Written by Alex Lira, Emergency Preparedness Specialist

Flooding is one of the most frequently occurring natural disasters in Wisconsin. It is also one of the top causes of weather-related fatalities across the U.S.¹^,² However, with proper planning and preparation, you can greatly reduce flood-related risks for you and your loved ones.

Warning Signs

Flooding can happen quickly and without much warning, so it helps to watch for changing conditions near rivers, streams, and any low-lying areas in your vicinity. 

Examples of flood warning signs include:

• Rising water near roads, lawns, yards, and/or buildings.
• Water pooling on and covering roads that were previously passable.
• Rapidly changing river conditions during the spring thaw or after heavy rainfall.
• Ice piling up near bridges or bends in rivers, which can possibly trigger an ice jam flood.¹^,²

The National Weather Service (NWS) advises people to enable weather alerts, monitor weather forecasts for potential threats, and use a National Oceanic and Atmospheric Administration (NOAA) Weather Radio during heavy rain and storms to receive alerts about any potential flash floods.²

How to Prepare

There are many steps you can take now to help keep you, your loved ones, and your property safe from floods²:

• Families should have a communication plan, a place to meet on higher ground, and an emergency kit with food, water, medications, money, and a charged power source.
• Make sure sump pumps work and have battery backup in case of a power outage.
• Homeowners should consider flood insurance.
• Protect critical powered systems by elevating or flood-proofing appliances and electrical equipment whenever possible.
• Ensure you have professionally installed backflow or check valves to help prevent floodwater from backing up into and blocking drains and sewer lines.

What to Do During Flooding

If local officials issue a warning or evacuation order, leave immediately and follow the safest route to higher ground.¹^,² Never drive through floodwater. This is because you cannot know for certain how deep the water is, whether the road has washed out, or how dangerous the current may be.¹^,²

Stay away from flooded areas and never walk into floodwater. Floodwater can contain bacteria, chemicals, agricultural runoff, sewer waste, sharp objects, and downed power lines.²

Private Wells and Drinking Water

Flooding and heavy rain can contaminate private wells. The Wisconsin Department of Natural Resources says well owners should assume the water is contaminated if flooding occurs or if the water changes in taste, color, or sediment levels after heavy rain.³

If that happens, stop drinking the water. Instead, use an alternate source such as bottled water, and contact a local certified water tester to sample the water before drinking it.³ Even wells without obvious flooding can be contaminated, so testing is important after major rain and flooding events.³

Know Your Flood Risk

The Risk Assessment Flood Tool is an interactive tool that allows users to see updated flooding risks and other potential hazards within their specific location. This resource can help communities understand if their property or local food sources are at risk of damage due to flooding and identify any other hazards that may apply to them.⁴

Flooding can occur even outside mapped high-risk zones, so it is important to pay attention to local conditions and weather forecasts. The best protection is to combine official flood maps with real-time weather alerts and local preparedness planning for your specific community.¹^,²^,⁴

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Sources 
1. Flood safety tips and resources. National Weather Service. Accessed April 22, 2026. https://www.weather.gov/safety/flood 

2. Flood Safety Awareness Week in Wisconsin. National Weather Service. Accessed April 22, 2026. https://www.weather.gov/mkx/FloodSafetyAwarenessWeekinWisconsin

3. DNR warns that heavy rain and flooding can contaminate private wells. Wisconsin Department of Natural Resources. Published April 16, 2026. Accessed April 22, 2026. https://dnr.wisconsin.gov/newsroom/release/121791

4. Wisconsin Risk Assessment Flood Tool. Wisconsin Department of Health Services. Accessed April 23, 2026. https://dhsgis.wi.gov/dhs/raft/