In August 2022 a storm with hail dropped several inches of rain across the eastern Twin Cities metro over a few hours. Flash flooding followed in Inver Grove Heights, and it showed how little warning heavy rain gives.
Key takeaways
- The August 2022 storm brought hail and several inches of rain across the eastern Twin Cities metro, and flash flooding reached the city.
- Police rescued two people from their vehicles during the flooding.
- The city says heavy rain and snowmelt can lead to flooding, erosion, road damage and costly emergency repairs when drainage is not maintained.
- Flash flood water is treated as contaminated because it carries street runoff, soil and debris.
- Fast extraction limits how far water spreads into walls and floors.
What happened in Inver Grove Heights in August 2022
A storm with hail dropped several inches of rain across the eastern Twin Cities metro over a few hours, and flash flooding followed in the city.
Police rescued two people from their vehicles. One driver said hail covered her windshield so she could not see that the road was flooded, and the water rose to her car windows.
Police said a few people had to climb onto the tops of their cars.
The lesson for homeowners is speed. Water came faster than drivers could react, and the same speed applies to garages, window wells and lower levels.
What flash flooding does to a garage and a lower level
A garage door is a wide opening, so flash flood water can enter all at once. From the garage, water moves under interior doors into finished space, and from window wells it can pour into a lower level.
- Stored boxes, tools and cardboard soak up water and should be moved off the floor first.
- Drywall in a garage wall wicks water upward from the slab.
- Window wells that fill can spill through the glass or the frame.
- Floor drains in a garage or lower level can push water up when the storm sewer is full.
How the city moves rain and snowmelt
Pipes, ponds and ditches
Rain and snowmelt from roofs, driveways, streets and open land are directed into a managed system of pipes, ponds, ditches, culverts and drainageways. That system carries water to ponds, wetlands and ultimately the Mississippi River.
Rural areas rely on ditches, culverts, ponds and natural channels, and many of those ponds and ditches are maintained by the city.
What the city says about aging parts
The city says portions of the stormwater system are aging and that current funding has contributed to a growing backlog of deferred maintenance.
It also says that without regular maintenance, heavy rain and snowmelt can lead to flooding, erosion, road damage and costly emergency repairs.
None of that predicts where water will go in a given storm. It does explain why a ditch or storm inlet near a house deserves attention before the rain starts.
Keeping stormwater separate from home plumbing
The city treats water and sewer utilities, which manage water used inside a home or business, as separate from the stormwater utility, which manages rain and snowmelt across the community.
That split matters during a flood. A storm inlet on the street belongs to the stormwater system, while a leaking pipe inside the house is a plumbing repair.
Why flash flood water is not like a plumbing leak
Water from a burst pipe starts clean. Flash flood water has crossed streets, driveways and yards before it reaches a house.
That journey is why a storm and river flood cleanup job starts with different assumptions than a supply pipe failure.
- It carries soil, oil, lawn chemicals and sewage from overloaded drains.
- Porous materials such as carpet, pad and insulation that soak in it are usually removed.
- Hard surfaces can be cleaned and treated.
- It often arrives with mud, which has to be shoveled out before drying.
How hail and heavy rain combine
The August 2022 storm brought hail along with the rain. Ice and leaves packed into gutters, downspouts and storm inlets can keep rain from draining, so water spills where it should not.
After a hailstorm, a walk around the property to clear inlets and window wells is a useful first step before the next rain.
The first steps inside a flooded home
Stay safe
- Keep out of standing water until power to the area is off.
- Never drive into water covering a road; the 2022 rescues began with vehicles in floodwater.
- Move people and pets to higher ground.
- Photograph the high water mark before anything is moved.
Start the removal
Pumps and water extraction units pull standing water from garages and lower levels.
Removal starts early because the longer water sits, the further it moves into drywall, trim and framing.
What extraction and drying involve
After extraction, mud and debris are removed and wet materials are sorted. Carpet, pad and soaked insulation are usually discarded; concrete, block and framing are cleaned, treated and dried.
Moisture meters steer the work. Dehumidifiers and fans stay in place until the readings settle at a dry reference.
The storm flood cleanup page lays out the steps for a home that took water from a storm.
Odor control matters as much as water removal. Flash flood water leaves a smell that clings to porous materials, which is another reason they are removed.
Insurance and records
Photographs, a list of damaged items and the readings from each drying visit help a claim go smoothly.
Flash flooding is often handled differently from other water damage in a policy, so the wording is worth reading before a storm.
Getting ready before the next heavy rain
Heavy rain events do not give a second warning. A short list done on a dry day is worth more than a plan made during a storm.
The Inver Grove Heights water damage pages list the services available for each type of loss.
- Clear leaves and debris from storm inlets and ditches near the property.
- Check that downspouts discharge away from the foundation.
- Test the sump pump if the home has one, and know where the main electrical shutoff is.
- Move stored items off the floor in garages and lower levels.
Questions
What happened in Inver Grove Heights in August 2022?
A storm with hail dropped several inches of rain across the eastern Twin Cities metro over a few hours, and flash flooding in the city led police to rescue two people from their vehicles.
Where do rain and snowmelt go in the city?
They are directed through pipes, ponds, ditches, culverts and drainageways to ponds, wetlands and ultimately the Mississippi River.
Is flash flood water contaminated?
Yes. It carries street runoff, soil and debris, so soaked porous materials are usually removed and hard surfaces are cleaned and treated.
Is stormwater the same utility as water and sewer?
No. The city treats the stormwater utility as separate from water and sewer utilities, which manage water used inside a home or business.
Should a flooded garage be pumped right away?
Standing water should come out as soon as it is safe, because it spreads into walls and floors. Power to the area has to be off first.
How does hail make flooding worse?
Ice and debris can block gutters, downspouts and storm inlets, so rain runs where it should not.