ASBPA 2014 – Abstract
Chris Mack
Presentation Title: Coastal Engineering Design Concepts for Living Shorelines.
Presentation Abstract: You’ve been asked to design a conceptual living shoreline alternative to convert
an existing boat marina site to a living shoreline and recreation site while maintaining mitigation
objectives (i.e., shoreline stabilization). The site is located in a tidally influenced tributary along the
Neuse River in North Carolina. The marina was abandoned following severe hurricane damage and is
used on occasion for fishing and kayaking. The site is bounded on one side by a large tributary and the
other by a small tributary with various native aquatic habitats. The marina site currently consists of a
steel bulkhead, docks, piles, utilities, a boat ramp, and other unnatural features. The goal of the living
shoreline solution is to restore the site to more natural conditions and still provide recreational
opportunities. Site conditions currently constrain options including moderate currents and waves along
the shoreline to be restored. Further, the steep slope and existing grand oak trees limit the footprint
that would be needed to support a complete living shoreline regime. Construction funds are limited, so
designs need to be cost effective.
This presentation details many of the design challenges (and solutions) and concepts encountered when
designing a living shoreline on a developed shoreline bounded by multiple geophysical, anthropogenic,
fiscal, and aquatic constraints. Final conceptual designs included the creation of a living shoreline
“pocket habitat”, which leveraged portions of the bulkhead to support upland sediments and aquatic
plant regimes. Other features included a nature trail, preservation of five large grand oak trees, and
limited reuse of a boat ramp for kayak launching. The design setting also included natural wooden
benches, picnic areas, and fishing opportunities.
This design was compared to other variant designs leveraging an offshore submerged sill, complete
removal of the bulkhead, or restabilization of the shoreline with bulkhead repairs or a rock revetment.
The pros and cons compared include aquatic habitat benefits, costs, mitigation, recreational use,
operations, and maintenance.
-----------------------------------------------------------------------------------------------------------------------------------------Lead Presenter:
Chris Mack, PE
Coastal Project Manager,
AECOM
3820 Faber Place Drive, Suite 300
North Charleston, SC 29405
Chris.Mack@aecom.com
Lead Presenter Bio: Chris Mack has over 23 years of coastal engineering and water resource experience
in the public and private sectors. This includes more than 13 years with the US Army Corps of Engineers
and 10 years with private coastal and marine engineering firms. He currently manages a staff of coastal
engineers and CAD/GIS technicians for coastal engineering studies and projects on the east coast of the
US involving storm surge modeling, coastal hazard analysis, shoreline restoration, dredging and
ASBPA 2014 – Abstract
Chris Mack
navigation, ecosystem/habitat restoration, coastal processes, beach/inlet management plans, and
climate change. He serves as a lead for the ASFPM’s coastal mapping and technology sub-committee.