20091224 Ver 1_Meeting Minutes_20080618

DRAFT MINUTES OF THE INTERAGENCY HYDRAULIC DESIGN MEETING
FOR B-3611, BEAUFORT CO.
JUNE 18, 2008

Team Members: William Wescott, USACE (PRESENT VIA TELEPHONE)
Gary Jordan, USFWS (PRESENT)
Travis Wilson, NCWRC (PRESENT)
David Wainwright, NCDWQ (PRESENT)
Kathy Matthews, EPA (PRESENT)
Donnie Brew, FHWA
Steve Sollod, NCDCM (PRESENT)
Stephen Lane, NCDCM
David Harris, NCDOT Roadside Environmental Unit
Jimmy Goodnight, NCDOT Roadway
Mack Bailey, NCDOT Structure Design Unit (PRESENT)
John Williams, NCDOT PDEA
Chris Rivenbark, NCDOT PDEA-NEU (PRESENT)
Ed Eatmon, NCDOT Division 2
Eddie Bunn, NCDOT Construction Unit (PRESENT)
Jay Twisdale, NCDOT Hydraulics (PRESENT)

Participants: Paul Atkinson, NCDOT Hydraulics (PRESENT)
Brook Anderson, NCDOT Hydraulics (PRESENT)
Dustin Creech, NCDOT Hydraulics (PRESENT)
Jiles Harrell, NCDOT Hydraulics (PRESENT)
Chris Underwood, NCDOT NEU (PRESENT)
David E. Bailey, NCDOT NEU (PRESENT)
Worth Calfee, NCDOT NEU (PRESENT)
Leilani Paugh, NCDOT NEU-ICI (PRESENT)
Bill Goodwin, NCDOT PDEA-Bridge Unit (PRESENT)
Natalie Lockhart, NCDOT PDEA-Bridge Unit (PRESENT)
Jon Loughry, NCDOT Roadway (PRESENT)
Steve Champion, NCDOT Structure Design Unit (PRESENT)
Ron Lucas, FHWA (PRESENT)

Jay Twisdale began the meeting with a brief overview of the project. He stated this
project consists of a bridge replacement project on NC 99 between SR 1778 and
US 264 BUS. (Main St.). The project is located in the Tar-Pamlico River Basin where
riparian buffer zones are required. The existing bridge of 1400 ft. in length will be
replaced with a 3352 ft. long prestressed concrete girder bridge. An on-site detour
utilizing the existing bridge will convey traffic during construction. Surface drainage on
the bridge will be collected primarily through closed deck drain systems and discharged
at the bridge ends. Jay went through the plans sheet by sheet, discussing the drainage
layout with emphasis on any impacts to affected wetlands or public trust waters. Specific
comments are listed below by plan sheet number:

Page 1 of 4

Sheet 4: Jay Twisdale stated that fill slopes throughout the project are 3:1 or flatter. The
proposed fill slope on the north side of the alignment from -L- Sta. 11+50 to 16+75(LT)
will partially impact a portion of tidal canal which is classified as a public trust area. Jay
indicated that the 404 wetlands along the south side of the alignment within this station
range would be unaffected. Kathy Matthews inquired about potentially steepening the
fill slopes to 2:1 along the north side of the alignment provided there would not be
stability issues in doing so. Steve Sollod seconded the request to steepen the north side
fill slope if allowed by the Geotechnical Unit and requested that the amount of impacts be
reduced as much as possible. Jay Twisdale indicated that such a request to the
Geotechnical Unit had not been formally made as of yet. Steve Sollod added that the
desired design scenario would limit the fill slope to intruding no more than 5 ft. into the
public trust area. This distance would be measured perpendicularly from the normal high
water line 5 ft. into the public trust area. Steve Sollod then requested a quantified amount
of impacts to the coastal wetland fringe. Jay indicated that the horizontal alignment had
been shifted as far South as possible to avoid more sizable impacts to the tidal canal and
the CAMA wetland region just north of the public trust area. Chris Rivenbark concurred
Jay's comment. Jay stated that the Hydraulics Unit would coordinate with the
Geotechnical Unit to verify if the fill slopes could be steepened within the station range
mentioned. In addition, Jay stated that the quantity of impacts to the public trust area in
discussion will be calculated. Paul Atkinson stated that steepening the fill slopes to 2:1
with rock lining in areas of shallow fill may not reduce impacts due to the additional
thickness of the rock lining which is additive to the footprint of the proposed fill slope.

In areas of alignment shift, the existing asphalt will be removed. Kathy Matthews
inquired about potential wetland restoration along the old roadbed. Leilani Paugh
indicated that significant restoration is undesirable due to invasive phragmite weed
infestation. Leilani added that the area would not have the qualities of a good wetland
partly because it would be a small strip located between the proposed roadway and the
tidal canal. William Wescott suggested that the Department of Transportation may want
to use this area of abandoned roadway as a treatment area for pavement runoff. Jay
Twisdale added that the proposed hydraulic design on the next sheet would utilize the
existing roadbed for that purpose. Leilani added that this is another reason not to pursue
wetland reclamation along the abandoned roadway alignment.

Sheet 5: The proposed design utilizes the existing bridge as an on-site detour while
construction of the new bridge will take place just north of the existing site. An on-site
temporary detour around the proposed bridge tie-in will begin at -L- Sta. 20+60 and run
on the east side prior to tying back to the roadway at approximate -L- Sta. 35+00. The
proposed hydraulic design is to allow the temporary detour fill to temporarily fill in a
portion of roadside canal. Consequently, the water in the roadside canal will temporarily
head up into the 404 wetlands south of the project. After traffic is shifted onto the
proposed alignment, the detour would be removed and the roadside canal would be
replaced on the south side of the proposed alignment. Team members did not have any
concerns with the proposed design.

Page 2 of 4

Jay Twisdale stated that a closed deck drain system would be used from the bridge crest
to the second interior bent at the beginning of the bridge. The closed deck drain system
would discharge into a proposed grassed Swale located on the former roadbed where the
existing pavement is to be removed. The proposed grassed swale would serve to treat
and convey the discharged waters toward Pantego Creek where the grassed Swale will
end in the ground prior to the limits of causeway removal, allowing the flow to head up
and discharge as sheet flow into the canals and creek. David Wainwright requested that
the grassed swale be as long as possible to adequately treat the waters discharged from
the bridge. In the first two bridge spans, open deck drains would discharge surface
drainage onto the former roadbed where the existing pavement is called to be removed
and the old roadbed scarified. Steve Sollod inquired if the discharge from the open deck
drains in the first two spans would create erosive velocities. Paul Atkinson indicated that
the vertical drop would be approximately 3 ft. and should not create an erosive situation.
Jay Twisdale added that this is the best design given the situation.

Sheet 6: The proposed design removes approximately 320 ft. of existing causeway from
approximately -L- Sta. 37+50 to Sta. 40+70 and would restore the natural channel
matching surrounding bathymetric elevations. Jay Twisdale requested that mitigation
credit be given for the causeway removal. Both Leilani Paugh and Chris Rivenbark
stated that mitigation credit could not be given for alteration involving surface waters.

Steve Sollod inquired about the bents in the left side canal potentially obstructing
navigability of canal. Mack Bailey stated that the design will call for a minimum of 6 ft.
horizontal clearance between the columns to allow for canoeist to navigate unobstructed.

Sheets 7&8: The proposed design removes approximately 390 ft. of causeway from
approximately -L- Sta. 54+40 to Sta. 58+30. Steve Sollod commented that this is a
significant amount of work to excavate the existing causeways down to match the
surrounding bathymetric elevations of the natural channel. Steve Sollod proposed that it
may be better to excavate to a marsh elevation. Travis Wilson requested that if the
causeway is to be removed that the channel be restored as closely as possible to a pre-
causeway state. William Wescott stated that it would be preferable to remove the
causeway to a pre-causeway state to restore maritime navigability of the channel. Eddie
Bunn concurred with William's comment.

Surface drainage will be collected in a closed deck drain system from the bridge crest to
the second to the last interior bent. The proposed design will discharge collected
drainage to the existing roadway alignment where the existing pavement is called to be
removed and the remaining ground to be scarified. A grassed swale will then treat the
system drainage and convey the water to approximately -L- Sta. 62+35(RT) before
combining with tidal canal waters. A grated inlet near the end of the bridge will pick up
any additional surface drainage and discharge into the grassed swale for treatment. Jay
Twisdale added that there were no other viable options for treatment due to site
constraints.

Page 3 of 4

The proposed design at approximately -L- Sta. 60+00 to Sta. 63+00 will fill in the
entrance of an existing canal north of the existing alignment. Jay Twisdale stated that the
canal would be relocated immediately north of the proposed alignment to maintain
connectivity with the remainder of the existing canal. Paul Atkinson stated that the
extent of the impacts resulting from the canal relocation work would be kept to a
minimum. In response to William Wescott's questions, Jay confirmed that the canal
would be relocated to the left (or west) side. Steve Sollod inquired about the extent of
impacts to the patches of CAMA wetlands bordering the existing canal. Jay Twisdale
indicated that the CAMA wetland at -L- Sta. 60+00(LT) would be significantly impacted
by the proposed fill slope and canal relocation. Steve Sollod requested that the fill slope
from -L- Sta. 62+00 to 63+00(LT) be pulled in as much as possible. Jay indicated that
the fill slopes shown on the plans from -L- Sta. 62+60 to 70+25(LT) are subject to
change following updates from Location & Surveys underwater bed shots of the existing
canal. In response to Steve Sollod's question, Jay indicated that the proposed base width
of the relocated canal may be around 5 ft. and that the existing canal base width was
approximately 8 ft. Paul Atkinson reiterated that a minimal design would be specified to
restore existing drainage patterns. Steve Sollod then asked if the canal was classified as a

public trust area. William Wescott stated that it was not.

Mack Bailey inquired if deck drains would be used in the last two bridge spans since the
closed deck drain system terminated at the second to the last interior bent. Paul Atkinson
and Jay Twisdale indicated that the surface drainage collected from the final two bridge
spans will be conveyed without deck drains in the bridge shoulder to the end of the
bridge. Jay added that the trunk line for the closed deck drain system from the crest to
the end of the bridge will be located on the right side of the alignment and that the trunk
line for the deck drain system from the crest to the beginning of the bridge will be located
along the left side of the bridge.

General Discussion: At the conclusion of the interagency meeting, there was some
discussion in regards to marine fisheries and deadlines to have required paperwork
submitted.

Travis Wilson stated that a moratorium on the project would be in effect from Feb. 15th
to June 15th.

A team member inquired about the navigational clearance of the bridge. The proposed
low chord of the new bridge is approximately 3.5 ft. higher than the existing.

Meeting adjourned with no further comments.

Page 4 of 4