Weather & Natural Hazards
Flooding & flash floods
Flooding is survivable, and the rule that saves the most lives is the simplest one there is. Learn to read how deep is too deep, tell a flash flood from a river flood, and know exactly what to do if water reaches your car.
Flooding is one of the nation's deadliest weather hazards, and many flood deaths happen in vehicles — people who drove into water that was deeper or faster than it looked. The rule that saves the most lives is the simplest: Turn Around, Don't Drown.
The single most important rule
Turn Around, Don't Drown
Turn Around, Don't Drown: never walk or drive into floodwater. You can't tell how deep it is, how fast it's moving, or whether the road beneath it has washed away. Turn around and find another route — every time.
Why water beats the car
How deep is too deep
As a rule of thumb (not an exact promise for every vehicle): about 6 inches of fast-moving water can knock an adult off their feet; about 12 inches can float many cars; and 18 to 24 inches will carry off most vehicles, including trucks and SUVs — and the roadbed underneath may already be gone.
Fast and local, or slow and forecast
Two kinds of flooding
There are two kinds of flooding. A flash flood is fast and local — water can rise in minutes, especially in the Ozarks, at low-water crossings, and in small creeks and dry washes after heavy rain. River flooding is slower — it builds over days as a river rises, and the Weather Service forecasts it river by river. (Floating or near a river? See the Rivers & Tubing hub for low-water crossings and reading river levels.)
If you spend time on or near the water, the Rivers & Tubing hub goes deeper on low-water crossings and how to read river levels before you go.
What the warnings mean
Two flood warnings, two responses
Flash Flood Warning
A Flash Flood Warning means move to higher ground NOW — the water can come up faster than you can react.
River Flood Warning
A River Flood Warning means follow the forecast, the evacuation instructions, and the road closures for that specific river. A slow-rising river doesn't mean everyone must instantly climb to high ground — follow the location-specific instruction the warning gives.
If water reaches your car
If your car is trapped in floodwater
If floodwater traps your vehicle, never step out into rapidly moving water — it can sweep you off your feet and pull you under. If fast water is around the car, STAY INSIDE. If water starts rising INSIDE the car, get onto the roof and call or signal for help. Move on foot only if the water around you is shallow and still. And never drive around a barricade — it's there because the road ahead is unsafe or gone.
On foot and afterward
Other flood rules
Don't camp or park in low spots or dry creek beds when heavy rain threatens. Stay out of floodwater on foot — it can be deep, fast, full of debris, and even electrically charged by downed lines. After a flood, wait for officials before you go back, and never trust a flooded road.
A benchmark Missouri remembers
Missouri's great flood
Missouri's benchmark is the Great Flood of 1993. The Mississippi River at St. Louis crested at 49.58 feet on August 1, 1993 — about 20 feet above flood stage. Across the multi-state disaster, damage ran to roughly $15 billion and about 50 people died.
A money note
A money note, not advice: standard homeowner's and renter's policies usually do NOT cover flood damage — that's a separate policy through the National Flood Insurance Program (NFIP) or a private insurer, and NFIP coverage typically has a 30-day waiting period before it starts (with limited exceptions). Ask a licensed agent before flood season, not during it.
Next
A flash flood can rise faster than any forecast — so make sure the alerts will reach you (a NOAA Weather Radio wakes you for a 3 a.m. warning), and if you spend time on the water, float trips start at the Rivers & Tubing hub.
When a warning is issued
Missouri Porch explains the hazard; the National Weather Service and your local officials call the warning.
Last checked: 2026-06-18. Hazards repeat, so most of this page stays true year to year — but alert-product names, the year's stats, and the ShakeOut date can change. Check the date above, and always follow the live National Weather Service warning and your local officials over anything written here.
This site explains and prepares — it is not a live warning. When a warning is issued, follow it and your local emergency officials immediately; they have the live picture. This is not insurance, legal, or medical advice. In any life-threatening emergency, call 911.
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