A summer thunderstorm knocks out the power, the sump pump goes quiet, and within an hour there is water spreading across the basement floor. In the Chicago area this combination is common, because the same storms that overload sewers and saturate clay soil also bring down power lines. The instinct is to rush downstairs and start bailing, but a flooded basement with an uncertain electrical state is one of the more dangerous places in a house. This guide walks through what to do, in order: how to judge whether it is safe to go down at all, how to handle the electrical panel, how to use a generator without creating a new hazard, and what to check before the lights come back on.

Why an Outage Makes a Basement Flood More Dangerous

Many Chicago-area basements depend on electricity to stay dry. A sump pump moves groundwater out of the pit, an ejector pump lifts waste from a basement bathroom or laundry up to the sewer line in homes with overhead sewers, and many of these systems have no backup. When the grid drops during a storm, these pumps stop at exactly the moment the ground and the sewer system are most overloaded.

At the same time, the basement is where the electrical service usually lives. In older bungalows, two-flats, and frame cottages across the city and inner-ring suburbs, the main panel, the meter, and sometimes an older fuse box sit on a basement wall, with outlets, extension cords, chest freezers, and the furnace blower all near floor level. Rising water plus wiring that may be energized, or that may re-energize without warning when the utility restores service, is the core risk.

Heavy rain can also overwhelm the combined sewer system managed by the Metropolitan Water Reclamation District (MWRD), pushing water up through floor drains. That water is contaminated, which adds a health hazard on top of the electrical one.

Step 1: Decide Whether It Is Safe to Enter

Before anyone goes downstairs, stop at the top of the stairs with a flashlight and look. Do not assume that because the house is dark, the basement is dead. Power can return at any moment, a neighbor's generator can backfeed lines, and battery or solar systems may still be live. Do not enter the basement if any of the following are true:

  • Water is touching or close to outlets, power strips, extension cords, the electrical panel, or any appliance that is plugged in.
  • You hear buzzing, crackling, or popping, see sparks, or smell burning plastic.
  • You smell natural gas (a rotten-egg odor). Leave the house and report it from outside.
  • The water is deeper than your ankles and you cannot see the floor, drains, or debris under it.
  • The water is coming up through a floor drain or toilet and appears to be sewage.
  • Walls are bowing, the floor is heaving, or there are new cracks appearing in the foundation.
  • You would have to stand in water to reach the electrical panel.

If none of those apply and the water is shallow, it may be reasonable to go down wearing rubber boots, but treat every wire and appliance as live. If you are unsure, the safer choice is to wait upstairs and let a licensed electrician or the utility confirm the power is off.

Step 2: Shut Off Power Safely, or Leave It to the Utility

The goal is to make sure the basement circuits stay off even when grid power returns. How you do that depends on where the panel is and how dry the path to it is.

  1. If the panel is on a dry floor and you can reach it standing on dry ground, wear rubber-soled boots, keep one hand at your side, and switch off the main breaker first, then the individual basement breakers. With an older fuse box, pull the main fuse block.
  2. If you would have to step into water, or the panel itself is wet, do not touch it. Report the situation to your electric utility (ComEd serves most of the Chicago area) and ask for the service to be disconnected at the meter or the pole.
  3. Never use a wooden broom handle or similar tool to flip a breaker from a distance while standing in water. It is a common internet tip, but it does not make the situation safe.
  4. Tape a note on the panel saying the power was shut off because of flooding, so no one in the household flips it back on before an inspection.

In a multi-unit building, the basement often holds several meters and panels. If you rent, let the owner or building manager know what you see before touching shared equipment.

Step 3: Use a Generator Without Creating New Hazards

A portable generator can get a sump pump running again, but it is also the source of many outage-related injuries. The main dangers are carbon monoxide, backfeeding, and electrocution through wet cords.

  • Run the generator outdoors only, well away from windows, doors, and vents. Never run it in the basement, an attached garage, a breezeway, or under an open window, even with the door open. Public-health guidance commonly recommends at least 20 feet of distance.
  • Have working carbon monoxide alarms on every level, including the floor above the basement. CO is odorless, and symptoms such as headache, dizziness, and nausea are easy to mistake for stress or fatigue.
  • Never plug a generator into a wall outlet or dryer receptacle to power the house. This backfeeds the utility lines and can electrocute line workers or neighbors. Whole-house connections require a properly installed transfer switch or interlock.
  • Use outdoor-rated, heavy-gauge extension cords that are long enough to reach without splices, and keep every connection out of the water. Plug the pump into a GFCI-protected outlet or cord where possible.
  • Do not lower a pump cord through standing water to a generator if the plug or connection would sit in the water. Route cords along walls or overhead.
  • Refuel only after the generator has cooled, and store fuel outside the living space.

If the basement panel has been under water, powering a sump pump directly from a generator cord is much safer than trying to energize any house circuit.

Step 4: Check Gas Appliances and Contamination

Many Chicago basements house the furnace and water heater, and floodwater can extinguish pilot lights, soak burners and controls, or shift gas lines. If water reached the bottom of either appliance, leave it off and have it inspected before relighting. If you smell gas at any point, leave immediately and report it from outside.

Assume water that entered through a floor drain, toilet, or laundry standpipe is sewage-contaminated (Category 3). Keep children and pets out, wear gloves and boots, and avoid touching your face. Water that came in as clean groundwater through the sump pit can turn contaminated quickly once it sits and picks up debris. Porous materials that sewage water soaks, such as carpet, pad, and cardboard boxes, generally cannot be cleaned and are discarded.

Step 5: Remove Water Gradually Once It Is Safe

Once the power is confirmed off in the basement and the space is safe to enter, take photos of the water level and affected belongings for your own records, then start removing water.

  1. Restore the sump pump first using a generator or battery backup, if the pit and pump are accessible and the cord path is dry.
  2. Pump out deep water in stages. When the surrounding soil is saturated, pulling all the water out at once can leave the foundation walls with water pressure on only one side. FEMA guidance suggests removing standing water gradually over several days when the ground outside is still waterlogged.
  3. Move wet contents upstairs or outside, starting with items that can still be saved, such as photographs, documents, and furniture with intact frames.
  4. Start air movement as soon as power can be used safely, since mold can begin to grow on wet drywall, carpet pad, and wood within a day or two.

For a fuller timeline of what to prioritize, the guide to the first 24 hours after a flood covers drying, documentation, and what to discard.

Step 6: Before the Power Comes Back On

When the grid is restored, the basement circuits you shut off should stay off until someone qualified has looked at them. Water leaves corrosion and silt inside breakers, outlets, and junction boxes that can cause shorts or fires days later.

  • Have a licensed electrician inspect the panel, breakers, outlets, and any wiring that was submerged before re-energizing.
  • Treat submerged outlets, GFCI devices, and breakers as needing replacement, not just drying.
  • Have the furnace, water heater, and any ejector or sump pump motors checked before running them on house power.
  • Discard or have inspected any plugged-in appliance whose motor or control board went under water, including washers, dryers, chest freezers, and dehumidifiers.

A Hypothetical Example: One Storm, Three Roles

The following scenario uses fictional people to show how these steps fit together.

Dana Reyes, an owner-occupant in a brick two-flat on the Northwest Side, loses power during an evening storm. Her upstairs tenant, Marcus Hale, texts that he hears water in the basement. Dana checks from the top of the stairs: about two inches of water, the sump pit overflowing, and an extension cord for a chest freezer lying on the floor. The panel is on the far wall.

Because she would have to walk through water past a plugged-in cord, Dana does not go down. She reports the situation to the utility and asks Marcus to keep his family out of the basement. The next morning, with service disconnected at the meter, she runs a generator in the backyard to restart the sump pump on a single heavy-duty cord. A fictional electrician, Priya Nair, later replaces two submerged outlets and a corroded breaker before the basement circuits are switched back on. No one stood in water near live wiring at any point, which is the whole point of the sequence.

Preparing for the Next Outage

Outages and flooding tend to arrive together in this region, so the most useful steps happen before the next storm:

  • Add a battery backup sump pump or, where municipal water pressure allows, a water-powered backup. The battery backup sump pump guide explains the trade-offs.
  • Install a high-water alarm in the sump pit so you know the pump has stopped before water reaches the floor.
  • Keep cords and power strips off the floor and mount them on walls in basements prone to water.
  • Ask an electrician about raising basement outlets or adding GFCI protection on basement circuits during any renovation.
  • Have a transfer switch or interlock installed if you plan to rely on a generator.
  • Know where your main breaker is and keep a flashlight with fresh batteries near the basement door.
  • Consider a backwater valve or overhead sewer if floor drains back up during heavy rain, since outages often coincide with sewer surcharging.

If water is already in the basement and the electrical situation is unclear, the referral line at 312-801-1888 can connect you with local basement flood help in the Chicago area.