Memo-11-13-2018-Item-12

November 13, 2018

MEMO TO:        Mayor Barber and Board of Commissioners

FROM:             Frank A. Rush, Jr., Town Manager

SUBJECT:       (Archers Creek) Lee Avenue Culvert Replacement - (Summary & Suggested Motions)

The Board of Commissioners is scheduled to consider two actions to initiate a new study associated with the planned replacement of the existing culvert under Lee Avenue through which Archers Creek flows east.  The proposed study would determine the optimal design of the new culvert and examine the potential benefits and impacts associated with enhanced tidal flow in Archers Creek under Lee Avenue.  The Board will consider a resolution authorizing a contract with Moffatt & Nichol Engineers, Raleigh, NC in the amount of $20,155 for this study, and will also consider a General Fund budget amendment to appropriate additional funds for the proposed study at the November 13 meeting.

The entire eastern segment of Archers Creek is approximately 1.9 miles long, and runs east from Old Ferry Road (near CVS) to Bogue Sound.  The creek flows from Old Ferry Road through existing pipe culverts under Bogue Inlet Drive, Cedar Street, and behind the EMS Station and Fire Station, and this portion of the creek is primarily a freshwater drainage feature for the central area of Emerald Isle.  Archers Creek then flows between the Town Government Complex and the new McLean-Spell Park and into a coastal marsh area before flowing through an existing 60-inch pipe culvert under Lee Avenue.  Beyond Lee Avenue, the creek flows through significant coastal marsh, with regular tidal fluctuation, before reaching Bogue Sound in the 7000 block of Emerald Isle. 

The existing pipe culvert at Lee Avenue was installed in the late 1970s, and is now approximately 40 years old.  The pipe is deteriorating, and is threatening the integrity of the Lee Avenue roadway in this area.  Most of Lee Avenue is constructed on a causeway feature across coastal marsh, and the 60-inch pipe culvert allows Archers Creek to flow east toward Bogue Sound, and also allows rising tides to flow west beyond Lee Avenue.  As discussed previously, the Town’s FY 18-19 budget includes a total of $15,000 to replace the deteriorating pipe culvert before any significant damage to Lee Avenue occurs.  The Town had been planning to replace the Lee Avenue pipe culvert with an identical (new) pipe this winter, however, we have delayed that work in order to explore a strategy that would enhance tidal flow in Archers Creek in this area in order to promote more consistent flow, promote reasonable creek depths, and promote a healthy coastal marsh environment.  In recent months, there have been concerns raised by nearby residents about the narrowing and shallowing of Archers Creek in this area and the proliferation of invasive vegetation (including phragmites), and there is a general belief that a larger culvert (or culverts) would enhance tidal flow and improve the creek environment in this area. 

The Town is sensitive to these concerns, and the proposed study would enable the Town to better understand the issues associated with the planned culvert replacement and potential tidal flow enhancement.  I am hopeful that the proposed study will eventually guide the Town to a solution that will address the concerns raised by nearby residents.  I have attached a copy of Moffatt & Nichol’s proposal for the Board’s review, and Moffatt & Nichol would be tasked with reviewing the following issues for the Town:

  • the optimal size and design of a new culvert (or culverts) to achieve the desired goals,
  • the potential new or additional flooding impact on upstream property owners during excessively high tides or storm events,
  • the identification of other strategies to promote a healthy marsh environment in conjunction with the culvert replacement (i.e., eradication of existing invasive vegetation, selective excavation or alteration of the creek bottom, and/or other strategies),
  • the potential environmental benefits,
  • necessary permit authorizations,
  • any changes to the Federal and/or State regulatory scheme that may result and impact nearby property owners,
  • estimated project construction costs,
  • any potential Federal and/or State funding opportunities, and
  • any other relevant issues.

Moffatt & Nichol has completed numerous engineering designs and studies for the Town over the past 20+ years, including a 2012 study of the Archers Creek watershed that included a limited review of the Lee Avenue area of the creek (the study primarily focused on the western and central areas of Archers Creek).  Thus, Moffatt & Nichol already has a clear understanding of Emerald Isle and Archers Creek, and is thus ideally suited to complete the proposed study.  (I have attached a July 2012 memo and copy of the summary presentation of the 2012 study.  A full copy of the lengthy 2012 study can be provided upon request.)

As noted earlier, the FY 18-19 budget includes $15,000 for the originally planned pipe culvert replacement.  In light of the community interest in this area of Archers Creek, I am now recommending that the Town use these funds for the proposed study, and the attached General Fund budget amendment appropriates an additional $5,155 to provide the necessary funding for the proposed study.  These additional funds are derived from additional hurricane re-entry permit fees collected during September prior to Hurricane Florence.

The attached resolution authorizes the Town Manager to execute a contract with Moffatt & Nichol in the amount of $20,155.  If approved, Moffatt & Nichol will proceed with required surveying work in the coming weeks, and expects to complete the study and present a final report within 3 – 4 months.  This schedule would enable the Board to consider appropriating funds for construction of the recommended improvements as part of the FY 19-20 budget process and/or form the basis of a potential future Federal and/or State grant application.

As discussed previously, Town staff was scheduled to meet with various regulatory agencies in a formal “scoping” meeting about this potential project on September 17.  This meeting was postponed due to Hurricane Florence, and I have requested that this meeting be rescheduled for later in November.  If the Board awards the contract to Moffatt & Nichol, I expect their staff to attend this meeting with me and/or Interim Town Manager Randy Martin. 

I recommend approval of the attached General Fund budget amendment and resolution authorizing a contract with Moffatt & Nichol Engineers.