South Carolina Flood Highlights Stormwater Management Issues

Historic flooding in South Carolina over the weekend highlighted one of the most challenging facets of municipal water management: stormwater control.

"We are at a 1,000-year level of rain," Governor Nikki Haley said at a news conference. "That's how big this is."

Dams failed throughout the region this week, “rattling residents who thought the worst had passed over the weekend,” the Associated Press reported on Tuesday. “Officials have said flooding could continue as stormwater drains down waterways.”

Blogger Jennifer Fitz wrote an opinion piece pointing to stormwater drainage circumstances as a source of the flooding. “The catastrophic flooding around the state is a combination of wet soil, plus over-full drainage systems (including controlled-release of full ponds and lakes), plus catastrophic failure of certain dams, unleashed on roads or bridges that don’t have the capacity to withstand a sudden massive increase in water flow,” she wrote.

“What we have is a stormwater system that essentially depends on the last storm being long gone before the next one shows up. inety-nine percent of the time, it’s a system that works well enough. We get ‘flooding’ but that just means ‘really big puddles.’ What you are seeing on the news is stuff we never, ever see,” she wrote.

She called on residents to consider these factors during the reconstruction ahead. “As we rebuild post-flood, something we need to acknowledge is that although this is the kind of thing that never, ever happens here — a true ‘perfect storm’ of rare weather conditions — South Carolina is also built up, at this writing, into a place unlike what lay here before,” she wrote.

Wastewater overflows were widespread during the storm. Mt. Pleasant Water Works (MPW) documented “record” overflows, according to a statement published on News 2. Mt. Pleasant took in over two feet of rain.

“Over the last two days crews have monitored the system and responded to areas that have reported overflows. MPW will begin the clean-up from overflows and testing of nearby waters for contamination. These overflows did not impact drinking water,” the statement said.

Residents in other areas were urged to boil their water. "Rising water from flooding can carry viruses, bacteria, chemicals and other submerged objects picked up as it moves through stormwater systems, across industrial sites, yards, roads and parking lots," the South Carolina Emergency Response Team said, per CNN.

Contamination is an ongoing threat in the region. "Rising water from flooding can carry viruses, bacteria, chemicals and other submerged objects picked up as it moves through stormwater systems, across industrial sites, yards, roads and parking lots," the South Carolina Emergency Response Team said, per CNN.

Flooding and rains in South Carolina associated with Hurricane Joaquin and heavy tropical weather patterns took the lives at least 11 people since the storm began, according to the Wall Street Journal. Seven of those people drowned, authorities said.

The rain diminished late Monday “after dumping more than 20 inches of rain in three days in the central part of the state, according to the National Weather Service. But officials warned that treacherous conditions could persist for days after at least nine earthen dams broke, many bridges flooded and large sections of roadway collapsed. Neighborhoods near several lakes were evacuated late Monday,” the newspaper reported.

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