. Additionally, the pedestrian
culvert has been designed to provide some floodplain capacity for the higher storm
events (See CSR).
5) Is rip rap proposed to be placed in the stream associated with the crossing?If so, include the
rip rap on the plan and profile view of the crossing, and ensure that the stream impacts
associated with rip rap is included and itemized clearly on the PCN and plans.
• Rip rap will be keyed into the banks to stabilize the culvert inlet and outlet at the
crossing, which we included as part of the streambank stabilization impacts total.
There are two separate activities: (1) rip rap embedded along the banks including rip
rap below the OHWM but no rip rap being installed within the stream bed, and (2)
vegetated bank stabilization and grading along the banks and below the OHWM. As
discussed in a pre-application meeting with James Lastinger, it is Kimley-Horn's
understanding that both streambank stabilization activities are considered
permanent, no-net loss impacts. Installation of rip rap within the streambed as
dissipater pads above and below the culvert is not proposed for the project. The

Kim ey>>> Horn Page 4
culvert detail displaying the cross section and the countersunk rip rap is included as
part of this submission (See CSR).
6) If rip rap is proposed, clearly note whether or not the rip rap in the stream bed will be keyed
into the stream bed. If above-grade rip rap is proposed on the stream bed due to needed
velocity dissipation, clearly describe this in the PCN and show on the plans;note that this
would likely be considered a permanent impact and count towards the compensatory
mitigation threshold.
• The bank stabilization will be Class II rip rap keyed-in on the banks only. No rip rap
will be placed within the streambed. The proposed keyed-in rip rap is captured as
bank stabilization resulting in permanent, no-net loss impacts.
In addition to the above information, the following items have been included with this submittal:
• Updated Impact Tables from PCN
• Updated Permit Impact Drawings
• CSR
• Redline Drainage Plans
• Inlet Computation and Storm Drain Design Computation Sheets
If there is any additional information that you need to assist in the processing of this permit application
package, please do not hesitate to contact me at(919)678-4154.
Sincerely,
Kimley-Horn and Associates, Inc.
Mackenzie Richards
Attachments