Georgia port expansion pays dividends to the economy, companies and jobs
At a glance
The Port of Savannah is the country’s fourth busiest container port and the second busiest on the U.S. eastern seaboard. Georgia ports contribute $32 billion to the state economy and serve as the export center for goods transported throughout the Southeast.
As the size of international vessels has grown, so has the need to create a port that can capably handle them. With the Savannah Harbor Expansion Project (SHEP) and infrastructure enhancements at the port, the Port of Savannah will conveniently accommodate the new standard vessel growth for global shipping.
The mission
The Savannah Harbor Expansion Project is aimed to increase navigation channel capacity, improve vessel safety and boost economic growth.
The challenge
Given the proximity of the shipping channel to sensitive estuarine resources, the U.S. Army Corps of Engineers (USACE) Savannah District, Georgia Ports Authority, and state and federal partners conducted exhaustive engineering and environmental studies to identify the environmental impacts that would be expected from the project and ensure those impacts will be offset through mitigation. Deepening only accounted for half of the SHEP total program cost; the other half included a range of environmental mitigation projects designed to mitigate the impacts of deepening.
Environmental mitigation includes installing a dissolved oxygen (DO) system, significant flow rerouting measures, preserving 2,245 acres of freshwater wetlands for the Savannah National Wildlife Refuge, and other environmental and cultural mitigation measures.
Our response
One of the key mitigation features of the SHEP was the construction and operation of two oxygen injection plants designed to offset reductions in DO throughout the Savannah River and estuary caused by navigation channel deepening. The two plants, strategically located to best mitigate DO impacts, generate and inject highly oxygenated river water into the Savannah River during the critical summer months. GHD has provided services in support of these plants and their continued success, including:
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Plant readiness support in advance of and during two critical test periods, known as the Test Run and Startup Run.
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Multidisciplinary design services at both plants to improve plant operations and efficiency.
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Design services at the Upriver location to combat erosion by extending an existing sheet pile bulkhead.
GHD’s other primary support area for the SHEP has been hydrodynamic and water quality modeling and monitoring of the deepening and mitigation features and include:
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Modeling of the two critical test periods, the Test Run and Startup Run, for the entire Savannah Harbor and estuary.
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Revisiting the effectiveness of the Sediment Basin—the final flow re-routing mitigation project—by updating the SHEP hydrodynamic model and analyzing the impacts of this feature on salinity intrusion and changes to localized flows and shear stresses.
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Additional hydrodynamic and water quality modeling for the Sediment Basin at the request of agencies and stakeholders to assess the impacts of the Sediment Basin on salinity, habitat suitability and water quality. These results will be used by the USACE in a supplemental Environmental Assessment.
The impact
The nearly one-billion-dollar project deepened the Savannah Harbor federal shipping channel from a depth of 42 feet to 47 feet, and also extended the entrance channel by seven miles and deepened the outer harbor by approximately 18.5 miles into the Atlantic Ocean. This deepening expedites the flow of cargo to and from global destinations by allowing for larger, more efficient container vessels to use the Port of Savannah with fewer weight and tidal restrictions.
The SHEP is expected to net more than $282 million in annual benefits to the nation and has a benefit-to-cost ratio of $7.30 for every $1 invested.