Misconceptions on Fish Passage Corrected

We are aware of concerns in the community about the future of the New Savannah Bluff Lock & Dam (NSBL&D) and changes in the proposed fish passage. We believe there are presently some assumptions or misinformation circulating within the community about those topics and the legislation passed in the Water Infrastructure Improvements for the Nation (WIIN) Act. For background on how this law impacts the NSBL&D, see our summary here.

Most of the misinformation can be summarized under five main categories. We address them below:

ASSUMPTION: The law’s proposed solution for the NSBL&D will cause flooding in downtown Augusta, Georgia, and surrounding communities.

RESPONSE:  Incorrect. Although we are still in the process of developing a solution that meets the intent of the law, one of our major goals is to identify a design that will not increase flood risks in downtown Augusta or North Augusta. The current lock and dam structure was not authorized as a flood control structure and does not function as a flood storage reservoir. It is a “pass through” structure that allows flows to pass unobstructed over the dam. What comes into the pool goes out of the pool. We have typically raised the gates when high flows occur, but that performed to protect those features from being damaged by high water. That operation does not constitute a flood control capability. River flow volumes that are high enough to flood metropolitan Augusta or North Augusta will have long overtopped and overcome the NSBL&D.

ASSUMPTION: In order for the law’s solution not to cause flooding in Augusta, the new pool level must be lowered three feet.

RESPONSE: Incorrect.  It is true that the elevation range of the pool has not yet been determined and is one of the factors the Corps is evaluating.  Substantially lowering the pool could adversely affect industrial water intakes along the pool.  We are coordinating with the industries to identify what pool elevations they need to maintain their operations.  We do not want to adversely affect those industries.   We are also considering different locations for the proposed structure in the WIIN Act. The possibility remains the final pool level could be lower than the current level. This may be needed to minimize flood heights in rural areas near the lock and dam that are in the flood plain.  We are presently modeling the flood risks and impacts.  A lot of design work and modeling is still ahead of us.  However, right now we can assure stakeholders that our goal is to design a structure that won’t increase flooding even in the present flood plain, while minimizing impacts to upstream users.  We are using the FEMA model as a basis to evaluate upstream impacts and our analysis will be coordinated with FEMA.

MISCONCEPTION: The law’s proposed solution is much more costly ($100 million) than the original solution to have a fish passage circumvent the NSBL&D (at $50 million).

RESPONSE: Incorrect. The law does not identify the solution. Back in 2011 we put together an Environmental Impact Statement that evaluated the harbor deepening. One of the analyses in that document was a conceptual design for a rock ramp weir that had an estimated cost of roughly $100 million. However, the costs in the EIS were very rough order of magnitude. Our current evaluation process involves new technical data and much more detailed analysis to help us identify the most cost-effective way to meet the intent of the WIIN Act. We cannot yet offer certainty on the cost for the proposed solution, but we are confident that it will be less than $100 million. However, it’s important to consider that the upfront cost of a structure that serves multiple purposes may be a little higher than the previous estimates of a fish passage alone. We believe the annual operation and maintenance costs for a fixed structure that meets the WIIN requirements would be more affordable than both a fish passage and a rehabilitated lock and dam.

MISCONCEPTION: Funding to rehabilitate the NSBL&D was included in the budget for the Savannah Harbor Expansion Project (SHEP).

RESPONSE: Incorrect. No funds from SHEP were authorized for rehabilitation of the lock and dam. A small amount of SHEP funding was budgeted to modify two gates of the NSBL&D so that the original fish passage design would function properly – but that is all. The NSBL&D is presently in poor shape and would remain so. Rehabilitation of the structure would cost approximately $30 million and Congress has not provided such funds for 25 years. Since the NSBL&D is in caretaker status, there is very little chance funds would be appropriated to repair the structure. Like all other federal projects, it must compete for limited funding with projects across the nation, many of which produce more benefits to the nation and receive a higher funding priority. The large costs for repair make the NSBL&D a poor investment from the national perspective.  Furthermore, the original fish passage depended on a fully functional NSBL&D in order to work as designed. Yet, the lock and dam are in such disrepair that our engineers say its collapse is inevitable. This is why the WIIN Act legislation is good news for the Cities of Augusta and North Augusta:  it solves the problem of pending failure of the lock and dam and provides federal protection for the pool.

MISCONCEPTION: Building the rock weir will necessitate the draining of the pool during construction.

RESPONSE: Incorrect. The WIIN Act legislation specifies the removal of the New Savannah Bluff Lock and Dam will not occur until the completion of construction of the new structure.  The Corps has experience “working in the wet” and does not anticipate the need to drain the pool during construction of a new structure.

We welcome questions and input.

~Russell Wicke, Corporate Communications

About US Army Corps of Engineers Savannah District

The U.S. Army Corps of Engineers Savannah District oversees a multi-million dollar military construction program at 11 Army and Air Force installations in Georgia and North Carolina. We also manage water resources across the Coastal Georgia region, including maintenance dredging of the Savannah and Brunswick harbors; operation of three hydroelectric dams and reservoirs along the upper Savannah River; and administration of an extensive stream and wetland permitting and mitigation program within the state of Georgia. Follow us on Twitter @SavannahCorps and on Facebook.com/SavannahCorps
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