By Billy Birdwell, Senior Public Affairs Specialist
As the Savannah District continues designing and planning the Savannah Harbor Expansion Project (SHEP), some residents near the Corps reservoirs express concern the proposed deepening could increase downstream outflows.
Let me state the simple answer up front: The proposed deepening of the Savannah harbor will have no impact on outflows from the reservoir system. None.
The original legislation authorizing construction of dams on the Savannah River cited navigation as a purpose for building the dams. At the time that included the Savannah harbor and barge traffic on the river. Commercial traffic upstream of the Savannah Harbor ended in 1979 although an occasional barge will take something extraordinary upstream when other transportation modes are more difficult.
Today, supporting downstream navigation means keeping enough clean, fresh water in the Savannah harbor to maintain fish and other aquatic species particularly during routine maintenance dredging that keeps the channel and harbor open to commercial traffic. The harbor itself will always have sufficient volumes of water to float commercial shipping since the harbor is subject to ocean tides.
Keeping enough oxygen in the harbor without increasing reservoir discharges posed a challenge to SHEP planners. In studies leading up to the recommendation to deepen the harbor, they searched for ways to maintain adequate dissolved oxygen using the current water manual for the reservoirs. Planners determined oxygen could be injected into the river above and around the harbor to maintain current conditions. This proven method could be controlled with more precision than sending water downstream and could also react more quickly to changing conditions. It also protected the reservoirs. You can learn more about SHEP from our web pages by clicking here.
SHEP will impact the area around the New Savannah Bluff Lock & Dam. In order to reopen traditional habitat for sturgeon and other species, plans call for a large fish passage around the lock and dam. But even this fish passage will have no impact on the reservoir levels or even the pool behind the lock and dam.
Water is precious and getting more precious. By using an oxygen injection system at the harbor we reap the benefits of increased transportation efficiencies of a deeper harbor while still following the existing outflow restrictions.