Planning board OKs 100-foot seawall and 450-square-foot dock; board hears technical debate over hybrid seawall materials

The Town of Highland Beach Planning Board voted unanimously June 12 to approve Development Order application PZ-25-24, a special-exception request to install a 100-linear-foot seawall and an associated 450-square-foot dock at 4306 South Ocean Boulevard.

Town Planner Ingrid Allen told the board the seawall and dock have a current Florida Department of Environmental Protection permit and that Army Corps of Engineers approval was not required. Allen said plans submitted to FDEP initially showed a seawall elevation of 6.17 feet NAVD while the town plans used a 7.0-foot base flood elevation; she said FDEP sent email correspondence accepting the adjustment. Allen also noted the property is not an interior lot and must comply with the five-foot setback; staff found the proposal compliant with setback and seawall-cap limits in town code and consistent with section 30-36(a).

Arthur Teedeman, identified as representing APH Reconstruction, made a technical presentation describing a “hybrid” seawall system that uses vinyl panels filled with concrete and glass-fiber-reinforced polymer rebar (GFRP). Teedeman described GFRP as a nonmetallic rebar that he said is “three times stronger, four times lighter” than traditional rebar and said the system is engineered to avoid the corrosion and spalling problems he attributed to steel rebar.

Several board members and residents asked technical questions. One resident raised long-term settlement concerns for Belle Lido Isle and asked whether a sheet-like fiberglass panel driven into resistance would perform on a site that has historically settled. Teedeman said the technology has been installed for over two decades in other locations and discussed options — helical anchors, batter piles, and GFRP elements — to suit site conditions.

Board members also questioned tieback materials shown on the submitted plans. Teedeman acknowledged the engineering specification on the submitted plans called for hot-dip galvanized (HDG) steel anchor rods; he said the contractor can substitute helical anchors or nonmetallic options and that those substitutions commonly occur at the building-permit stage. Building Official Jeff Remus described the submitted design and materials as a “far superior” method compared with older seawalls and said the town’s structural-review process would verify any changes at permitting. Remus recommended that the board could make a condition requiring nonsteel tiebacks if it preferred.

Staff said the plan set was date-stamped May 28, 2025, and that the planning-board approval would require the applicant to obtain a building permit and initiate construction within two years under section 30-21(g). After public comment and board questions, a board member moved to approve the application. The roll call recorded affirmative votes from Member David, Vice Chairperson Rosen, Member Brown, Member Powell, Member Axelrod and Chairperson Mendelson; the motion carried.

Allen and Remus told the board that material substitutions (for example, switching from HDG steel anchors to helical or nonmetallic anchors) are typically reviewed by the building official and the town’s structural engineer during permit review and would require engineer calculations and pull tests where applicable. Residents who spoke at the hearing expressed concern about ongoing island settlement and asked staff to confirm the sequencing of seawall and house reconstruction; staff explained that seawall installation is often done prior to significant backfill or house construction so that the property can be graded and prepared.Because the project is in an area previously reviewed by the commission — staff noted the planning board recommended a related townhome application in November 2024 and the town commission approved final action Dec. 17, 2024 — staff emphasized the current approval implements the seawall/dock special exception consistent with prior decisions.