What should you do after a flood or storm puts water in your home or building?

Stay out of standing water until the power to that area is off, photograph everything, and call your insurer. Treat floodwater that rose from outside as contaminated (IICRC Category 3) and keep children and anyone with asthma away. Standard homeowners policies exclude flood, so check whether you carry a separate NFIP or private flood policy.

Flood and storm losses look alike on the floor but are handled differently. Water that rises from the ground, a creek or an overwhelmed storm sewer is a flood. Rain that comes through a roof or window torn open by wind is storm damage. That difference drives the cleanup method, the safety precautions and which insurance policy responds.

How hard can one storm hit DuPage and Will County?

Very hard, and fast. Our summers bring slow-moving thunderstorms that can drop several inches of rain on one town while the next town over gets far less. Finished basements, sump pumps and older storm sewers in many suburbs mean that kind of rain finds its way indoors quickly.

On July 29, 2016, the National Weather Service Chicago office documented extremely slow-moving storms along the I-88 corridor that brought flash flooding to DuPage, Kane, DeKalb and Cook counties. The DuPage River at Bolingbrook reached a top-10 crest in its roughly 20-year record.

Why basements take the first hit

When a storm sewer surcharges or the ground saturates, water finds the lowest openings: window wells, floor drains, foundation cracks and a sump pit that can't keep up. That is why basement water damage is the most common call after a summer downpour in towns like Darien and Bolingbrook.

Our guide to basement flooding after heavy rain covers the emergency steps and why local basements flood.

Is floodwater always Category 3?

Rising floodwater is. The ANSI/IICRC S500 standard defines Category 3 water as grossly contaminated, able to carry pathogenic or toxigenic agents, and lists "rising water from rivers or streams" and sewage among its examples. Water that crossed a lawn, a street and a floor drain on the way in should be handled the same way.

Storm water that enters from above is not automatic. In a 2026 position statement, the S500 consensus body clarified that top-down water, wind-driven rain and other weather-related water are not automatically Category 3. The restorer inspects, gathers information and then makes a preliminary determination of the category.

What the category changes

The same position statement quotes the standard's rule for contaminated losses: with Category 2 or 3 water, remediation should happen before restorative drying, with contamination controls and proper worker protection. In practice, that means removing saturated porous materials such as carpet, pad and the lower section of drywall, then cleaning before drying begins.

Sewage is its own hazard. See our guide to sewage backup cleanup and Category 3 water.

How do you stay safe during flood cleanup?

Most flood injuries happen in the water, not in the cleanup. The National Weather Service warns that 6 inches of fast-moving water can knock over an adult, 12 inches can carry away most cars, and 2 feet can carry away SUVs and trucks. Never drive into a flooded underpass, however familiar the road.

Wear heavy gloves, boots and protective clothing if you must go in. Don't run household fans in a basement until you know whether the water was clean, because they can spread contamination.

Does insurance cover flood and storm damage?

Storm damage often is covered; flood usually is not. The Insurance Information Institute's facts about flood insurance explain that standard homeowners and renters policies exclude flood. Coverage comes from the National Flood Insurance Program or a private insurer, with a 30-day waiting period before most NFIP policies take effect. NFIP limits are $250,000 for the home's structure and $100,000 for contents.

Windstorm and hail are named perils on standard homeowners forms, so a roof opened by wind is normally a homeowners claim. Sewer backup needs its own endorsement. Commercial property owners should check their commercial flood and business income terms. Policies vary, so confirm with your agent or the Illinois Department of Insurance, and see our insurance claim assistance page for help with documentation.

What does professional flood cleanup involve?

1. Safety survey. The restorer checks power, gas, structural soundness and contamination before crews enter.
2. Determine the category. Inspection and the water's source decide whether Category 3 precautions apply.
3. Extract water and mud. Truck-mounted or portable extractors remove standing water and silt; emergency water removal shortens everything that follows.
4. Remove unsalvageable porous materials. For Category 3 losses, saturated carpet, pad, insulation and drywall are typically bagged and removed.
5. Clean and treat surfaces. Remaining structure is cleaned before drying, as the S500 calls for with contaminated water.
6. Dry and dehumidify. Air movers and dehumidifiers bring materials to measured drying goals; see structural drying and dehumidification.
7. Document and rebuild. Photos, readings and removal records go to the insurer before repairs start.

Storm damage from above

When wind or hail opens a roof, the first job is keeping the next rain out. Our guide to storm damage board-up and roof tarping explains what to document before temporary repairs.

From our Lisle headquarters, certified technicians handle flood and storm cleanup across DuPage and Will County, including Naperville and Glen Ellyn, as part of our water damage restoration and commercial water damage restoration services.

Questions about a past storm? Contact our team. If water is coming in now, call 24/7 at (630) 241-1111.