St Johns County aims to restore 20 miles of hurricane-damaged shoreline

St. Johns County previously endured two major hurricanes - Matthew in 2016 and Irma in 2017. Twenty miles of Atlantic Ocean shoreline were damaged by the hurricanes, washing away thousands of cubic yards of sand and leaving the area susceptible to future damage as well as reducing natural habitat for several endangered species. As a result, this project posed several challenges for the Continental Heavy Civil (CHC) / GHD Design-build team.

The Federal Emergency Management Agency (FEMA) authorized funding to provide 750,000 cubic yards of beach-compatible sand. However, the funding came with a deadline for construction to be completed before December 2021. This challenged the team to complete a fast-tracked design and permitting process with an FDEP project permit secured in five months.

For construction, the beach-compatible sand was required to be sourced from inland mines located in north-central Florida. The material had to be transported to the site via truck and placed on the impacted beach and dune system by mechanical means. The shoreline impacted by the hurricanes had minimal site access for construction. Some sections of the County beaches have no usable public access points. Additionally, not all beachfront property owners provided easements for construction. This discontinuous sand placement created design and construction challenges due to volume changes and tapers, variable designs and reduced efficiency.

Design and construction also had to consider the extremely sensitive environment of the project site and existing shoreline infrastructure. Despite all work being completed above mean high water, several threatened and endangered species required critical consideration. These included marine turtles, gopher tortoises, nesting shorebirds, and Anastasia Island Beach Mice. Finally, hundreds of private dune walkover structures and thousands of feet of private sand fencing had to be accounted for in all project phases.

Our team was able to tackle each challenge with resourceful innovation.

To fast-track the permitting and design process, we called upon additional resources from a network of 3,000 staff nationwide to submit 60% design and a FDEP Joint Coastal permit application in six (6) weeks.

CHC addressed major construction concerns by securing temporary access points on private property, requiring significant coordination, environmental monitoring, engineering site modifications, and stakeholder engagement. These sites are used to transport construction equipment and sand to the beach. Additional coordination meetings with residents and the County are required to coordinate the easements granted as construction progresses.

Both CHC and GHD extensively coordinated with the Florida Fish and Wildlife Commission (FWC), granting relocation authorizations for marine turtles and gopher tortoises. Each species required extensive coordination, relocation fees, and delicacy towards the endangered and threatened quality of the animals. The construction schedule was also modified based on nesting seasons and the density of nests in specific areas. Construction also gave particular care to the dune walkover structures, crews cast sand under and around the dune walkovers and coordinated for removal and replacement of sand fences. Design template, schedule, and construction methodology were key in finding solutions.

The impact of this project is to restore the shoreline to its pre-storm condition and prevent damage from future extreme weather events. Currently under construction, the project site has already been subjected to a Nor'Easter with hurricane-like conditions. Areas where construction was already complete saw increased protection from wave and wind forces. The completed project will protect the upland improved infrastructure located along portions of critical St. Johns County Shoreline.