April 15, 2010

In Search of Mitigation: Savannah Harbor Deepening Project

Posted on April 15, 2010 by Drew Ernst

With the anticipated Panama Canal expansion (expected to be completed by 2014), the Port of Savannah, Georgia is preparing for the new super-sized container vessels coming its way. Part of that preparation includes a proposed harbor deepening project (“Savannah Project”). The Savannah Project carries with it a price tag of $588,000,000 with a sizable portion of this amount earmarked for mitigation. 

The primary component of the Savannah Project is deepening the existing entrance channel from forty-two feet up to forty-eight feet. The concern with any large-scale project like this, however, is the impact it will have on the surrounding environment and how that impact can be appropriately managed and mitigated. Adding to the mix is the tremendous economic impact the Savannah Harbor has on the entire State of Georgia. Georgia’s deepwater ports support over 286,000 jobs and contribute 14.9 billion dollars in income to the State of Georgia. 

Mitigation is both a hot topic in environmental law, and in many cases, a moving target. The Savannah Project provides a unique case study for both the process of approving a large-scale project like the Savannah Project and the creative and innovative ways mitigation can be discussed and hopefully achieved. 

With respect to the Project, the concomitant mitigation plan includes mitigation for cultural resources, natural resources mitigation, an impact avoidance plan, and in an unusual move, a monitoring and adaptive management plan. Primary concerns include the potential loss of freshwater marsh due to intrusion and an increase in salinity levels; potentially decreased dissolved oxygen levels in the Savannah River; potential harm to the Striped Bass and Shortnose Sturgeon population; and cadmium levels in dredged sediment. As an example, without mitigation of any kind, deepening the channel to 48 feet would impact approximately 1,212 acres of freshwater wetlands. With mitigation, the impact could be limited to 337 acres.

Proposed mitigation measures include altering the flow of fresh and saltwater through a variety of cuts and contouring, construction of a fish bypass structure, closing of selected channels connecting the Savannah River and its tributaries and opening cuts between various adjacent waterways. To specifically address concerns about dissolved oxygen, proposed mitigation efforts call for oxygen injection in several places in the Savannah River through a “bubbler” system made up of injection cones. Each cone would inject up to 15,000 pounds of oxygen into the river per day.

Further mitigation efforts call for the purchase and/or preservation of freshwater wetlands in the upper harbor basin to offset the impact of the Savannah Project on existing freshwater estuaries and the creation of a new 80.5 acres of saltwater marsh to reclaim marshland which will be lost. Further, in a somewhat unusual move, the adaptive management plan would monitor the success of mitigation not only during the construction phase of the Savannah Project, but for up to five years after it is completed. 

The Savannah Project is not without opposition. Beginning with a lawsuit filed in March 2000 to forestall decision-making on the Savannah Project (which was eventually dismissed), critics remain concerned that the Savannah Project will not be appropriately mitigated and are not convinced that mitigation success can be measured in a meaningful way. How the Savannah Project will shape and develop after the draft EIS is issued in the next few months is yet to be seen. However, all involved will continue to search for mitigation.

A full overview of the Savannah Project and its proposed mitigation efforts can be found here

Tags: Water


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