Evaluating Ordinances and Policies to Reduce Flood Risk

Horry County, South Carolina

Featured image for the project, Evaluating Ordinances and Policies to Reduce Flood Risk

Waccamaw River Memorial Bridge in Horry County, SC (Courtesy of Wikimedia Commons)


Horry County is a coastal community in the northeastern coastal plain of South Carolina. Located along the Atlantic Ocean, with three major rivers (Waccamaw, Little Pee Dee, and Lumber Rivers), more than 50% of the incorporated county includes wetlands, marshes, and other water features. Well known for its beaches, including the popular tourist destination, Myrtle Beach, Horry County is also home to the City of Conway, a historic river town established in 1732 along the Waccamaw River, as well as numerous wetlands, forests, and farmlands. 

Horry County is also the largest county in the South Carolina and the second fastest growing municipality in the nation. More than 35,000 people have moved to the county over the past two years and conservative estimates of population growth predict 275,000 new residents by 2040. The growing population of Horry County has lead to an increase in development and urbanization. However, the current county codes, ordinances, and infrastructure were not designed to accommodate the current pace of population growth and development. Since 1996 the county has seen a 22% increase in impervious cover, and loss of forested and wetland area. With about 24% of the county located within the 100-year floodplain, continued development and urbanization have contributed to an increase in flooding. 

Over the past four years, Horry County has experienced 3 catastrophic flooding events as a result of Tropical Storm Joaquin, Hurricane Matthew and Hurricane Florence. Residents of Horry County are vulnerable to storm surge, riverine and flash flooding. Although most of the county’s land value and tax base is located along the beachfront, less than 1% of the county is located within the coastal high hazard area. Most flood damage in Horry County has occurred as a result of major rain events, particularly along the Waccamaw River. 

The county has recently taken steps to improve flood resilience, including discouraging development of the floodplain and working to improve their CRS (community rating system) score for the National Flood Insurance Program. The county also recently commissioned an engineering firm to evaluate opportunities to increase the resilience of vulnerable areas. However, given the limitations of existing zoning ordinances and codes, challenges still remain in managing development to improve flood resilience.


The Project

Horry County Rising has identified two objectives for a Thriving Earth Exchange project. The first and primary objective is to analyze existing zoning ordinances and policies to protect communities from riverine flooding throughout the US. This analysis should include a summary of best practices and recommended actions to reduce flood risk in Horry County (or the City of Conway), SC. 

The second objective is to complete a benefit cost analysis of implementation of the recommended policy actions in Horry County (or the City of Conway), with a focus on opportunities to grow the economy, community protection, and equity. If necessary due to time/resource constraints, the second objective may be reserved for a phase 2 project. 

As a result of this collaboration, Horry County Rising will gain a better understanding of policy options available to mitigate riverine flooding risk in their community. This information will help the community better target future efforts, and provide critical data (e.g., associated costs and benefits) needed to advocate for flood resilience planning and policy.

About the Community

April O’Leary is a Flooded Family Advocate with Horry County Rising, located in Horry County, South Carolina. She will be supported by Harriet Festing, Executive Director of Anthropocene Alliance. 

As the community lead, April will serve as the main point of contact on the project and act as the liaison between the scientist(s) and the community. She will coordinate access to existing data, assessments, and relevant planning documents. With her knowledge of the local situation, April will also evaluate the feasibility of policies and actions proposed by the scientific partner(s).

Horry County Rising is a grassroots movement by the people of Horry County to help affected families mitigate their flood risk and vulnerability through education, empowerment, and engagement. Horry County Rising is a member of Higher Ground, an initiative of Anthropocene Alliance and the largest flood survivor network in the country. Higher ground has more than 45 chapters across 22 U.S. states, representing 35,000 flood survivors and their neighbors.

Project Team

Community Lead

April O’Leary is a Flooded Family Advocate with Horry County Rising, located in Horry County, South Carolina. (Photo and biography coming soon!)


Community Science Fellow

Pamela Braff is a Coastal Climate Extension Specialist at the Virginia Institute of Marine Science and Mid-Atlantic Regional Integrated Sciences and Assessments program. She provides tailored, decision-relevant information on the implications of climate variability and change to coastal communities and stakeholders throughout the Chesapeake Bay region. Her research is motivated by community needs, focusing on the resilience of coastal communities to climate change and sea level rise. 

Pamela is currently working on several initiatives to advance extreme weather and climate change resilience in the Chesapeake Bay region, including the development of localized, context-specific climate impact summaries and an inventory of existing climate resilience tools and resources. She also provides state agencies and local governments with technical support for coastal resource and flood risk management. 

Pamela received her B.A. in Marine Science from Boston University, an M.S. in Forest Resources and Environmental Conservation from Virginia Tech, and is a PhD candidate at the Virginia Institute of Marine Science.

Scientist Wanted

April is seeking a scientific partner to assist Horry County Rising with an analysis of landuse and stormwater ordinances to address riverine flooding impacts. In order to gain bi-partisan political support for flood mitigation policies and actions, the community would also like help in quantifying the costs and benefits of implementing the recommended actions in Horry County (or the City of Conway), SC.  This information would help April and Horry County Rising prioritize future advocacy efforts aimed at policy actions to mitigate current and future flood risk and support flooded families in Horry County.  

The community is open to the scientific partner(s) bringing in students to support this work. 


Thriving Earth Exchange asks all scientific partners to work with the community to help define a project with concrete local impact that they can contribute to as pro-bono volunteers and collaborators. This work can also position the scientists and communities to seek additional funding, together, for the next stage. 


Desired Skills and Expertise

  • Background in land use policy and zoning ordinance analysis, particularly with respect to riverine flooding and stormwater issues
  • Familiarity with climate and hydrology of coastal plain of South Carolina strongly preferred
  • Experience with GIS and ability to create maps to support advocacy efforts
  • Experience in community resilience and adaptation planning
  • Ability to translate science for a lay audience and discuss climate change in a non-divisive manner
  • Experience and/or desire to participate in community education, outreach and engagement
  • Relaxed, easy going personality with a good sense of humor 
  • Ability to visit the community in-person at least once

Interested in volunteering? Apply now!



The collaboration between the community and the selected scientific partner(s) should begin as soon as possible. The project should take about 12 months, with community outreach and education occuring during the last 3 months of the project. 

Collaborating Organization(s)

Thriving Earth Exchange has partnered with Higher Ground which supports grassroots flood groups across the country by helping them develop strategies for a sustainable future. Thriving Earth Exchange is working with several of their grassroots groups to connect them with scientists who can help them better characterize neighborhood-level flood risks and work effectively with local decision makers to mitigate those risks.