Savannah River Cutoffs Might See Restored River Flow

In the late 1800s, the U.S. Army Corps of Engineers and others cut through 46 bends in the Savannah River below Augusta to aid commercial navigation. Now the corps wants to know how these “shortcuts” have impacted the river’s ecosystem and which ones make the best candidates for restoring.

In order to look into how to restore some of the disconnected 27 miles of bends, the Savannah District is working on the congressionally authorized Savannah River Below Augusta Ecosystem Restoration Study (SRBAeco).

“The study focuses on the restoration of form, function and dynamic process of the Savannah River cutoff bends for the benefit of fish and wildlife habitat, wetlands, and the associated hydrology and hydrodynamic processes,” said Nathan Dayan, Savannah District National Environmental Policy Act specialist.

As part of study, the Savannah District formed a project delivery team which is tasked with defining the problems that need to be solved, opportunities to solve the problems, objectives to be achieved, identifying any constraints and developing an initial array of alternatives to meet the objectives.

“When the cutoff bends were disconnected from the main river it led to decreased interaction between surface water and ground water, a conversion of wetland type, and seasonal reduction of fish and wildlife habitat,” said Robin Armetta, Savannah District Planning Branch biologist.

“That resulted in approximately 800 acres of aquatic habitat and 990 acres of bottomland hardwood forest being seasonally disconnected from the Savannah River, and created stagnant water conditions, increasing temperatures and decreasing dissolved oxygen in the cutoff bends.”

Duck Cut is an example of a cutoff bend being disconnected at both ends, which affects the water quality of the Savannah River and the quantity of available aquatic habitats. A Savannah District team is developing a solution to restore some of the 46 bends put in the river for historical commercial navigation dating back to the late 1800s. (Photo: Google Earth)

Through analyzing subjects like benefits to fish and wildlife habitats and natural overbank flooding in the swamps along the river the team hopes to recommend a plan to address cutoff bends identified as those with the greatest restoration potential.

“We’ve come up with eight locations that would provide the most benefit by measuring the effects of actions such as excavation of pilot channels, installation of training structures, and the removal of trees and roots within the cutoff bends to restore the aquatic habitat,” said Armetta.

The study is showing that going forward something can be done to “fix” disconnected bends in the river that were the result of historical commercial navigation needs of the time.

Bob Sirard, a project manager with the Savannah District has a simpler way of describing the idea behind the SRBAeco.

“You improve it, or you don’t do it,” he said.

The study is scheduled to run until September 2021, and if it recommends restoration then work could begin as early as 2022.