Advocacy

US Army Corps of Engineers Charleston Peninsula Flood Study

Preservation-Society , April 21, 2020

This morning, the US Army Corps of Engineers (USACE) released their draft report on the Charleston Peninsula Coastal Flood Risk Management Study for public review. Since 2018, the Army Corps has been evaluating a range of flood protections, from living shorelines to levees and walls, and is now putting forth their recommendations on long-term solutions for storm surge on the peninsula.

Map of proposed storm surge wall, courtesy of the USACE

What is it?
More commonly referred to as the “3×3” plan, this study is funded by the USACE at a cost of $3 million, over 3 years. Charleston is one of many communities engaging the Corps on this kind of study and will be competing for funding based on a cost-benefit analysis of the proposed projects. However, if Congress approves the plan, the federal government would cover 65% of the cost, while City Council would have to commit to paying the remainder.
 
USACE Recommendation
The Tentatively Selected Plan calls for a 12-foot storm surge wall along the perimeter of the peninsula (perceived height will vary based on ground elevation) and a significant breakwater structure offshore of the Battery, as well as relocation, buyout, elevation or floodproofing of individual properties. In total, the proposed project would cost $1.75 billion, of which the Army Corps would only contribute to the actual infrastructure, leaving the City on the hook to pay for any aesthetic or recreational features. 

Example of a surge barrier wall in New Orleans

Next Steps
The Army Corps is offering 60 days for public review of the report, primarily by digital means. Thereafter, the USACE will conduct a feasibility analysis of the selected proposal and then send the study to Washington D.C. for review by the Corps’ Civil Works Review Board. To meet the 3-year deadline, the plan must be finalized and approved by the Chief of Engineers by October 2021, when it will then be presented to Congress for funding consideration. 

The proposed perimeter wall would significantly alter the appearance of Charleston’s most iconic historic places, like the Battery

The PSC’s Take
This is the single largest infrastructure investment in Charleston’s history and would require the readjustment of all other flood-mitigation priorities from a funding perspective. The cost share for this project would potentially put a $600 million burden on the City, when $2 billion of existing flooding infrastructure needs have already been identified from West Ashley to Johns Island. It is important to note that the proposed system is focused solely on storm surge and provides little protection against storm water inundation or sunny day, high tide flooding. The PSC feels careful consideration must be given to the City’s return on investment for this undertaking. 
 
We also have great concerns over the impacts of this project on Charleston’s historic and natural resources, residential quality of life, and heritage tourism industry. While the plan provides long-term protection for the majority of the peninsula, it also acknowledges adverse impacts on historic and archaeological resources, as well as our city’s visual character. For residents and visitors alike, how will a 12-ft wall alter the quality of our experience of Charleston? At this point there are many questions to be answered to understand the implications of this proposal for our city’s future.
 
Based on the incredible cost and impact of this project, coupled with the extensive list of unknowns, it is imperative that this project proceed at a responsible pace to provide extensive opportunity for community education and input. The timeline as proposed does not allow for sufficient community engagement, and the PSC calls on city leadership and the USACE to extend the public review and comment period to 120 days and undertake a comprehensive educational campaign to fully explain this complex plan to the community. As this project progresses, we will work to ensure that the public has the information necessary to understand the details of the proposed approach.

Review the Army Corps Plan and submit comments here by June 19, 2020. Alternatively, comments can be mailed to the USACE Charleston District Office at 69 Hagood Avenue, Charleston, SC 29412.