Hurricane Helene and the Congaree: September 2024 Came Within a Foot of 2015 All Over Again

Hurricane Helene made landfall on Florida's Big Bend coast as a Category 4 hurricane on September 26, 2024, with sustained winds of 140 mph. But Helene's most catastrophic impact wasn't at the coast — it was hundreds of miles inland across Georgia, South Carolina, and especially North Carolina.

After landfall, Helene moved rapidly northward, dumping historic rainfall across the southern Appalachians. Asheville, NC received more than 13 inches of rain, causing the French Broad and Swannanoa Rivers to flood catastrophically. Entire towns in western North Carolina were washed away.

For Columbia, Helene's rainfall wasn't as extreme as October 2015 — the city received 6-8 inches over two days, compared to 15+ inches in 2015. But Helene's rainfall fell across a much larger geographic area, including the entire Congaree River watershed extending into North Carolina.

The result: all of that water — from rainfall across thousands of square miles in North Carolina, Georgia, and upstate South Carolina — flowed downstream into the Broad River, Saluda River, and ultimately the Congaree River that runs through Columbia. The Congaree became a massive conveyor belt of floodwater, rising to levels not seen since 2015.

On September 27, 2024, the Congaree River at Columbia crested at 30.26 feet — the second-highest level ever recorded, exceeded only by the October 2015 flood when the river reached 31.17 feet.

To understand the significance, consider the Congaree's flood stages:

• 10 feet: Flood stage — minor flooding begins
• 15 feet: Moderate flooding — low-lying areas flood
• 19 feet: Major flood stage — widespread flooding
• 25 feet: Riverland Park begins evacuating
• 30 feet: Catastrophic flooding imminent
• 31.17 feet: October 2015 record crest

At 30.26 feet, Helene brought the Congaree to within 12 inches — one foot — of matching the worst flood in Columbia history. National Weather Service forecasters initially predicted the river might exceed 31 feet, which would have broken the 2015 record. Columbia residents braced for catastrophe.

Fortunately, the crest fell just short. But the experience terrified thousands of Columbia families who rebuilt after 2015, invested in flood insurance, and believed they wouldn't face another catastrophic flood for decades. Helene proved that assumption was dangerously wrong.

Riverland Park, a residential neighborhood built in the Congaree River's floodplain in southeast Columbia, evacuated on September 26-27, 2024, as the river approached 30 feet. More than 100 residents left their homes, many of them for the second time since the 2015 flood.

Riverland Park sits at an elevation that floods when the Congaree exceeds 25-26 feet. The neighborhood was built in the 1970s and 1980s in an area known to be in the river's 100-year floodplain — meaning it has a 1% chance of flooding in any given year. In reality, it has flooded multiple times: 2015, 2016, and now 2024 during Helene.

During Helene, Richland County emergency management issued mandatory evacuation orders for Riverland Park on September 26 as the river was forecast to crest above 30 feet. Residents packed vehicles with belongings, pets, and valuables, not knowing if their homes would survive.

Many Riverland Park homes have flood insurance — it's required for federally-backed mortgages in flood zones. But insurance doesn't eliminate the trauma of evacuation, the disruption to life, or the months-long restoration process after water recedes. For some residents, Helene was the final straw. Several families decided to sell and move to higher ground rather than face a third or fourth evacuation.

On September 28, 2024, as the Congaree River crested, a 200-foot power transmission tower collapsed into the river near Riverland Park. The tower, which carried high-voltage lines across the Congaree, had stood for decades but couldn't withstand the force of floodwater and debris piling against its foundation.

The collapse cut power to thousands of Dominion Energy customers in southeast Columbia and created a hazardous situation with live electrical lines submerged in floodwater. Emergency crews were forced to de-energize the lines and establish safety perimeters.

The tower collapse became a visual symbol of Columbia's infrastructure vulnerability to extreme flooding. Just as the Columbia Canal breached in 2015, the transmission tower failure during Helene demonstrated that critical infrastructure built decades ago was not designed for the river levels Columbia is now experiencing.

Repairs took weeks. Dominion Energy constructed a temporary power line across the river while planning a permanent replacement tower with a foundation designed to withstand 100-year flood levels. The cost exceeded $5 million.

While Helene's impact on Columbia was primarily from the Congaree River, Gills Creek — the tributary that devastated Forest Acres in 2015 — also rose significantly during the storm. Though it didn't reach 2015 levels, the creek's rise triggered PTSD for hundreds of Forest Acres residents who rebuilt after the thousand-year flood.

On September 26-27, Gills Creek rose to moderate flood stage as 6-8 inches of rain fell across its watershed. Water entered yards and approached homes along Trenholm Road, Covenant Road, and other Forest Acres neighborhoods that flooded catastrophically in 2015.

Residents who had invested tens of thousands of dollars rebuilding after 2015 — and purchased flood insurance they never thought they'd need — watched anxiously as water crept toward their properties. Many staged vehicles on higher ground, moved belongings to second floors, and prepared to evacuate.

This time, the water stopped short. Gills Creek crested below the levels that cause major flooding. But the experience was traumatic nonetheless. Families who believed 2015 was a once-in-a-lifetime disaster realized they could face another Gills Creek flood at any time. The psychological toll — the constant anxiety during every heavy rain — is a hidden cost of living in a flood-prone area.

After 29 dams failed during the October 2015 flood, South Carolina launched a comprehensive dam safety review and repair program. Richland County identified dozens of high-risk dams requiring upgrades or removal. Millions of dollars were spent reinforcing earthen dams and improving spillway capacity.

During Hurricane Helene, those upgrades were tested. Fortunately, no major dams failed. The improved spillways and reinforced embankments handled the rainfall and runoff without catastrophic breaches.

However, Helene revealed that not all dams have been repaired. Several older neighborhood dams remain classified as "high hazard" — meaning their failure would cause loss of life — but lack funding for upgrades. These dams are monitored during storms, but monitoring doesn't prevent failure.

The South Carolina Department of Health and Environmental Control (DHEC) estimates that more than 200 high-hazard dams across the state still need significant safety improvements. The cost exceeds $100 million. Until these dams are repaired or removed, Columbia-area residents downstream remain at risk during extreme rainfall events.

After the 2015 flood devastated thousands of uninsured homes, flood insurance uptake in Columbia increased significantly. But nine years later, the majority of Columbia-area homes still don't have flood insurance.

According to FEMA data, fewer than 15% of South Carolina homes outside high-risk flood zones carry flood insurance. In Columbia, that means thousands of properties along Gills Creek, near the Congaree, and in low-lying areas have no financial protection if flooding occurs.

The reasons are familiar: homeowners assume they're not at risk, don't want to pay premiums ($400-$800/year for properties outside flood zones), or mistakenly believe their homeowners insurance covers flooding (it doesn't).

Hurricane Helene didn't cause catastrophic flooding in Columbia, so the insurance gap didn't result in massive uninsured losses. But if Helene had crested just one foot higher — matching or exceeding 2015 levels — thousands of Columbia families would have faced total financial loss with no insurance recovery.

The next major flood won't wait for you to buy insurance. Policies have a 30-day waiting period, meaning you can't purchase coverage when a storm is approaching. If you live in Columbia and don't have flood insurance, get a quote today. It's the single most important step you can take to protect your home.

Since 2015, the City of Columbia has invested millions of dollars in stormwater infrastructure improvements: upgraded drainage systems, improved retention ponds, better pump stations, and expanded flood monitoring. These improvements have reduced flooding during moderate rain events.

But during extreme events like Helene — or a repeat of October 2015 — Columbia's stormwater infrastructure remains inadequate. The systems are designed for 10-year or 25-year storms, not 100-year or 1,000-year events.

Gills Creek, the deadliest flooding source in 2015, still lacks the channel capacity to handle extreme rainfall without overflowing. Neighborhoods built in the 1950s-1970s have undersized drainage pipes that can't handle modern rainfall intensities. Low-lying areas near the Congaree have no protection against river flooding.

Fixing these infrastructure gaps would cost hundreds of millions of dollars — far more than the city can afford without federal and state assistance. Until that funding materializes, Columbia remains vulnerable to catastrophic flooding from the next extreme weather event.

Hurricane Helene was the second time in nine years that Columbia faced catastrophic flooding. The October 2015 flood was labeled a "thousand-year event" — statistically expected once every 1,000 years. Helene came within a foot of matching it just nine years later.

Climate scientists are clear: extreme rainfall events are becoming more frequent and more intense due to climate change. Warmer air holds more moisture, creating atmospheric conditions that produce record-breaking rainfall totals. Hurricanes are intensifying more rapidly and maintaining strength further inland.

For Columbia, this means "thousand-year floods" will happen more often than once every thousand years. The statistical models that created flood zone maps and risk assessments are based on historical data that no longer reflects current conditions.

Homeowners, city planners, and insurance companies must adjust to a new reality: extreme flooding is no longer rare. It's the new normal. Columbia will face more Helene-level events, and eventually, another 2015-level catastrophe. The question isn't if — it's when.

Hurricane Helene was a warning. Columbia came within 12 inches of repeating the worst disaster in state history. The next storm might not stop short. Here's what every Columbia-area homeowner must do now:

1. Buy Flood Insurance: Even if you're not in a FEMA flood zone. Policies outside flood zones cost $400-$800/year and can save you from total financial loss.

2. Know Your Flood Risk: Use FEMA's Flood Map Service Center to check your property's flood zone. But understand that flood zones only show river flooding — they don't account for urban flash flooding from heavy rain.

3. Create an Evacuation Plan: Know your evacuation route, have a destination identified, and prepare a go-bag with essentials. Don't wait for mandatory orders — leave early if you're in a flood-prone area.

4. Document Your Home: Take photos/video of every room and your belongings. Store documentation in the cloud. This makes insurance claims exponentially easier after flood damage.

5. Establish a Restoration Relationship: Identify a licensed, local restoration company before disaster strikes. After major floods, contractors are booked for months. Having an established relationship ensures faster response.

6. Elevate Critical Systems: If you're in a flood-prone area, elevate HVAC systems, water heaters, and electrical panels above potential flood levels. This can save tens of thousands in replacement costs.