SAVE KIHEI

Slow Down in Flooded Streets

Slow Down in Flooded Streets: Why Driving Fast Through Floodwater Makes the Damage Worse

Following the recent Kona storm in Kihei, many residents are still dealing with flooded streets, waterlogged yards, damaged driveways, and erosion that will take weeks to repair. While the storm itself caused the initial flooding, the actions of drivers afterward can dramatically worsen the damage.

One of the most harmful behaviors seen during floods is driving too fast through standing water. What might seem like harmless splashing can create powerful wake waves that push water into homes, erode soil, damage landscaping, flood businesses, and endanger pedestrians.

Slowing down is not just polite—it is a practical and scientifically supported way to reduce damage and protect the community.

Floodwater + Speed = Artificial Wake Waves

When a vehicle drives through standing water, it behaves similarly to a boat moving through shallow water. The tires push water outward, creating wake waves that radiate to the sides of the road.

At higher speeds, these waves become significantly larger and more destructive.

Research on vehicle hydrodynamics shows that even a moderate-sized vehicle can generate waves several inches high, which are enough to:

  • Push floodwater deeper into homes and garages

  • Flood businesses that might otherwise stay dry

  • Erode soil, landscaping, and shoreline edges

  • Undermine driveways and foundations

  • Damage parked vehicles

In neighborhoods like Kihei where drainage systems are already overwhelmed, every passing vehicle can act like a small boat throwing wake against vulnerable properties.

According to flood-management researchers and transportation safety studies, wave height increases rapidly with vehicle speed, meaning that simply slowing down dramatically reduces the damage.

Sources:

Floodwater Can Hide Dangerous Hazards

Standing water on roads may look shallow, but it can conceal serious hazards such as:

  • Open storm drains

  • Washed-out pavement

  • Debris or sharp objects

  • Disabled vehicles

  • Pedestrians attempting to cross the road

During storms, people often must move between flooded areas on foot. A vehicle driving quickly through water can knock pedestrians off balance or completely drench them, creating a safety hazard and an unnecessary hardship during an already difficult time.

The National Weather Service warns that floodwater often contains debris, sewage contamination, and hidden dangers, making slow driving essential in affected areas.

Source:

National Weather Service Flood Safety
https://www.weather.gov/safety/flood

Fast Driving in Floodwater Is Dangerous for Your Vehicle Too

Beyond community damage, driving quickly through water also increases the risk of serious vehicle damage.

Automotive safety experts warn that floodwater can:

  • Cause hydroplaning, where tires lose contact with the road

  • Allow water to enter the engine air intake, causing hydrolock

  • Damage electrical systems

  • Reduce braking ability if water enters the brake components

Hydrolock can occur when water enters the engine cylinders, preventing pistons from moving and often destroying the engine instantly.

According to automotive engineering sources, even 6–12 inches of water can be enough to stall or seriously damage many vehicles.

Sources:

The Principle: “Turn Around, Don’t Drown”

Emergency agencies across the United States emphasize a simple rule during floods:

Turn Around, Don’t Drown.

This message from the National Weather Service highlights the dangers of driving through floodwater whenever possible.

More than half of flood-related fatalities occur in vehicles, often when drivers underestimate the depth or power of moving water.

Source:

National Weather Service Flood Campaign
https://www.weather.gov/safety/flood-turn-around-dont-drown

A Community Responsibility

Storm recovery in Kihei will take time. Flooded roads, damaged landscaping, and erosion are problems the community will be dealing with long after the storm clouds clear.

The simple act of slowing down while driving through standing water can make a significant difference.

Responsible driving during floods means:

  • Slow down to reduce wake waves

  • Avoid flooded streets unless necessary

  • Be alert for pedestrians

  • Slow down near stalled vehicles

  • Respect residents and businesses dealing with flood damage

Joyriding through flooded streets may seem harmless to some drivers, but in reality it amplifies the destruction caused by the storm.

A moment of caution behind the wheel helps protect homes, businesses, and neighbors.

The Bottom Line

Floodwater is already difficult enough for residents to deal with. Drivers can help—not harm—the recovery.

Slow down. Drive carefully. And remember that every splash has consequences.

When streets are flooded, responsible driving protects the entire community.

car driving too fast through flooded residential street creating waves that push water toward homes and property in Kihei Hawaii