From the Upstate to the coast, flooding and stormwater management serve as a challenge nearly all municipalities in South Carolina experience; and stormwater runoff is considered the greatest threat to the nation’s water supply, according to the Clemson University Cooperative Extension.
Many cities and towns around the state are drafting or refreshing their existing stormwater master plans. Two such communities taking the next step forward with their stormwater master plans are the City of Florence and the Town of Sullivan’s Island.
Florence completed and adopted its stormwater master plan in December 2025.
“We took it a little bit further than just your standard master plan,” said Clint Moore, Florence assistant city manager, noting that the city partnered with the SC Office of Resilience to assist in funding the planning process.
“We looked at the overall area, our growth area, where we expect to grow over the next 20 years, but then we expanded it to include a hydrological study to confirm our ‘boots-on-the-ground’ observations, where we have stormwater issues, and it helped us identify some of the areas that we weren’t entirely aware of,” he said.
What elevated the plan, Moore said, was making water quality an important component, leading not just to “recommendations of projects, but also policy changes that we can make in the future, to one — not only handle our stormwater runoff as development increases and some of the strategies with addressing that, and two — how we can better improve the overall water quality that is so often impacted by stormwater runoff within our area.”
While the Florence area watersheds feed into the Lynches and Great Pee Dee rivers, the city aims to make sure that the water flowing into them is as clean as possible.
With the previous master plan dating to the 1970s, the city took about two years to complete its new plan, including rounds of surveying, the hydrological study, and asset management work. The city hosted public meetings to garner community input and buy in, as well as meetings with community organizations.
“It is very important to work with your residents, because they’re dealing with this every day,” Moore said. “They are our eyes and ears out there; we can’t have city staff everywhere all the time.”
Identifying responsible parties was another key part of the master planning process. The city made a point of assembling all of the entities involved in stormwater to illustrate how complex even a single project can be.
“Unlike most utilities, dry or wet, stormwater is a system that knows no boundary; it is not really clear who’s responsible for it,” he said. “It goes where it wants to naturally go. With that, you have so many entities that it affects and are responsible for different infrastructure and watersheds.”
The master plan functions as a 20-year working plan for identified stormwater projects, and since its adoption, the City of Florence has received grant funding and taken out a bond to begin three of them.
In the Lowcountry, the Town of Sullivan’s Island is no stranger to stormwater issues like flooding.
“The town really started focusing on in-house, town-managed stormwater management about five years ago,” said Town Administrator Joe Henderson. “Council made the decision to pursue any grant funding possible to fix the stormwater system in the [SC Department of Transportation] right of way, and so that’s what we’ve done.”
Henderson said that the town pursued multiple grants to receive the necessary funding for not only the repairs to the system, but also for research studies in order to create the stormwater master plan and the town’s first resiliency plan. The town applied for Federal Emergency Management Agency Building Resilient Infrastructure and Communities grants in the 2020 and 2021 cycles.
“Based on the recommendations from those plans, we have really mobilized and moved forward on the improvement work that is needed throughout the island,” he said. “One of the things that came out of our stormwater master plan was a recommendation to fund and develop formally a stormwater division, a group of full-time employees that would have the equipment and the skillset to go out and actually clean out pipes, clean out ditches, use heavy equipment like vac trucks to be able to clean out these structures in the right of way.”
Once the 2020 FEMA BRIC grant was approved, the town contracted Seamon Whiteside & Associates as its project managers.
“Part of that project was a survey of the entire stormwater system, going through identifying what is in disrepair, what needed to be replaced,” Henderson said. “They provided recommendations for how we could go out and get grant monies, how we can use our reserves to fund some of the improvements, and what the town needs to do going forward in maintaining our inventory and inspection of all stormwater systems.”
Of the 18 project areas identified in the master plan, Henderson said that the approach will be incremental. One of the largest grants that the town received three years ago was from the SC Rural Infrastructure Authority: a SC Infrastructure Investment Program grant in the amount of $10 million, which Henderson said is about 80% complete. With that funding, the town has embarked on repairing and replacing infrastructure at four different basins across the island: stations 31, 28.5, 25 and 16.
The town also received a FEMA Hazard Mitigation Assistance grant for projects around Sullivan’s Island Lighthouse at stations 18, 18.5 to 19, which have begun construction, Henderson said. A second FEMA HMA grant will fund improvements at stations 18.5 and 25, which Henderson said is in the planning phase.
In addition to state and federally funded grant projects, the town is embarking on its own stormwater infrastructure improvements out of its operating budget and various reserves, notably at Stith Park next to Town Hall, where flooding frequently occurs. The town procured a contractor for the project, which will continue through late summer.
Yet another town-funded project is underway on the eastern side of the island.
“We’re making some improvements on the eastern side of the island on the marsh where we have lots of flooding impacts — not just storm surge but also tidal impacts,” Henderson said, sharing that the project entails re-digging a ditch that goes out to deep water, replacing the outfall and installing a new check valve.
“Some of the neighborhoods around Station 9.5 flood on a regular basis, so we’re hoping that that project will improve the situation over there. So really across the board, we’ve got projects going on and we’re trying to knock them out,” he said.
Stormwater management is undoubtedly a critical component to maintaining strong, resilient communities. Municipalities throughout South Carolina are investing in the research and the surveying needed to identify existing and potential problem areas, and to mitigate stormwater runoff and flooding as development continues to increase statewide.