Harbor River Bridge banner

Harbor River Bridge


SCDOT is constructing a new high-level fixed-span bridge and is removing the existing swing-span bridge along US 21 (Sea Island Parkway) over the Harbor River in Beaufort County. The US 21 existing bridge is more than 78 years old and provides the only means for vehicular transportation from the mainland to Harbor Island, Hunting Island, and Fripp Island.

The new high-level 3,353 foot long fixed-span bridge will provide uninterrupted access for shrimping and sailing vessels along the river below as well as provide improved safety for motorists crossing the bridge itself. The new 65-foot high bridge will offer 12-ft wide lanes with 10-foot shoulders in each direction. The current bridge will remain open to travel until construction of the new bridge is complete.

side view of Harbor River Bridge

Existing Harbor River Bridge swing-span.

Aerial view of existing Harbor River bridge

Existing Harbor River Bridge.

Aerial view of existing Harbor River bridge

View of Harbor River Bridge swing-span.

Rendering of proposed bridge

Rendering of proposed Harbor River Bridge replacement.


Project Milestones

  • January 2019 Released for Construction Plans Completed
  • April 2019 NPDES permit issued
  • Spring 2019 Begin Bridge and Roadway Construction
  • Late Summer 2021 New Bridge Open
  • Fall 2021 Begin Demo of Old Bridge
  • Early 2022 Substantial Project Completion

Traffic Alerts

Drivers traveling near the Construction Zones are asked to be aware of equipment and crews working in the areas and to comply with traffic control signs, reductions in speed limits, and message board information. Drivers are also asked to be aware of the new and changing traffic patterns during the project. Together we can eliminate work zone accidents during construction. Thank you!

Should you have any questions or need further information, please contact SCDOT Resident Construction Engineer Sarah Gaffney at (843) 514-9847 or at GaffneySH@scdot.org.

Project Contacts

  • Project Office
  • 134 Coffin Point Rd.,
    St. Helena Island, SC 29920
  • 843-745-8765
  • Sarah Gaffney, PE
  • SCDOT Resident Construction Engineer
  • 843-580-8542
  • Contractor: United Infrastructure Group
  • Designer: Infrastructure Consulting & Engineering
  • CEI: Michael Baker International