Update on Charleston’s $1.1 billion sea wall plan

Charleston Peninsula Study Optimized Plan

Charleston Peninsula Study Optimized Plan | Photo by Management Support Branch, Charleston District, USACE

The US Army Corps of Engineers recently released an update on its Charleston Peninsula Sea Wall proposal — the original plan was released in April 2020. The sea wall would be built around downtown Charleston ~8 feet above the tide flood line to protect against storm surge + sea level rise.

The total cost of the project has decreased from $1.7 billion to $1.1 billion. The City of Charleston would contribute 35% + the federal government would contribute the other 65%. For every $1 invested in the project, there will be an estimated $10.20 return on investment.

The wave attenuating structure, or rock jetty, has been removed from the project and living shorelines such as oyster reefs along the western side of downtown have been added. Wetland impacts have been decreased from 111 acres to 35 acres.

The update also includes $50 million in aesthetic adjustments to better incorporate the sea wall into historic Charleston. The new plan features modeled storm surge impacts to James Island, West Ashley, Mt. Pleasant, Daniel Island, and North Charleston.

If you’re interested in a comprehensive breakdown of the update, register for tomorrow’s free webinar from 4-5:30 p.m. with the Historic Charleston Foundation.