Safety
Flash Flooding in the Rillito Near Tucson: When to Turn Back, and What to Do If You Stall
If the Rillito is running near Tucson, don't drive into any water on the road, even if the sky above you is clear. Rain in the mountains can send a flood down the wash miles away. If your car stalls near moving water, get out and climb to high ground if you safely can. Call 911 if you're trapped. Call for a tow only after the water has dropped.
Why can the Rillito flood when it isn't raining on you?
Most days the Rillito is a wide, dry bed of sand. It only carries water during floods. It forms east of town, where Tanque Verde Creek and Pantano Wash meet. From there it runs west for about 12 miles across Tucson's north edge, and it ends at the Santa Cruz River.
That means the Rillito collects water from a huge area. In a 1996 storm, the heaviest rain fell in the Santa Catalina foothills. Big flows then hit Tanque Verde Creek and the Rillito. Pima County's flood office puts it plainly: flash floods can move miles downstream and flood places that got no rain at all.
So you can be driving on River Road under a blue sky, with the storm far off to the east. The wash beside you can still rise fast. Don't judge the wash by the weather overhead. Judge it by the water in front of you.
Is the danger over now that monsoon season has ended?
No. The National Weather Service defines the monsoon as June 15 to September 30. But the Rillito's worst floods on record came outside that window.
- October 1983. Pima County calls it the largest flood of record in the Tucson area. About 6.5 to 7.5 inches of rain fell across the basin over 5 days. Rillito Creek took extensive damage.
- January 1993. Rain fell from January 5 to 19. The U.S. Geological Survey says record-setting volumes of floodwater ran down Rillito Creek.
- September 1996. A storm in the early morning flooded homes near River Road and Craycroft. It also flooded homes near Dodge and River Road, where Finger Rock Wash drains into the Rillito.
Look at those dates. The 1983 rain fell over 5 days, and the 1993 rain fell over two weeks. A slow, gray, rainy week can fill the Rillito as surely as a summer storm. Treat a wet October week like a monsoon afternoon.
How deep is too deep to drive through?
Any depth is too deep when the water is moving. The National Weather Service says 12 inches of rushing water can carry away most cars. Two feet can carry away SUVs and trucks. The Tucson office of the Weather Service adds that about 1 to 2 feet of water can float most vehicles.
The bigger problem is that you can't see the road under the water. Pima County warns that the pavement in a dip may be eroded or gone. A crossing that looks a few inches deep can drop off into a hole. Water also hides rocks, branches and other debris the flood carried in.
If you see brown water across the road near the Rillito, stop well short of it. Turn around and find a bridge or another route. Waiting it out in a dry spot is always the right call.
What does Arizona law say about driving around a barricade?
Arizona has a law for drivers who ignore flood barricades. Under A.R.S. 28-910, if you drive around a barricade onto a flooded road, you can be billed for the cost of the emergency response that pulls you out. The law also lets insurance companies leave that cost out of your coverage.
The cones and gates go up for a reason. A crew saw something you can't see from behind the wheel. Back up, turn around, and take the long way home.
Your car stalled near the wash. What now?
Your next move depends on the water. Look at it before you do anything else.
If water is rising around the car
- Unbuckle, and get out if you can do it safely.
- Move away from the wash, uphill, toward high ground.
- Don't walk through moving water. The Weather Service says 6 inches of fast water can knock over an adult.
- If you can't get out, call 911 and tell them you're in your car in floodwater.
A car can be replaced. Don't go back to it for your bag, your phone charger or anything else.
If the car died on dry ground near the wash
Turn on your hazards. If the car still rolls, coast it away from the low spot and onto higher, solid ground. Stay out of the dip in the road, since that's where water will cross first. Then call for help and keep an eye on the wash while you wait. If the water starts creeping toward you, leave the car and walk to higher ground.
When can you get the car towed out?
A tow truck can't drive into a running wash either. Flood rescue is a job for first responders, not a tow driver. Call for a tow once the water is gone and the road is open again.
What kind of help you need depends on where the car ended up:
- Engine took on water, or it won't start after the flood: don't try to crank it again. Ask for car towing to a shop.
- Wheels sunk in wet sand or mud right beside the road: a winch-out can pull the car back onto pavement.
- The car stalled on a dry street and only the battery is dead: a jump start may get you going.
- The car was carried down into the wash bed: that needs a heavy recovery crew. It's past what light-duty partners do, and we'll tell you so when you call.
How can you check the Rillito before you drive?
Pima County's Regional Flood Control District runs the ALERT network. It has more than 100 rain, stream and weather stations across the county. The data shows up in real time on the ALERT Desktop and ALERT Mobile maps.
Two of the stream gauges sit right on the Rillito. One is above Dodge Boulevard, and one is at La Cholla Boulevard. If you cross the Rillito on your commute, bookmark the mobile map. Check it before you leave on a stormy day.
For state highways and big closures, check AZ 511 too. And keep kids and pets off the Loop path and out of the riverbed after any rain. The Weather Service warns that washes flood easily and fast, even after light rain. The Rillito River Park runs along both banks from I-10 to Craycroft Road, so the path sits right beside the water.
How does Sentinel help after the water drops?
Sentinel Towing is a towing and roadside network. We don't own trucks. A vetted local partner tow company does the job. We text your price and lock it before anyone is dispatched. Then we text your driver's name, photo and truck, and check on you by text until help arrives. That's our Stay-With-You Promise. You can also track your truck on a map, so you can wait on high ground and still see it coming. For heat, I-10 and the rest of the metro, see our Tucson towing page.
Stuck right now? Call 1-888-TOW-1213, or request help online.
Rillito Flooding Questions
Is it the Rillito River or Rillito Creek?
Both names get used. Many people in Tucson say Rillito River. Pima County's flood records and stream gauges call it Rillito Creek. It's the same wash.
The water looks shallow. Can my SUV make it across?
Don't try. The Weather Service says 2 feet of rushing water can carry away SUVs and trucks. You also can't tell if the road under the water is still there. Turn around.
Will my insurance pay if I drove around the barricade?
Maybe not. Arizona's law makes you liable for the cost of the rescue. It also lets insurers leave that cost out. Read your policy, and don't drive past the barricade.
My car sat in floodwater. Should I try to start it?
No. Cranking an engine that took on water can make the damage worse. Have it towed to a shop and let a mechanic check it first.
Rules change, so check the official source before you rely on it. Sources: NWS Tucson: monsoon safety, NWS: Turn Around Don't Drown, Pima County: flooding myths and facts, Pima County: 1983 flood, Pima County: 1993 flood, Pima County: 1996 flood, Pima County: ALERT data, A.R.S. 28-910, AZ 511.
