Charleston Again Turns to NOAA for Sea Level Rise Guidance

The Takeaway: A Digital Coast expert's sea level rise briefing moves officials to recommend higher elevations on new buildings.

In the 1970s, tidal flooding in Charleston averaged twice per year. By 2045, tidal flooding is projected to strike up to 180 times yearly. Charleston officials recently upped elevation guidance on new, city-owned buildings and infrastructure by one-half foot. They were moved to act after a Digital Coast expert briefed them on the latest sea level rise scenarios covered in 2018’s Fourth National Climate Assessment. For the second time in four years, these officials turned to NOAA’s Office for Coastal Management to inform their sea level rise strategy.

Charleston’s stricter elevation guidance—from 1.5/2.0 feet to 2.0/3.0 feet—appear in the second edition of Charleston’s Flooding and Sea Level Rise Strategy and reflect the greater probability of intensified sea level rise by 2070. Less vulnerable new infrastructure, such as parking lots, would be elevated by two feet. Long-term critical infrastructure, such as medical facilities, would be elevated by three feet.

The Charleston strategy aims to prepare the city for the next 50 years. Slated for completion by 2020, it will cost approximately $154 million and include projects to improve drainage, raise the elevation of busy streets affected by flooding, build and extend seawalls, and retrofit public housing.

The city’s original sea level rise strategy, adopted in 2015, was aided by technical mapping assistance and a Regional Coastal Resilience Grant of $766,887 from NOAA’s Office for Coastal Management. The grant was awarded to the South Carolina Sea Grant Consortium on behalf of the Charleston Resilience Network. (Original story 2017/Updated 2019)

Partners: Charleston Resilience Network, City of Charleston, College of Charleston, South Carolina Sea Grant Consortium, South Carolina Department of Health and Environmental Control, The Citadel, University of South Carolina