The San Diego roads that flood in the rain, and what to do if you hit one
The repeat offenders are the Mission Valley river crossings (Fashion Valley Road, Avenida del Rio, Camino de la Reina, Mission Center Road), Sorrento Valley Road at Carmel Mountain Road, and low spots in Otay Mesa — and the rule is simple: never drive into water you can't see the bottom of.
- Water that floats a car
- 12 in, moving
- Fashion Valley flood stage
- 11.3 ft
- MTS routes rerouted
- 1, 6, 20, 41, 120
- Rule
- Turn around, don't drown
The short version
- NWS: 12 inches of moving water can carry away most cars, and 2 feet can carry away SUVs and trucks.
- Over half of flood drownings happen when someone drives into floodwater (CDC, via NWS).
- The San Diego River at Fashion Valley reaches flood stage at 11.3 feet; when it does, the Mission Valley crossings close.
- MTS has a pre-written "Rain Detour Plan" that reroutes buses 1, 6, 20, 41 and 120 when Fashion Valley Road and Avenida del Rio close.
- Report flooded roads and blocked drains in the City through Get It Done; in unincorporated areas, use the County's Tell Us Now app.
Most of San Diego drains beautifully, which is why the places that don't catch people off guard. A few crossings sit right on creek and river channels that were designed to overtop in big storms. In an El Niño winter, you should know them before you need a detour.
6 in
Fast-moving water that can knock over an adult
12 in
Rushing water that can carry away most cars
2 ft
Rushing water that can carry away SUVs and trucks
The usual suspects
Roads that have closed for flooding in recent storms
Closures reported during recent atmospheric-river storms (Fox 5 San Diego) and the MTS rain detour trigger. Not a complete list — any dip, underpass or creek crossing can flood.
Mission Valley floods because it is, literally, the San Diego River's floodplain — the malls and hotels sit where the river spreads out. When the river gauge at Fashion Valley approaches its 11.3-foot flood stage, the low crossings go under first. MTS has planned for it: its Rain Detour Plan kicks in "when the Fashion Valley Transit Center is open, but Fashion Valley Rd. and Avenida del Rio are closed at the San Diego River due to flooding," and sends buses around via Friars Road and SR-163.
If you come up on water
- 01
Stop before it
You can't judge depth or current from the driver's seat, and the road underneath may be gone.
- 02
Turn around
Take the detour even if the car ahead made it. Water rises fast in small San Diego watersheds.
- 03
If water rises around your car
Get out and move to higher ground if you can do so safely. Don't wait for the car to float.
- 04
Never walk into moving water
It's the second-leading cause of flood drownings after driving.
- 05
Report it
Call 911 for anyone in danger. For flooded streets and clogged drains, use Get It Done (City) or Tell Us Now (unincorporated county).
Before the storm
- Sign up for AlertSanDiego (or the Genasys Protect app) for evacuation and flood warnings.
- Know a route to work and school that avoids Mission Valley's river crossings.
- Check your wipers and tires — the CHP's standard rain advice is to slow down, turn headlights on and leave extra stopping distance.
- Park off the street in low spots if you can; flood insurance doesn't cover cars, your auto policy's comprehensive coverage does.
KEEP READING
SOURCES
Everything above traces back to one of these. Follow them — if one has changed and we haven't, that's our mistake, not yours.
- PrimaryTurn Around Don't Drown
National Weather Service · 2026-09-29
6 in / 12 in / 2 ft; over half of drownings in vehicles
- PrimaryRain Detour Plan 2
San Diego Metropolitan Transit System · 2026-09-29
Trigger and routes 1, 6, 20, 41, 120
Fox 5 San Diego
Closed roads; 11.3 ft flood stage at Fashion Valley
CalMatters · 2026-08-01
Chollas Creek 2024 flood
County of San Diego · 2026-09-29
AlertSanDiego, Tell Us Now app