The water usually arrives before anyone calls it a flood.
In Florence, it can start as a brown sheet sliding along a curb in historic West Florence, the kind residents know to watch because it has found the same low spots before. In Columbia, it can turn a Five Points intersection into a shallow, fast-moving pond before the rain has even stopped. No hurricane siren. No dramatic river crest. Just an ordinary South Carolina downpour meeting a drainage system built for another city, another climate, another century.
That is the quiet infrastructure story behind chronic flooding in Florence and Columbia: pipes too small, ditches too flat, inlets too few, culverts too old, and water with nowhere graceful to go.
The Florence flooding problem
Florence’s own stormwater planning language is blunt about the cause. As the city has grown, more land has been covered by rooftops, roads and parking lots, reducing the ground available to absorb runoff. Pipes that once handled “normal” rain are now too small in many areas, and older pipes lose capacity as sediment, age and deterioration work against them, according to the city’s Stormwater Master Plan.
The city says many flooding problems happen not during rare disasters but during smaller, more frequent storms, the kind people remember because they interrupt dinner, school pickup and the drive home from work.
The city’s Stormwater Master Plan put numbers behind what residents have seen for years. The plan identified 51 areas of concern across seven watersheds and found roughly 11,100 linear feet of trunklines surcharging under modeled 10-year and 25-year storms. Those storms are not abstract engineering exercises; they represent the kind of rainfall that exposes weak points in pipes, culverts, ditches and outfalls.
The map of trouble in Florence is not one single creek. It is scattered: clogged pipes, undersized culverts, inadequate inlets, eroded stream banks, debris, silt, vegetation and the city’s naturally flat terrain. Flat land does not give stormwater much help. When capacity runs out, water spreads.
That is why the Pennsylvania Street Stormwater Mitigation Project matters. It is not glamorous, but it is real. In August 2025, the South Carolina Office of Resilience announced construction on improvements along Pennsylvania, Coit, Preston, Lawson and West Sumter streets.
In Florence the work has moved past the planning stage and into the streets. City crews closed portions of Coit Street for several weeks beginning mid-June to install new stormwater pipe and drainage improvements, part of ongoing upgrades that also touch the Cedar and McQueen corridors. What once existed as lines on a master plan and numbers in a grant award is now orange barrels, detours, and fresh infrastructure going into the ground.
The project uses $5.1 million from the state resilience office through the ARPA Stormwater Infrastructure Program, with about $1 million in local match from Florence. Crews are expected to install nearly 1,300 linear feet of larger pipe, about 2,380 linear feet of drainage improvements and 39 new drainage boxes, with construction projected at five to seven months.
“We’re incredibly grateful to the South Carolina Office of Resilience for this significant investment in the City of Florence,” said City Manager Scotty Davis in August last year. “This grant will allow us to address longstanding flooding issues in Historic West Florence, improving the quality of life for residents and ensuring safer, more resilient infrastructure for years to come. We look forward to seeing the positive impact this project will bring to the community.”
That project also shows who often pays first when public infrastructure falls behind. The state resilience office said nearly three-quarters of residents in the Florence project service area are low- to moderate-income. In plain terms, repeated flooding is hardest on people least able to replace floors, miss work, elevate mechanical systems or wait months for repairs.
“The City identified that nearly three quarters of the project service area’s residents who will see benefits are considered low- to moderate-income. Furthermore, these stormwater enhancements will improve mobility for residents and first responders along three local arterial roads,” SC Chief Resilience Officer Ben Duncan said in August last year.
“Beyond a project’s ability to reduce the quantity and severity of flood hazard risks in a community, we also look at co-benefits.”
Columbia is not far behind
Florence is not alone. Columbia has lived for years with a different version of the same problem, only louder because some of the flooding happens in well-known public places. The city’s own list of flood-prone streets and intersections reads like a warning label for drivers: Adger and Devine, Blossom and Saluda, Blossom and Henderson, Main and Whaley, Wheat and Pickens, Harden and Santee, Gervais and Laurens, and more. Columbia Public Works tells drivers to avoid these areas during and immediately after heavy rain.
Five Points is the best-known case because it is both a drainage problem and a memory problem. The district is marketed as lively, walkable and historic. But before it became one of Columbia’s most recognizable business districts, the area was wetland. Rocky Branch once ran through the area before it was diverted around 1915 as the neighborhood took shape, according to The State’s reporting on the city’s proposed Five Points flood project. More than a century later, heavy rain still seems to remember the old geography.
Businesses in Five Points have adapted in ways that sound more like coastal storm preparation than urban commerce. The State reported that some keep sandbags and industrial vacuums ready, and at least one business owner previously described keeping furniture on risers to limit water damage from repeated storms.
Columbia’s proposed answer is enormous by local stormwater standards: a roughly $58.5 million plan to move stormwater through underground culverts from Martin Luther King Jr. Park toward Maxcy Gregg Park, where additional work would help collect and release water more slowly into Rocky Branch Creek.
“We’ve been studying Five Points for a long time,” said Columbia City Manager Clint Shealy, who oversees the city’s water and stormwater infrastructure. “This is a much larger, home-run-type solution”
City projections reported by The State show the concept could reduce the Five Points flood footprint by 55% during a 10-year storm. The city expects about $19 million through a South Carolina Emergency Management Division grant and has set aside about $15 million, leaving a large funding gap.
That is the strange math of stormwater: a flood that takes 40 minutes can require a 40-year fix.
Columbia looks for solutions, but progress is slow
Columbia has not been standing still. Its Capital Improvement Program is designed to fund projects across drinking water, wastewater and stormwater systems, typically through a five-year project list based on priority. The city’s Shandon Stormwater Improvements are already in design, with Cox and Dinkins contracted to evaluate drainage infrastructure from Melrose Heights to Devils Ditch near Owens Field Park and design improvements for frequent rainfall events. The work is expected to add storm drainage pipes and catch basins along two corridors through Rosewood and Shandon.
Another project, the Louisa Street Stormwater Retrofit and Sanitary Sewer Relocation, shows how flood work often overlaps with water quality, sewers and neighborhood equity. The project will rehabilitate a city-owned stormwater detention pond and relocate or replace sanitary sewer infrastructure on a city parcel in a lower-middle-income area near the terminus of Louisa Street. The council request listed a construction contract of $3,163,329.15, including a base bid and contingency, with completion estimated around mid-2027.
The pattern is similar in both cities. The old way was reactive: clear a ditch, replace a collapsed pipe, answer complaints, reopen a road. Florence’s planning history even points back to older drainage studies from decades ago, many recommendations never fully completed. The new way is more technical and more expensive: hydrologic and hydraulic modeling, GIS inventories, ranked project lists, utility fees, bonds, state grants, ARPA dollars and resilience language.
But technical planning does not make the water wait.
South Carolina’s resilience office says it has committed about $65 million statewide through its ARPA Stormwater Infrastructure Program. That sounds large until it is placed beside the cost of the work. Florence’s remaining conceptual stormwater needs exceed $70 million, according to the city’s Stormwater Master Plan. Columbia’s Five Points proposal alone approaches $60 million.
The pressure is not only local growth. The federal Fifth National Climate Assessment warns that the Southeast faces growing climate-related stressors, including extreme precipitation. That does not mean every flooded intersection can be blamed on climate change. It means old pipes designed around old assumptions face a harder future.
There is also a public safety cost that rarely appears in ribbon-cutting speeches. Flooded streets slow emergency vehicles. Standing water hides potholes, curbs and stalled cars. Businesses lose hours. Residents learn which roads to avoid. Children miss school. A stormwater failure is not just water in the street; it is time, money and confidence draining out of a neighborhood.
The encouraging part is that both Florence and Columbia now have the basic ingredients of a serious response: data, maps, prioritized projects and outside funding. The discouraging part is scale. A few million dollars can help one neighborhood breathe easier. It cannot erase decades of deferred drainage work across two growing cities.
So the question is not whether Florence and Columbia know what is wrong. Their own plans and project sheets show they do.
The question is whether South Carolina will treat chronic flooding as infrastructure failure before the next ordinary thunderstorm again proves the point.
