The Tepa Companies recently finished a tidal gate project for the U.S. Army Corps of Engineers (USACE) at Hunter Army Airfield (HAAF), including construction, engineering design, and environmental services. Tepa was contracted to construct and design needed repairs to a tidal flood control structure to protect national register-eligible architectural resources and minimize continued adverse impacts on resource sites on HAAF. The repairs included updates to the tide gates, commonly used to control incoming water flow, initially installed in 1898. Historic structures like 19th-century water control features and a raised causeway damaged by the breached tide gate from previous weather events also needed repair.
HAAF sits on 5,400 acres of land in Savannah, Georgia; it is home to the aviation elements assigned to the 3rd Infantry Division headquartered at Fort Stewart, supporting approximately 4,600 soldiers. It also contains archeological sites protected by the Archeological Resources and Protection Act and the Little Ogeechee River, believed to be named from the Muskogean word meaning “River of the Yuchis,” an Indian tribe that once lived near the river. The river is known for many native wildlife habitats, including manatees.
The project had unique challenges that included project access and animal habitat. Land surveyors and construction crews could only access the site through the Little Ogeechee River, where the manatee’s schedule was monitored. Construction was restricted to only several months when the manatees were not present due to cooler water temperatures. Large barges and cranes navigated the narrow channels and adapted to hourly changes in tidal water depths.
To further avoid harm to the river mammals, Tepa designed and installed manatee grates on the upstream side of the check values, preventing manatees from entering or getting stuck and hurt. Other unique project challenges included alignment, working above the water line and tidal flow issues.
Tepa’s work on this project ultimately ensured the HAAF’s tidal gate system functions as intended. As part of the project, sand was placed to encapsulate and preserve historical features, helping prevent further deterioration. Repairing the tidal gate also minimizes potential flooding, reduces continued erosion of the upstream rail assets supporting deployment and protects the natural and cultural resources entrusted to the HAAF.
