Why Chicago Basements Flood, and What to Do About It
Chicago has a lot to love. From irresistible food and incredible sports to a vibrant culture of art and music, the City of Chicago offers something for everyone. But there’s one thing that nobody loves about living in Chicago: flooded basements.
Unfortunately, basement flooding is a common problem for Chicago-area residents. Due to Chicago’s high water table, heavy rains and spring melts can easily overwhelm the city’s plumbing infrastructure. Without proper flooding mitigation, many homeowners will experience stormwater run-off backing up into their pipes.
From March to October, Chicago plumbers receive an influx of service calls for basement flooding and related issues, such as clogged sump pumps. However, as weather patterns change and rains become less predictable, it’s important to conduct proper maintenance on your home’s basement plumbing system – or even consider an overhead sewer conversion.
While you can’t stop the rain, you can protect your home from water damage during the rainy season. In this article, we’ll discuss why Chicago basements flood more easily than basements in other metropolitan areas and what you can do to prevent seepage and flooding.
Why Flooding is a Big Problem for Chicagoans
What makes flooding such a problem for homeowners in Chicago? Two reasons. First, Chicago has a combined sewer and storm drain system. Second, we have a high water table.
Combined Sewer System
Most cities have a separate sewer system for household wastewater and water from rain or melting snow. Chicago doesn’t. Instead, Chicago’s sewer system was designed to accommodate both types of water. Although this streamlines the city’s plumbing infrastructure, it can also backfire.
During heavy rains, the Chicago sewer systems reach capacity more quickly – and that rainwater has nowhere to go. Once the plumbing infrastructure gets overwhelmed, water can flow back up into floor drains, toilets, or sinks in your home. This is especially likely to occur if you have a basement.
Additionally, many Chicago neighborhoods have older sewer lines. These lines may be clogged with decades of debris, tree roots, or other blockages. Corrosion can also impact the flow-capacity of sewer lines in old homes. When there’s too much water after a storm, the excess pressure can strain these pipes and lead to back-flows.
NOTE: The Tunnel and Reservoir Plan (TARP), also known as the Chicago Deep Tunnel project, which is supposed to resolve this issue, is anticipated to be fully completed by 2029, with the final phase of the McCook Reservoir scheduled for completion in that year.
High Water Table
In geology, the term “water table” refers to the upper boundary of an area’s underground water supply. It’s the subterranean line where the unsaturated zone (the surface) and the saturated zone (groundwater) meet. In Chicago, the water table is unusually high – this means it’s closer to the surface. As a result, rainwater or runoff from spring melts doesn’t have very many places to go.
Think of the water table like a sponge. Water tables are absorbent, but only to a certain point. After periods of prolonged rain, the water table in Chicago simply can’t absorb any more moisture. However, this water has to go somewhere. Without adequate drainage systems, it often seeps into low-lying homes and buildings.
Flood Risks to Chicago Homeowners
Without a proper sump pump or ejector pump system, homeowners in Chicago are more likely to experience flooding in their basements and other subterranean structures like lower-level garages. In general, low-lying properties are more susceptible to issues like sewer back-flow problems. When it’s been raining heavily, this risk increases.
Other issues like obstructed sewer lines, brittle pipes, and inadequate drainage can lead to water damage during Chicago’s rainy season. When the city is overwhelmed with water, it often flows back into residential drains. Even with a working sump pump or ejector pump, too much water pressure from a storm may still overwhelm your home’s plumbing system.
Tips to Prevent Basement Flooding
The backflow from a storm can be a minor inconvenience, like a little dirty water flowing up into your bathtub, or a major disaster – like a flooded basement that damages your property and ruins your belongings.
Even if you haven’t had a problem with stormwater overwhelming your drainage system, it’s vital to assess your plumbing. Take preventative measures before it’s too late. As Benjamin Franklin once said, an ounce of prevention is worth a pound of cure.
Here are 4 tips to prevent basement flooding during Chicago’s rainy season:
Tip #1. Keep Sewer Lines Clear
The most effective way to prevent basement flooding in Chicago is regular sewer line maintenance. Although you can’t change the city’s infrastructure, you can ensure your own lines remain free from blockages. Fewer obstructions in your sewer line mean a decreased risk of backflow during storms.
Chicago homeowners should schedule regular hydro jetting or rodding to keep their lines clear. Regularly scheduled video inspection is also recommended. Plumbers can use state-of-the-art cameras to inspect your sewer lines for corrosion, tree roots, hidden debris, or other clogs that might affect backflow.
Tip #2. Maintain Your Sump Pump (and Ejector Pump)
To defend your basement from flooding, a functioning sump pump or ejector pump system is vital. Although sump pumps and ejector pumps operate differently, they fulfill the same purpose – moving water away from your basement and into the city’s drainage system.
Before the rainy season begins, test your sump pump or ejector pump. Clean the pump pits to prevent clogs, check valves, and ensure there is no damage to the unit. Many pump systems require electricity to work, so we also recommend having a backup battery to keep the pump working during power outages. Depending on the size of your property, you may also benefit from a secondary pump system for excess water.
Tip #3. Get an Overhead Sewer Conversion
Although sump pumps and ejector pumps are effective, one of the best ways to truly protect your home’s basement from flooding is through an overhead sewer conversion. An overhead sewer system raises your home’s sewer line above the basement level. By doing this, you prevent potential backflow from Chicago’s municipal sewer lines.
An overhead sewer conversion can be costly, however, it provides peace of mind and long-term protection from water damage due to flooding. With weather patterns changing, flooding may become more severe, so overhead sewer conversions are a worthwhile investment.
Tip #4. Other Backflow Mitigation Measures
Finally, homeowners in Chicago may consider other mitigation measures such as lift stations or downspout disconnection. Additionally, it’s recommended to check your property for cracks in the foundation. Seal these cracks to reduce water seepage during storms.
Partner with a Professional Plumber
While there are several steps you can take to prevent a flooded basement, there’s no substitute for the expertise of a professional plumber. A licensed plumber in Chicago understands the city’s infrastructure and regulations, weather patterns, and knows how to perform the right maintenance or upgrades to protect your home.
By maintaining your sewer lines and keeping a home drainage system in top-shape, you can prevent water damage caused by flooding during Chicago’s rainy season. And Rocket Plumbing is here to help! Call 773-299-1600 now or click here to schedule an appointment. We also offer coupons to make our services even more affordable.
