Basements flood in central Ohio for three main reasons: water that cannot drain through glacial till soil, a sump pump that fails or loses power, and sewer backup when the city system is overloaded in heavy rain. Phones are answered 24/7 and a crew is dispatched as fast as one is available.
Key takeaways
- Most central Ohio basements are full, so the water heater, furnace, electrical panel and floor drain all sit at the lowest point of the house.
- Franklin County sits on glacial till, and Pewamo soils have a seasonal high water table within about 30 cm (12 inches) of the surface from December to May.
- A sump pump protects a basement only while it has power, a working float and enough capacity for the inflow.
- A sewer backup must be reported to the city within 24 hours for the city to determine that rainwater caused it.
- The city's Project Dry Basement device stops sanitary sewer backups through a basement drain, not seepage through walls or windows.
- Standard homeowners policies generally exclude sewer and drain backup unless an endorsement or separate policy is added, so check your own policy.
Why do so many basements flood in Columbus?
Full basements are standard across central Ohio, so the lowest point of most houses holds the water heater, furnace, electrical panel, washer and floor drain. When water gets in, it reaches the equipment that matters most.
Central Ohio houses of nearly every era have full basements. In the older city neighborhoods the cellar is often a stone or rubble wall structure that weeps through its joints. In suburbs built from the 1980s on, the poured basement is commonly finished with carpet and drywall. The difference matters for cleanup, because a finished basement holds water inside walls and under flooring, while an unfinished one mostly loses its floor and the lower part of its walls.
Basement floods here usually come from a few routes that often overlap. Groundwater can push through the floor or walls, surface water can run toward the foundation after heavy rain, and sewage can back up through a floor drain when the sewer is overloaded. On 19 and 20 August 2026 the National Weather Service measured 4 to 7 inches of rain in the heaviest areas of Franklin and Licking counties, with significant overland and river flooding. Each route leaves different marks, so the crew checks which one happened before deciding what to remove and dry. Start with basement flooding cleanup if water is already in the house.
Why does the soil around a foundation hold so much water?
Franklin County sits on glacial till, a dense mix that drains slowly, and some of its soils keep a high water table for much of the winter and spring.
Bennington silt loam, formed in loamy glacial till, is somewhat poorly drained, with a perched water table about 15 to 30 cm (6 to 12 inches) down in normal years. Pewamo soils, found in depressions, are very poorly drained, and their seasonal high water table sits within about 30 cm (12 inches) of the surface from December to May. Those months are the window when foundation seepage and wall leaks are most likely to show up.
Clay that sheds rain slowly also explains why a heavy summer downpour can pond in a yard before it soaks in. Water that cannot leave the surface goes looking for a way down, often along the foundation wall. Soil type is not the only factor in any one basement, but it sets the baseline that grading, gutters and drain tile have to work against. A house on a low spot in the yard starts with less margin than one on a rise.
How does a sump pump fail, and what happens when it does?
A sump pump protects a basement only while it has power, a working float and enough capacity for the water coming in. When any one of those fails during a storm, the pit fills and the floor takes the water.
The usual failures are simple. Power goes out in the same storm that drives the water up, a float switch sticks or fouls, the discharge line is blocked, or the pump is too small for the inflow during a long wet spell. Many houses have one pump and no backup, so a single failure leaves the basement with no protection at all. The pit often looks fine from the top, which is why the water is found only after it has reached the carpet or the lowest shelf.
A battery backup or a generator keeps the pump working through a power cut, and an alarm gives early warning before the pit overflows. Fitting one is plumbing work, so a licensed plumber should do it. Plumbing work is licensed in Ohio: the state board licenses commercial plumbing contractors, and city building departments handle residential registration, so readers can ask any company which license it holds and check it with the issuing office. Once the water is out, the cleanup covers the pit area, the floor, the lower walls and anything that stood in the water. See sump pump failure cleanup for how that work runs.
What is a sewer backup, and how does the city's program help?
A sewer backup pushes contaminated water up through floor drains and low fixtures when the sewer system is overloaded. Columbus runs a program that installs a backflow device for eligible homes, but that device does not cover every route water can take.
Sewer backup is the signature basement call in Columbus. The city entered two consent decrees with Ohio EPA, in 2002 and 2004, to eliminate sewage backups into homes and overflows into the rivers in wet weather. The Division of Sewerage and Drainage answers that work through Blueprint Columbus, whose four pillars are sewer lining, roof drain redirection, sump pump installations and green infrastructure. Those are city projects, and they are separate from any cleanup a homeowner needs.
Project Dry Basement is a separate city program. For eligible single- and two-family homes, including rentals, the city pays for an approved backflow prevention device installed by its certified plumbing contractor. The device stops sanitary sewer backups through a basement drain only, so it does nothing about seepage through walls or windows. The city reported 1,814 devices installed as of its 2024 Public Utilities annual report. Eligibility questions go to the city. A backup must be reported to the city within 24 hours so it can determine that rainwater caused it, through the 24-hour Sewer Maintenance Operations Center at 614-645-7102 or by calling 311. Sewage is Category 3 water, so the cleanup is handled as contaminated work; see sewage backup cleanup and the Project Dry Basement guide.
What should you do in the first hour?
Stay out of standing water near outlets, the furnace or the electrical panel, and shut off the water at the main if you can reach it safely. Keep children and pets away from a sewer backup, and photograph everything before anything is moved.
Start with safety. If water is near the panel, the furnace or any plugged-in equipment, stay out of it and call the utility or an electrician before going in. If the water is clean supply water, shutting off the main stops the flow and limits the damage. A sewer backup is different: treat it as contaminated, keep children and pets out, and wash your hands after any contact with it.
Before you move furniture or pull up flooring, take photos and short videos of the damage, the water line on the walls and the pump or drain involved. Write down when you first noticed the water. Then call your insurer early. Phones are answered 24/7 at (833) 490-5225, and a crew is dispatched as fast as one is available. The crew can give you moisture readings and photos to share for your claim, and the price for the emergency stage is confirmed on site before any work begins.
How do downspouts, grading and drain tile work together?
Three things keep water away from a foundation: downspouts that discharge well clear of the wall, grading that slopes the soil down and out, and drain tile that carries groundwater away from the footing. If one fails, the other two carry more of the load.
A downspout that dumps at the foundation puts a steady stream of roof water against the wall, often right where the soil is least able to absorb it. Extending the discharge away from the house and keeping gutters clear reduces that load. Grading is the slope of the soil beside the wall. Soil that tilts back toward the house holds water against the foundation, while soil that falls away sends it toward the yard.
Drain tile, sometimes called perimeter drain tile, is a buried pipe along the footing that collects groundwater and carries it to a sump or an outlet. Many older Columbus houses were built without it, which is one reason their stone walls weep. Newer suburban houses often have it along with a sump pit. None of these fixes a failed pump or a backed-up sewer, so they work alongside backup power and a working sump rather than in place of them. Grading and drain work is contracting work, and the crew handles the drying and cleanup rather than the installation.
Does homeowners insurance cover a basement flood?
It depends on the cause and on your policy. A standard homeowners policy generally responds to sudden and accidental water damage, but generally excludes flood and sewer or drain backup unless an endorsement or separate policy is added.
The Ohio Department of Insurance lists water damage from sewer backup or a basement leak among typical exclusions on common homeowners forms, so that coverage usually depends on an added endorsement or rider. A long-term leak is generally treated differently from a sudden burst. Flood, meaning surface water, rivers and creeks, needs a separate policy, either through FEMA's National Flood Insurance Program or a private insurer.
Coverage is decided by your insurer under your own policy, so check your policy or ask your agent what applies to your home. The crew can document the damage for your claim, but it is your insurer that decides what is covered. If you disagree with how a claim was handled, the Ohio Department of Insurance takes consumer complaints at 800-686-1526. It reviews whether the insurer handled the matter within the policy terms, though it does not settle how much damage is worth.
What happens after the water is out?
Drying starts once the water is removed. The crew uses moisture meters and thermal imaging to find hidden wetness, sets air movers and dehumidifiers, and rechecks readings until materials are dry. Drying fast limits mold.
The water category decides how much material has to come out. Clean supply water is generally easier to manage than sewage, which is Category 3 under IICRC S500 guidance. Rising floodwater from a river or creek also falls in that most serious category, which is why the Scioto, the Olentangy and the east-side creeks matter for this work. EPA guidance is to dry water-damaged areas and items within 24 to 48 hours to prevent mold, and the crew works to that timing. For cost factors, see the cost guide.
A small moldy patch under about 10 square feet can often be cleaned by a homeowner, while larger areas, sewage-related mold and mold in the ductwork call for professional help. Ohio does not license mold remediation the way some states do, so ask any company what standard it works to. The IICRC S520 standard and EPA mold guidance are common references, and mold can trigger allergy and asthma symptoms in some people. Repairs such as drywall, trim and flooring are quoted separately after drying, once someone has seen the wet area.
Frequently asked questions
Is a wet basement the same thing as a sewer backup?
No. A wet basement usually means water is coming through the floor or walls from groundwater, surface water or seepage. A sewer backup means sewage or contaminated water is coming up through a floor drain or low fixture when the sewer system is overloaded. The two need different handling, and sewage is treated as Category 3 water, which is the most involved cleanup. The crew checks the source before deciding what to remove.
Does Columbus pay to fix a sump pump?
The city's Project Dry Basement program pays for an approved backflow prevention device for eligible homes, and it is installed by the city's certified plumbing contractor. It does not cover sump pump repair or stand-alone pump sales, and that work belongs to a licensed plumber. Eligibility is decided by the city, so check with the City of Columbus before assuming a home qualifies. Blueprint Columbus includes sump pump installations as a city project as well.
How quickly does mold start after a basement flood?
EPA guidance is to dry water-damaged areas and items within 24 to 48 hours to prevent mold. Drying fast is the most useful thing a homeowner can do while waiting for help. Mold can grow in materials that stay wet, including carpet pad, drywall and wood framing. If you see or smell mold after drying, ask the crew what standard it follows for any remediation.
Can I call at night if water is coming into my basement?
Yes. Phones are answered 24/7, and a crew is dispatched as fast as one is available. No arrival time can be promised, because it depends on how many calls are active and where the nearest crew is. Stay out of standing water near outlets and the panel while you wait, and take photos before moving anything.
Does the crew fix the pipe or the sump pump?
No. The crew does the water extraction, drying and cleanup, and it can help stop the water at the shut-off and board up an opening. Fixing a pipe, replacing a water heater or installing a sump pump needs a licensed plumber. Plumbing work is licensed in Ohio, and readers can ask any company which license it holds and check it with the issuing office. Columbus also requires plumbing contractors to be registered with the city.
Sources
- City of Columbus, Department of Public Utilities
- City of Columbus, Project Dry Basement program
- National Weather Service Wilmington
- City of Columbus Stormwater Drainage Manual
This guide is general information for Franklin County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.