Lowcountry Flood Mitigation

Flooding and Drainage Issues

Flooding in the Lowcountry is not a new problem.  Just ask any resident of Charleston – and you will likely hear a story.  Due to its low lying coastal elevation, close proximity to rivers and the ocean, and poorly planned development on filled-in wetlands, the City of Charleston has experienced drainage and flooding complications since before its founding.  Flooding in the city is attributed to:

• Tidal flooding and storm surge resulting from extreme weather.
• Flash flooding that overburdens the City’s outdated drainage infrastructure.
• Riverine flooding caused by heavy and prolonged rainfall that inundates the capacity of river and stream channels.

In 2016 alone, Charleston experienced 50 days of tidal flooding.  This is a staggering increase from an average of four days just five decades ago.  The booming growth rate exacerbates the threat that sea level rise already poses to the City of Charleston and Lowcountry region as a whole.  It no longer takes a catastrophic storm to cause flooding in the region.  Rainfall paired with a high tide floods numerous neighborhoods and key corridors causing major disruptions to transportation patterns.  All too often drivers are forced to try and maneuver through dangerous flooded streets or avoid major roads altogether to save their vehicles.  Millions of dollars worth of property has been damaged due to flooding in the Lowcountry.  As if our coastal region is not vulnerable enough, the Berkeley, Charleston, Dorchester region ranks in the top 15 U.S. metro regions prone to hurricane-driven storm surge damage.

It is time for the City of Charleston and Charleston County as a whole to address the problem. Charleston must be better equipped to recover from flooding after extreme rain events. Scientists predict that sea levels are expected to rise 2.5 feet over the next 50 years. What does this mean for Charleston?  Simply put, tidal flooding could occur as or more frequently than 180 days in the year 2050.

Funding the Solutions

We already know that over $1 billion in drainage infrastructure is needed to bail out Charleston County residents struggling to keep above water.  This goes beyond a flooding issue into a livability and public health crisis. For the second year in a row, Mayor Tecklenburg named flooding as his top priority during his annual State of the City address. Problem areas have been identified and their respective drainage issues have been studied extensively by local governments.  However, few solutions have been identified to fund these projects in their entirety.

In 2016, Charleston County taxpayers voted to raise the local sales tax an additional half-cent in order to fund mass transit, capacity improvements to numerous roads, and for the protection of greenspace. The ½ Cent Sales tax money is a $2 billion source of funding which is available now and must be used to fund drainage infrastructure projects in Charleston. It is the largest and most readily available funding source to address countywide flooding.  The self-imposed decision to raise taxes was a result of residents determined to solve a problem after years of inaction by local and state leaders. There are desperately needed drainage improvement projects in neighborhoods throughout the county, from Shadowmoss in West Ashley to Pepper Hill in North Charleston to The Old Village in Mount Pleasant to the East Side of downtown Charleston that are being severely and repeatedly flooded.  County Council must proceed with these and other drainage projects before investing in new roads.  If residents are not able to safely live in their homes and travel to and from work, then how will they be able to pay taxes to fund new roads?  If funds are left over following completion of the drainage projects, then Council can begin appropriately deciding how to allocate the remainder of money.

Addressing the Problems

Evidence is mounting that rising tides, intensifying rainfall and increased frequency of nuisance flooding will continue to affect all residents of Charleston in one way or another.  In response to growing community concerns around flooding, the Coastal Conservation League along with a group of organizations and individuals founded the grassroots coalition called Fix Flooding First in the summer of 2018. This community based coalition is raising awareness around flooding issues and advocating for policy based solutions. Accommodating the steady pace of growth in the Charleston metro region without exacerbating flooding will be key to ensuring the safety and livability of this place in the future.

Increasingly, coastal communities around the United States are shifting to smarter growth and building practices that focus on resilience. Charleston City and County officials should be taking similar measures to reduce flooding risks such as prioritizing green infrastructure in new all development plans, avoiding the disturbance of wetlands that serve as a sponge in our soggy environment, protecting tree canopies that absorb and retain water, and preventing destructive development from occurring in vulnerable low lying areas.

Charleston County and the City of Charleston are beginning to show signs of progress towards addressing flooding through planning efforts. In 2019, Charleston County added a Resilience Element into the Comprehensive Plan and updated stormwater and building codes to be more restrictive. The City of Charleston updated their Flooding and Sea Level Rise Strategy.  The City also hosted the Dutch Dialogues- a collaborative effort of national and international water experts working alongside local teams in Charleston to conceptualize a future of living with water and encourage a new approaches to addressing the challenges. Many promising planning efforts are underway but bold action from local leadership is required to bring them to life.

Tools for Mitigation

Though flood mitigation tools like home buyouts do not fix the root of the issue which is preventing development in the floodplain, they do provide significant benefits and can save local governments money when planned well.  That is why the Coastal Conservation League is partnering with the Natural Resources Defense Council (NRDC) to explore possibilities for voluntary buyouts as a tool to permanently eliminate the risk of flood damages. In 2019, the City of Charleston bought out and demolished 32 townhomes in the Bridgepointe subdivision of Shadowmoss in West Ashley. The structures were demolished and the restored floodplain will be preserved as open space in perpetuity. These properties and other in the future can be used for parks, public access to waterways, or other green infrastructure projects that further reduce flood risks. With sea levels projected to rise three to six feet by the end of the century, we need to make it easier for homeowners to get assistance to move out of harm’s way.  The Conservation League is partnering with the City of Charleston and NRDC to identify ways to make local buyouts more accessible and to make them happen much faster in a manner that supports the homeowners.

Progress can also be seen at the State level. In 2018, Senator Steven Goldfinch introduced legislation to establish the South Carolina Resilience Revolving Fund which would offer low interest loans and grants to help remove homes from floodplains. The Coastal Conservation League is supportive of this bill which would create South Carolina’s first revolving fund dedicated to flood related home buyouts, helping residents who want to relocate out of the floodplain access those opportunities.