20051608 Ver 1_Information Letter_20050314

Alfred B. Cunningham Bridge over Trent River - B-2532
Vince Rhea (DOT), N. Thomson (DWQ), Paul Barber (HNTB), Tracy Roberts (HNTB),
Anne Lenart-Redmond (HNTB)
In an email, explained to DOT that a State Stormwater permit would be required because
the project is in New Bern (one of 20 coastal counties). Pointed to the website for the
BMP manual for state stormwater and gave a contact (Bradley Bennet).
Further explained that it was the new impervious in the buffer zone that was triggering
the buffer rules and therefore, 30°Io nitrogen removal/reduction would have to be
demonstrated. Again, pointed to the stormwater BMP manual which has stormwater
design criteria that also remove nitrogen at 30%. There are design constraints because of
where the project is. Told DOT if they only widened the bridge and not the approaches,
they wouldn't trigger the buffer rules and therefore would be required to get the 30%
nitrogen removal.
With respect to questions raised by the consultants:
Is it just the first inch of storm water that needs to be treated or all of it? Design criteria
must be for the 10 year storm event at diffuse flow and non-errosive velocities through
the buffer otherwise, 30% nitrogen removal must be demonstrated through an acceptable
design (listed in the BMP)
For a swing span or bascule movable span, will it be necessary to catch stormwater from
the open joints? Yes, all stormwater must be captured and treated, even where there are
open joints. There shall be no direct discharge to the stream river.
Is open grating a possibility? No. See above.
Will an oil/water separator work? No, there will not be 30°Io nitrogen reduction.
Will a sand filter work? No, there will not be 30°Io nitrogen reduction.
What percentage of TSS (Total Suspended Solids) needs to be removed? Contact
Bradley Bennet's group; that is part of the state storm water permit.

imap://nicole.thomson%40dwq.denr.ncmail.net @ cros.ncmail.net: l43/f
Subject: RE: R-2532, Alfred B. Cunningham Bridge over Trent River
From: "Biddlecome, William J SAW" <[e-mail]>
Date: Mon, 14 Mar 2005 09:23:13 -0500
To: "Nicole Thomson" <[e-mail]>, "Travis Wilson"
<[e-mail]>, "Gary Jordan \(E-mail\)" <[e-mail]>
Nikki:
Mike B. had made the commitment or advised DOT (whatever you want to call it) that we could use a
Cat-Ex (nationwide #23) if the bridge was replaced in place. Of course if that's the way they proceed,
then the document will need to be sufficient or we won't process it under acat-ex. It's no different then
some of the ones we've received in the past. If we don't agree with the document or the impacts or other
issues are not covered sufficiently, we will advise DOT they need to apply for an I.P.
-----Original Message-----
From: Nicole Thomson [mailto:[e-mail]]
Sent: Wednesday, March 09, 2005 2:53 PM
To: Biddlecome, William J SAW; Travis Wilson; Gary Jordan (E-mail)
Subject: R-2532, Alfred B. Cunningham Bridge over Trent River
Hey guys
Ok, I had a meeting with Vince Rhea for this project today and we discussed stormwater
management issues. Basically, DOT and the Consultants were looking at me to design their
bridge. There was no Hydraulics Unit representative there. I explained to them that with the new
impervious in the Buffer, it triggers the buffer rules and therefore requires the treatment of
stormwater. Nevermind the fact that the location of the project will require a state stormwater
permit any way.
Now, having said all that, I need to bounce a few things off you all and see how you feel. I am
still believing, due to the nature of the project, that this should be in Merger and for the following
reasons. This is a replace in-place bridge project (which does make it eligible for Merger, even as
a Cat. Ex.) AND there are Buffer Rules, CAMA, Section 4(f)/Section 106 and the issue of SAV's.
The Merger O1 Process lists the above as reason enough to put a project in Merger. Failing that, I
would really REALLY like a meeting of the minds as it were with ALL of the necessary parties to
sit down and hash out what the potential issues are. I am just really uncomfortable with this
piece-meal approach by DOT.
Let me know how you all feel, ok?
Thanks !
Nikki
Nicole Thomson
Enviranmental Specialist III
1tiJC Qivision of Water Quality
Yranspartation Permitting Unit
2321 Crabtree Blvd., Suite 250
Raleigh, NC 276Q4-2260
Teiephone: (919} 715-3415
1 of 2 3/14/2005 1:46 PM

imap://[e-mail]:143/f...
Subject: RE: R-2532, Alfred B. Cunningham Bridge over Trent River
From: "Biddlecome, William J SAW" <[e-mail]>
Date: Mon, 14 Mar 2005 09:23:13 -0500
To: "Nicole Thomson" <[e-mail]>, "Travis Wilson"
<[e-mail]>, "Gary Jordan \(E-mail\)" <[e-mail]>
Nikki:
Mike B. had made the commitment or advised DOT (whatever you want to call it) that we could use a
Cat-Ex (nationwide #23) if the bridge was replaced in place. Of course if that's the way they proceed,
then the document will need to be sufficient or we won't process it under acat-ex. It's no different then
some of the ones we've received in the past. If we don't agree with the document or the impacts or other
issues are not covered sufficiently, we will advise DOT they need to apply for an I.P.
-----Original Message-----
From: Nicole Thomson [mailto:[e-mail]]
Sent: Wednesday, March 09, 2005 2:53 PM
To: Biddlecome, William J SAW; Travis Wilson; Gary Jordan (E-mail)
Subject: R-2532, Alfred B. Cunningham Bridge over Trent River
Hey guys
Ok, I had a meeting with Vince Rhea for this project today and we discussed stormwater
management issues. Basically, DOT and the Consultants were looking at me to design their
bridge. There was no Hydraulics Unit representative there. I explained to them that with the new
impervious in the Buffer, it triggers the buffer rules and therefore requires the treatment of
stormwater. Nevermind the fact that the location of the project will require a state stormwater
permit any way.
Now, having said all that, I need to bounce a few things off you all and see how you feel. I am
still believing, due to the nature of the project, that this should be in Merger and for the following
reasons. This is a replace in-place bridge project (which does make it eligible for Merger, even as
a Cat. Ex.) AND there are Buffer Rules, LAMA, Section 4(f)/Section 106 and the issue of SAV's.
The Merger O1 Process lists the above as reason enough to put a project in Merger. Failing that, I
would really REALLY like a meeting of the minds as it were with ALL of the necessary parties to
sit down and hash out what the potential issues are. I am just really uncomfortable with this
piece-meal approach by DOT.
Let me know how you all feel, ok?
Thanks !
Nikki
Nicole Thomson
environmental Specialist III
NC Division ofi Water C~uality
Transportation Permitting Unit
2321 Crabtree Blvd., Suite 250
Raleigh, NC 27604--2260
Telephone: [phone]
1 of 2 3/14/2005 1:47 PM

_, _
'= Tracy Roberts, AICP

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imap://[e-mail]:143/f...
Subject: RE: Trent River Bridge
From: "Wilson, Travis W." <[e-mail]>
Date: Tue, 1 Mar 2005 15:32:46 -0500
To: "'Nicole Thomson"' <[e-mail]>
CC: "Biddlecome, William J SAW" <[e-mail]>, "Gary Jordan
(E-mail)" <[e-mail]>
The issue of storm water and direct discharge was briefly mentioned. We stated DOT would have to coordinate
with DWQ on this issue, but they could assume they would not be able to directly discharge into the Trent River,
therefore they would have to capture the storm water and treat it adequately. DOT's consultant seemed to be
"taken aback" by this.
Finding a location for storm water basins will be difficult for DOT due to the nature of the land and development
around this bridge. This project has the potential to find its self in the same position as Sun Set Bridge. (ask John
about those issues)
-----Original Message-----
From: Nicole Thomson [mailto:[e-mail]]
Sent: Tuesday, March O1, 2005 3:14 PM
To: Biddlecome, William J SAW; Travis Wilson; Gary Jordan (E-mail)
Subject: Trent River Bridge
Hey Guys!
I am going to a meeting next week with DOT (and Vince Rhea) regarding stormwater issues on
the Trent River Bridge. I can only assume that this is the same meeting you had with Vince for
the channel relocation. I want to be sure that I am not going to get blindsided when I get to this
meeting. I already emailed Vince and politely asked if this was the same project that you all met
on previously (and I wasn't invited..sheesh!) and why he was scheduling a separate meeting with
me (under a different project name I would like to point out).
In any event, I want to be sure that I have all my ducks in a row when I get to this meeting AND I
want to make sure that all of your concerns are addressed (ie EFH, Endangered or Threatend
species, etc) and to make sure that I am not going to get sucked into agreeing to something that
you all DON'T agree to. I am also concerned since DOT hasn't really decided what they want to
yet with regards to this project, but I am being called in for stormwater issues. I know, paranoid,
but I don't want to get "played" again.
Thanks in advance...I'll catch next week at concurrence! (my meeting with Vince is the 9th
BTW)
CYA
Nikki
Nicole Thomson
Environmental Specialist III
NC Division of Water Quality
Transportation Permitting Unit
2321 Crabtree Blvd., Suite 250
Raleigh, NC 27604-2260
1 of 2 3/9/2005 4:37 PM

imap://[e-mail]:143/f
Subject: RE: TIP B-2532 Alfred Cunningham Bridge: Channel Relocation meeting with agencies
From: "Biddlecome, William J SAW" <[e-mail]>
Date: Tue, 1 Mar 2005 08:52:45 -0500
To: "Nicole Thomson" <[e-mail]>
Nikki:
The meeting basically explained where DOT was at this point and we discussed
all the environmental issues associated with proposed project with moving the
channel and without dredging a new channel. DOT basically had seven
alternatives on the table and wants to get down to 2-3 alternatives in the
near future. According to DOT (Vince Rhea), it appears unlikely they will
proceed with the alternatives that involve moving the channel. It appears
most likely they will proceed with replacing the bridge in place (Bascule
design or a lift elevator type bridge). From what I understand, the Bascule
is a design that one end or both ends of the bridge actually lift up from the
ends and the other is where the center portion of the bridge actually lifts
straight up. The reason they are looking at not putting this in the Merger
is that Mike Bell had basically told DOT that if they replaced the bridge in
place they could look at doing a Categorical Exclusion document and
permitting the project under a nationwide # 23. If something changes where
the project may require a IP then we would look at putting the project in the
Merger Process. DOT was going to get back with us after they have reviewed
all the information that was presented to them at the meeting and then decide
how they were going to proceed with the bridge replacement. Hope this helps!
Bill
-----Original Message-----
From: Nicole Thomson [mailto:[e-mail]]
Sent: Friday, February 25, 2005 3:23 PM
To: Wilson, Travis W.; Gary Jordan; Biddlecome, William J SAW
Subject: Re: TIP B-2532 Alfred Cunningham Bridge: Channel Relocation
meeting with agencies
Just curious as to what came out of this meeting?
Talk to ya later.
Nikki
,.'~]
1 of 1 3/1/2005 2:59 PM

North Carolina Department of Transportation
Project Development and Environmental Analysis Branch
Channel Relocation Technical Memorandum
TIP B-2532
Bridge No. 60 in Craven County
Alfred Cunningham Bridge on US70 Business over the Trent River
New Bern, North Carolina
I. BACKGROUND
HNTB North Carolina, P.C. has been employed as a consultant to NCDOT to prepare a Categorical Exclusion for
the existing Alfred Cunningham Bridge in New Bern, North Carolina. As part of this process, an investigation into
the feasibility of relocating the existing Trent River navigation channel will be performed. Relocating the channel
could provide structural and maritime advantages, as discussed later in this report.
The Alfred Cunningham Bridge, NCDOT Bridge 60 in Craven County, was designed in approximately 1953 and
constructed in 1955. The Cunningham Bridge is 1763 feet long with a 350 foot New Bern approach, a 220 foot
truss swing span, and an 1190 foot James City approach. Approaching 50 years in age, the Alfred Cunningham
Bridge is structurally deficient and functionally obsolete. Therefore, NCDOT is considering several alternatives
to address existing bridge deficiencies, including removing the bridge with no replacement, rehabilitating the
existing bridge and replacing the existing bridge with a new bridge or tunnel.
II. BRIDGE LOCATION
The Alfred Cunningham Bridge is located in the eastern, coastal region of North Carolina in Craven County. The
bridge provides a vital link across the mouth of the Trent River at its confluence with the Neuse River. Historic
downtown New Bern at the north end of the bridge terminus is connected to James City to the south via US70
Business (East Front Street). The Trent River flows eastward into the Neuse River which then flows southward
until reaching Pamlico Sound.

B-2532 -Bridge No. 60 Craven County
~~ Alfred Cunningham Bridge on US 70 Business over Trent River
Draft Channel Relocation Technical Memorandum
February 14, 2005
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III. EXISTING CHANNEL CHARACTERISTICS
Project
Location
The Trent River provides a navigable channel from the confluence with the Neuse River in New Bern to Trenton,
approximately 38 miles upstream. The channel gradually decreases in depth and width as it progresses upstream
due to river geometry. At the channel passage of the Cunningham Bridge site, the channel is a dedicated 300 feet
in width and 12 feet in depth (minimum) and extends from the Neuse River navigation channel to the existing
railroad swing bridge owned by North Carolina Railroad and leased for operations by Norfolk Southern (see
Figure 2). The Trent River channel decreases in size west of the railroad bridge to 6 feet in depth to Foys Flats, a
distance of about 6 miles. From Foys Flats to Trenton, the channel is 50 feet wide and 4 feet in depth. It should
be noted that the Trent River channel above the railroad bridge was decommissioned in August of 1977. The
following definitions should be noted when considering navigational clearances due to the varying water
elevations of rivers and their effects on vertical clearances.
- Mean Higher High Water (MHHW): The average height of the higher high waters fora 19 year period.
The MHHW elevation for the Cunningham Bridge site is taken as 3.49 feet.
- Mean High Water (MHW): The average height of the high waters over a 19 year period. The MHW
elevation for the Cunningham Bridge site is taken as 3.22 feet.
- Mean Tide Level (MTL): A plane midway between MHW and MLW. This elevation is not necessarily
equal to mean sea level. The MTL elevation for the Cunningham Bridge site is taken as 1.68 feet.
- Mean Low Water (MLW): The average height of the low waters over a 19 year period. The MLW
elevation for the Cunningham Bridge site is taken as 0.14 feet.
1

B-2532 -Bridge No. 60 Craven County
^ ~ Alfred Cunningham Bridge on US 70 Business over Trent River
Draft Channel Relocation Technical Memorandum
February 14, 2005
- Mean Lower Low Water (MLLW): The average height of the lower low waters fora 19 year period. The
MLLW elevation is the baseline elevation for the soundings and for the Cunningham Bridge site is taken
as 0.00 feet.
Note: The bench mark designated K 103 elevations relating to MLLW are as follows:
North American Vertical Datum of 1988 (NAND 88): A vertical network defined by 1 station,
Father Point/Rimouski, which is an International Great Lakes Datum (IGLD) water-level
station located at the mouth of the St. Lawrence River in Quebec, Canada. Bench Mark K103,
elevation 2.11 feet.
National Geodetic Vertical Datum of 1929 (NGVD 29): A fixed reference based upon mean sea
level adopted as a standard geodetic datum for elevations determined by leveling, established
in 1929. The NGVD is usually preferred as the primary datum for engineering design. Bench
Mark K103, elevation 1.15 feet.
Vertical and horizontal clearances above navigable waters to obstructions are traditionally measured from Mean
High Water (MHW). However, the depth of the channel is measured from Mean Low Water (MLW) or referred
to as "dead low water" in US Army Corps of Engineers documents. This permits boaters under ordinary
circumstances to navigate through the stated passage provided on navigable charts. The difference between
MHW and MLW at the Cunningham site is approximately 3.08 feet. In addition, the Trent River channel is
considered non-tidal with variations in water elevation of 2-3 feet due to winds.
The navigational channel generally appears to be a stable waterway based upon the fact that very little dredging
has occurred to maintain the dedicated waterway. The US Army Corps of Engineers (USAGE) stated the
channel was last dredged in 1942, requiring the removal of 12,150 cubic yards of sediment. This yardage
indicates an average excavation of approximately 0.5 feet for the 2125 foot long, 300 foot wide channel.
However, as part of this project, soundings were performed east of the Cunningham Bridge to supplement
soundings already received from the USAGE west of the bridge. All sounding information is based upon mean
low water as the elevation 0.0 datum. Soundings indicate the current channel depths to vary from approximately
7.5 feet along the northern edge of the channel on the east side to 13.5 feet at the center of the southern channel
at the bridge (see Figure 3). The U.S. Department of Commerce, National Oceanic and Atmospheric
Administration (NOAA) map shows the navigable depth of the channel at 7 feet.
The dedicated navigational channel was restricted in size by the construction of the Alfred Cunningham Bridge
in 1955. The bridge information indicates the centerline of the pivot pier for the swingspan aligns with the
centerline of the dedicated navigation channel. The piers and fender system for the crossing were placed at an
eight degree skew from the normal (an 82 degree bridge skew as measured by NCDOT) to match the
navigational channel. The swingspan operation permits two, 78 foot clear width waterways between fenders
when open with unlimited vertical clearance (see Figure 4). The center of the channel is located approximately
460 feet south from the New Bern end of the bridge, and 1300 feet from the James City end of the bridge. In the
closed position, approximately 14 feet of vertical clearance is provided from mean high water.
The dedicated navigational channel has been further restricted with the presence of the Sheraton Marina
associated with the Sheraton Hotel on the New Bern shore. The geometry and impacts are later discussed under
Section IV -Marina Geometry.

B-2532 -Bridge No. 60 Craven County
H~ Alfred Cunningham Bridge on US 70 Business over Trent River
Draft Channel Relocation Technical Memorandum
February 14, 2005
IV. EXISTING MARINA GEOMETRY
The Trent River area just west of the Alfred Cunningham Bridge is occupied by two marinas (see Figure 5). The
northern, New Bern side of the Trent has been developed by the Sheraton Corporation in association with a hotel
and provides slips for a total of approximately 250 boats on six separate piers. An expansion of the marina was
just completed in October of 2004. The James City side, the southern side, has been developed into the Bridge
Pointe Hotel & Marina in association with the hotel and provides slips for a total of approximately 125 boats on
three separate piers. Both marinas were contacted and information was gathered for this report.
The Sheraton Marina is shaped in a triangular form with the longest pier (the hypotenuse of the triangle)
geometrically placed to channel the boats towards the swingspan of the adjacent railroad bridge. The marina is
situated in the 300 foot dedicated channel, at least in part. The USACE Navigation Branch was unaware of this
encroachment until coordination for this report. The pier is located approximately 570 feet from the channel
intersection with the Cunningham Bridge, thus terminating the dedicated channel approximately 950 feet prior to
the original terminus. With the recent development of the New Bern shoreline from industrial/manufacturing to
residential and light commercial, the apparent commerce need for the dedicated channel may be lessened. The
longest pier (700 feet in length) extends approximately 500 feet from its intersection with the channel centerline.
The deflection angle of the channel is approximately 139 degrees. The slips typically berth about 600 transient
boats a year while the majority of the marina is composed of resident spaces. The vast majority of transient
boats journey from the Intracoastal waterway. The marina does serve as the base for Hatteras Yachts, located
approximately 4 miles upstream on the Neuse River. The marina provides a drop off point for new yacht and
service transfers. The largest boat that has docked in recent years was a 200 foot long cruise boat of
approximately 55 to 65 feet in width and a nine foot draft. Routinely,-135 foot long Hatteras boats are the largest
boats in port. Boat and mast heights of 64 feet are the maximum and may currently navigate the Neuse River at
the US70 bridge. Rarely, a construction barge for pier or other marine work has used the channel as a means of
egress up the Trent. The marina supervisor recommended that any restrictions on the channel imposed by new
bridge construction permit clearances consistent with the downstream Neuse River bridge and the Intracoastal
waterway. Current vertical clearance of 14 feet to the closed span is sufficient, however, consideration should be
given to increasing the clearance to 16 feet to permit a greater number of power boats to pass.
The Bridge Pointe Marina provides three finger docks that are parallel to the bridge alignment. The docks are
approximately 550 feet in length. The distance from the center of the existing Cunningham swingspan to the end
of the dock is approximately 725 feet. The extreme corner of the dock provides an opening of approximately
400 feet as measured perpendicular to the Sheraton dock. The marina is also directly in line with the
navigational channel passing through the railroad swing span requiring boaters to perform a sharp turn to avoid
the dock or navigate the clear channel afforded them. The deflection angle is approximately 112 degrees.
Generally, smaller boats than at the Sheraton occupy the slips. Sail boats with 7 foot draft and maximum vertical
clearance of 64 feet are present. A number of power boats with fly bridges and helm stations are resident. The
marina supervisor indicated similar thoughts on the clearance requirements as the Sheraton supervisor.
However, because of the higher number of power boats in residence, an increased clearance of 16 feet or 18 feet
was recommended in the closed position to permit passage of the fly bridge equipped boats.

~~~ B-2532 -Bridge No. 60 Craven County
Alfred Cunningham Bridge on US 70 Business over Trent River
Draft Channel Relocation Technical Memorandum
February 14, 2005
V. MINIMUM CHANNEL REQUIRMENTS; COSTS; DURATION; PROCEDURE FOR REQUESTING
CHANGE
Minimum channel requirements
On January 19`h, 2005, representatives from HNTB and NCDOT met with officials from the USACE in
Wilmington, North Carolina to discuss the requirements and procedure for relocating the existing Trent River
navigational channel. According to discussions held during that meeting, the new channel would need to be
consistent with the original channel dimensions as authorized in 1927, which include a 300 foot channel width
and a 12 foot channel depth (below mean low water). Additionally, the new channel depth would need to be
dredged 2 feet below the authorized depth of 12 feet. Officials with the USACE Navigation Branch indicated
that they would not object in principle with relocating the channel, provided all other permitting and
environmental requirements were met. Based upon discussions with USACE and the local marinas, a 65 foot
vertical clearance for fixed span alternatives is recommended along with a minimum horizontal channel width of
90 feet (see Figure 6). For movable span alternatives, a 14 foot minimum vertical clearance to the closed span
must be provided.
Costs
The costs associated with channel relocation would differ depending on a number of variables, such as soil type,
presence of rock, the location of the disposal area and the necessity for utility relocations. As an example, the
USACE indicated that the Manteo dredging project cost $6 per cubic yard, but cautioned that this cost could vary
depending on local soil conditions and other factors.
According to the USACE, limiting the disposal area for the dredged material to within five miles of the dredging
site would serve to minimize costs.
The USACE staff indicated that construction of the new channel would need to be funded by someone other than
the USACE. Also, since the channel was last dredged in 1942, the USACE has not had to spend funds on
channel maintenance. Thus, the USACE may seek financial assistance from NCDOT for channel maintenance.
Duration
The length of time to dredge is dependent on a number of variables and is difficult to predict. Although the
USACE could not state with certainty how long it would take to complete dredging operations, they were able to
provide some guidelines. For example, the size of the dredge line can determine how much material can be
dredged per day. A 12 inch dredge line can move 3,000 yd3 per day while an 18 inch dredge line can move
5,000 yd3 per day. If the river bottom is muddy, the quantities of dredged material can increase.
Procedure for requesting change
According to USACE, a specific procedure is in place to request changes to existing navigational channels. For
the Alfred Cunningham Bridge, NCDOT would need to submit a written request to the USACE Wilmington
District. NCDOT would also need to secure the approval of Craven County to serve as the local sponsor. The
letter from NCDOT would also need to include a discussion of the various alternatives being considered.
Following a 1-2 day in-house review, the request would be forwarded to the Corps' District Engineer. After a

B-2532 -Bridge No. 60 Craven County
Alfred Cunningham Bridge on US 70 Business over Trent River
Draft Channel Relocation Technical Memorandum
February 14, 2005
review by the District Engineer, the request would be sent to Corps Headquarters in Washington DC for a final
decision. According to the USACE, this process could take up to six months to complete.
According to discussions with the US Coast Guard (USCG), the issue of channel relocation is predominately
within the control of the USACE. The USCG is chiefly interested in the bridge clearances over the portion of the
navigable channel that passes underneath the bridge. The channel approaches would be left to the jurisdiction of
the USACE. To initiate the preliminary public notice process, the USCG would need to know existing and
proposed bridge clearances over the navigable channel, as well as be provided with copies of bridge tender logs
and information on the types of vessels that use the bridge. The proposed fender system would also need to be
provided. Following a thirty day public notice period, the USCG would approve the clearances proposed by
NCDOT provided there are no conflicts with maritime users. A final public notice, including a Local Notice to
Mariners, would then be issued by the USCG to inform river users of the approved bridge clearances.
NOTE: Waiting to hear from USACE on specific submittal requirements. This information will be added in the
next draft memo.
VI. POTENTIAL ENVIRONMENTAL ISSUES
Relocating the Trent River navigational channel would require coordination with various State and Federal
environmental agencies, including the US Fish & Wildlife Service, National Marine Fisheries Service and the
North Carolina Department of Environment and Natural Resources. Potential environmental issues associated
with dredging could include impacts on the following:
-Threatened and endangered species, such as West Indian Manatee and Leatherback Sea Turtle
-Submerged aquatic vegetation
-Essential fish habitat
-Jurisdictional areas
-303(d) listed water bodies
-hazardous materials
A suitable upland disposal area would also need to be located. The USACE stated that there was no existing
upland disposal area that could be used. Environmental impacts associated with the storage and placement of
dredged material would need to be evaluated.
Compliance with the Coastal Area Management Act (CAMA) rules and policies would be necessary and a
CAMA permit would likely be needed.
NOTE: A meeting with various environmental agencies is pending. This section of the memo will be updated to
reflect the results of this meeting.
VII. ADVANTAGES AND DISADVANTAGES OF RELOCATING CHANNEL
There are distinct advantages for relocating the channel southward along the current alignment of the Alfred
Cunningham Bridge. Certainly, a number of the proposed seven alternatives are enhanced by the prospect while
others alternatives would not benefit or only slightly benefit from a relocation.

B-2532 -Bridge No. 60 Craven County
Alfred Cunningham Bridge on US 70 Business over Trent River
Draft Channel Relocation Technical Memorandum
February 14, 2005
The current bridge geometry consists of a 1,760 foot long crossing with the centerline of the 220 swingspan
located approximately 460 feet south of New Bern and 1,300 feet north of James City. As a result of the current
channel location, a 3 percent grade is used from the New Bern land elevation to raise the span. After a 0 percent
grade on the movable span, the bridge profile transitions to a 0.6 percent downward grade to the James City
landfall. The roadway elevation at the intersection of Front Street in New Bern is approximately 4.63 feet while
the roadway elevation at the intersection with the US70 exit ramp at the James City side is approximately 10.00
feet. Ideally, to maximize the vertical clearance, the channel should be located at a point using the maximum
permissible grade from both control points on shore. Due to the presence of the Bridge Pointe Marina, a
southward parallel shift of approximately 435 feet can be obtained (see Figure 7). The close proximity of Union
Point Park and the New Bern Riverfront Convention Center precludes the increased distance to toe of fill
location necessitated by higher land elevations. Certainly, retaining walls or an increased structure length may
minimize fill slope increases but not without other ramifications.
In addition to permitting an increase in the vertical clearance over the channel without landside effects, it appears
a slight improvement in the navigable channel will also occur. Relocating the channel southward will increase
the distance from the bridge site to the Sheraton Marina pier thereby decreasing the collision risk and increasing
the area to make the turn. Conversely, however, entrance by boats into the piers at the Bridge Pointe Marina may
be made more difficult by the reduced proximity.
There are potential disadvantages of channel relocation. To provide a 12 foot deep channel will require
dredging. The initial cost of the dredging, the potential for periodic maintenance dredging, coupled with the
inherent risks in dredging are certainly a monetary consideration along with potential adverse effects to the
environment as discussed previously. Relocation of any submarine utilities may also need to be addressed.
Recently, a submarine power line was installed in the bridge vicinity.
In summary, the alternatives which benefit the most from a relocated channel are those alternatives where
achieving maximum vertical clearance at the channel are a critical issue. Therefore, the fixed span alternative
and tunnel alternative benefit the most. Obviously, the removal and rehabilitation alternative would not benefit
by a channel relocation and this would not be requested. Movable alternatives would benefit slightly by
permitting increased clearances to the operating machinery from potential high water and to boaters where the
vertical clearance to movable spans in the closed position may be increased from the existing. The fixed span
alignment which curves into the Neuse River from the existing bridge end in James City and lands in New Bern
beyond Union Point Park ("fish hook alignment") has not progressed enough to make a determination of benefit.
VIII. SUMMARY
The existing dedicated channel passing the Alfred Cunningham Bridge was located to provide commerce from
the downtown area of New Bern in 1927. The 1955 construction of the bridge preserved the channel location at
minimal consequence to the surrounding downtown properties. With the growth of New Bern, Union Point Park
was created along with the commercial development of the areas surrounding the bridge. These properties were
constructed based upon the existing vertical profile of the bridge and would be impacted by a severe change in
profile now. To limit this impact and update the navigable channel to current users, a relocation of the channel
southward appears to be achievable. Certain alternatives being investigated will benefit from the realignment
more than others as discussed herein. Certainly, channel relocation will involve additional coordination and cost
associated with the project and may indeed involve environmental impacts.