20170257 Ver 1_1 B-5556 Permit App Cover Letter_20170306

Dewberry°
March 2, 2017
Raleigh Regulatory Field Office
US Army Corps of Engineers
3331 Heritage Trade Drive, Suite 105
Wake Forest, North Carolina 27587
ATTN: Mr. Eric Alsmeyer
NCDOT Coordinator
�ewberry Engineers Inc. 919.881.9939
261Q Wycliff Road, Suite 410 I 919.881.9923 fax
Raleigh, NC 276D7 www.dewberry.com
NC Division of Water Resources
512 North Salisbury Street
Raleigh, North Carolina 27604
ATTN: Mr. Rob Ridings,
Transportation Coordinator
Subject: Application for Section 404 Nationwide Permit 12, Section 401 Water Quality
Certification and Neuse River Riparian Buffer Authorization for the Proposed
Replacement of Bridge No. 910490 over Walnut Creek on Lake Dam Road in Wake
County, North Carolina; TIP No. B-5556; Federal Aid Project No. BRSTP-0520(53).
Dear Sirs,
The City of Raleigh (City) proposes to replace the existing 90-foot, two-span Bridge No. 910490 with a
100-foot, single-span bridge on existing alignment. Traffic will be maintained on an offsite detour that
has been utilized since the bridge was closed in 2014. Adjacent properties include a City-owned Walnut
Creek Greenway, which crosses the project south of Walnut Creek and a City-owned Lake Johnson Park
to the west.
Please see enclosed copies of the Pre-Construction Notification (PCN), stormwater management plan,
permit drawings, draft Natural Resources Technical Report (NRTR), and SHPO Section 106 Concurrence
letter. The Programmatic Categorical Exclusion (PCE) is being finalized. Final copies of the PCE and NRTR
will be forwarded as soon as they are available. A check for the NC DWR permit processing fee has been
submitted under separate cover (copy attached).
Jurisdictional Impacts
There will be 0.07 acre (107 feet) of temporary impact to Walnut Creek due to temporary dewatering
for utility relocation. Riparian buffer impacts will also result from utility relocation and slight
adjustments to the Greenway that crosses Lake Dam Road. Buffer impacts will total 3,400 square feet in
Zone 1 and 3,896 square feet in Zone 2. All impacts to riparian buffers are considered allowable as
Greenway impacts and impacts due to protection of existing structures.
Purpose and Need
Timber components of Bridge No. 910490 are deteriorating and can no longer be addressed by
reasonable maintenance activities; therefore, the bridge has reached the end of its useful life. The
bridge was closed in 2014 following a routine inspection, which revealed two beams in one span were
showing signs of failure. Replacement of the bridge will result in safer traffic operation.
Page 1 of 3

Lake Dam Road Bridge Replacement B-5556
Wake County
March 2. 2017
Brid�e Replacement
The bridge will be replaced on the same alignment with a cored slab bridge at approximately the same
elevation. Top down construction method will be utilized avoiding the need for a temporary work bridge
or work pad. The existing bridge and all components will be removed without fill in the creek. In order
to meet the new elevation of the road, it will be necessary to elevate the Greenway, which crosses Lake
Dam Road south of Walnut Creek.
Utility Relocations
The project also includes relocation of the following existing utility lines: 12-inch water line, 30-inch
sanitary sewer line, 6-inch natural gas line, and overhead electric lines. The electric lines will be
relocated without impacts to the stream or the riparian buffers. The water and natural gas lines will be
relocated underneath Walnut Creek using a coffer dam and pump around system. Every effort will be
made to coordinate the water and gas relocations under a single dewatering operation. However, if it is
not feasible, the area effected will be stabilized and re-vegetated immediately after each dewatering
operation. Please reference the attached Stormwater Management Plan for additional avoidance and
minimization efforts with these relocations.
Sewer Relocation — alternatives analvsis:
Sewer line relocation is required due to a conflict between the new bridge bent and the existing
manhole in Lake Dam Road on the north side of Walnut Creek. Relocation of the manhole necessitates
relocation of a portion of the sewer line east of the road. Several alternatives were analyzed in an effort
to minimize impacts to the riparian buffers and determine that there is no other practical alternative to
the current proposed design.
• Relocating the new sewer pipe/sewer easement outside of the Neuse River Buffer is not
possible without affecting the adjacent "University Commons" property. The sewer pipe and
sewer easement is currently on City-owned property.
• A gas main and overhead power are being relocated as well. The gas main and overhead electric
lines share the same corridor as the sewer main and further limit the possibility of re-angling the
sewer in order to move the sewer pipe out of the riparian buffer zone.
• Finally, in order to move the entire section of sewer out of the riparian buffer zone, it would be
necessary to relocate approximately 1,500 linear feet of reinforced concrete pipe sewer line,
which is downstream (east) from the bridge. It is cost prohibitive to relocate this length of sewer
line out of the buffer during this bridge replacement project.
Let Date
Lake Dam Road in the vicinity of this bridge has been closed to vehicular traffic since 2014. High priority
has been placed on replacing the bridge. Therefore, the project will be let for construction as soon as
possible following permit issuance.
Regulatory Approvals
Section 404 Permit: We anticipate that the utility relocations necessary for the bridge replacement and
approach work will be authorized under Section 404 Nationwide Permit 12.
Dewberry� Page 2 of 3

Lake Dam Road Bridge Replacement B-5556
Wake County
March 2. 2017
Section 401 Certification and Riparian Buffer Authorization: We anticipate 401 Water Quality
Certification 3884 will apply to this project. It is also anticipated that a Neuse River Riparian Buffer
Authorization will be issued for this project. We request written concurrence from the North Carolina
Department of Environmental Quality, Division of Water Resources.
Dewberry Engineers Inc. is an agent for the City of Raleigh, applying for permits on their behalf (see
attached agent authorization form). Therefore, we request that permits be issued to the City of Raleigh.
Please contact Elizabeth Lusk at [phone] or [e-mail] with any questions on this
application. Should you wish to speak with the City of Raleigh about this project, please contact Gilles
Bellot, Project Manager, at [phone] or Gilles.Bellot@ralei�hnc.�ov.
Sincerely,
''� / � /�,,
�
Mark Pearson, PE
Dewberry Project Manager
cc:
Gilles Bellot, PE, City of Raleigh
Chris Johnson, PE, City of Raleigh
Elizabeth Lusk, Dewberry
Attachments:
Pre-Construction Notification
Stormwater Management Plan
Permit Drawings
Natural Resources Technical Report
SHPO Section 106 Concurrence letter
Copy of Permit processing fee check
Agent Authorization Form
Dewberry` Page 3 of 3