Flash floods that occur each year pose a significant threat to Filipino motorists. We are the lucky ones considering that flash floods have only caused damaged to property, unlike in the United States where an average of 75 lost their lives due to these severe weather conditions.
Areas such as the Lagusniland in Manila, Banawe in Quezon City and the Maysilo in Mandaluyong City are low lying areas that have poor drainage systems and are notorious for flash floods. For motorists caught in a heavy rainfall, the single worst decision that you can make is driving your vehicle into floodwaters of unknown depth. It is easy to miscalculate the depth of floodwaters particularly at night and in poorly lit road networks. Driving through rains and flooded streets are made even worse by unmarked road repairs which are prevalent among erring contractors.
According to the Metropolitan Manila Development Authority (MMDA), flash flood events occur in a localized area, with some severe flooding affecting passage of vehicles and the roads a danger to motorists in a matter of hours.
According to the MMDA, here are points to consider during heavy rain and when floods are imminent:
• Six inches of water will reach the bottom of most passenger cars, causing loss of control and potential stalling.
• A foot of water will float many vehicles.
• Two feet of rushing water will carry away most vehicles, including SUVs and pickups.
In a report conducted by the U.S. Geological Survey, water 1 foot deep typically exerts 500 pounds of lateral force on a vehicle.Once your vehicle is floating, the floodwater becomes your steering wheel. If that water is moving, your vehicle could be swept away, tipped on its side or flipped.
Rising water can enter your vehicle in a manner of minutes, even seconds.The best advice we can give is to never drive through flood waters of unknown depth. As the National Weather Service has campaigned for years: “Turn around, don’t drown!”
If you are stuck in your vehicle underwater, you need to act quickly:
• Find a pocket of trapped air, usually against the rear window or roof.
• Roll a window down slowly, take a deep breath and be ready to swim.
• If the window won’t open, break the window with a rescue tool (Swiss Army knife, for example).
Driving through floods is a big mistake
Don’t be too confident when wading through floods even if you are driving an SUV. If floodwater is powerful enough to float and/or trap your vehicle, trying to wade through it is a recipe for disaster. Just six inches of flowing water can knock you off your feet. If you slip and fall face first, you might drown before you come to and is particularly dangerous situation for babies and small children.
Flowing at just 15 kph throug water exerts the same force per unit area as air blowing at EF5 tornado wind speeds, according to Dr. Greg Forbes, severe weather expert for The Weather Channel. Water moving at 30 kph has the pressure equivalent of wind blowing at 790 mph, faster than the speed of sound .Forbes says the fastest flood water speeds are thought to be around 67 mph, which may occur in steep, elevated terrain.
In general, awareness of the weather can save your life in a flash flood. You can monitor flooded areas by listening to the radio by way of weather bulletins or find a weather app on your smartphone to receive flood watches, warnings and what areas to avoid. Next time there is a risk of flash flooding, take it seriously. Stay safe, drive cautiously and be defensive on the road. Don’t be the topic of the six o’clock news.