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Flood

Flash Flood

  • Causes most of the direct weather-related fatalities.
  • A person can be taken away in as little as 6 inches of water – a car in as little as 2 feet of water.
  • Can occur during or within a few hours after extended rainfall.
  • Communities particularly at risk are those located in low-lying areas, near water, or downstream from a dam.
  • The rapid flooding of streams, valleys, and other flood-prone areas can occur during any month of the year but are more frequent during the months of October through April.
  • Since flood damage is almost never covered by homeowners insurance, flood insurance is important for people living in high-risk flood zones.

Before a Flood

Hawaiʻi’s wet season is typically between October to March. Try some of these tips before the season starts, especially if you live in a flood-prone area:

  • Avoid building in a floodplain unless you elevate and reinforce your home.
  • Gather important documents such as your flood insurance policy. Flood losses are not covered under normal homeowners’ insurance policies.
  • Keep a supply of sandbags to direct floodwater away from your home.
  • Seal walls 1 to 2 feet above baseboards with waterproofing compounds.
  • Listen to the radio or television for information. Be aware of streams, drainage channels, roads, and other areas known to flood suddenly.
  • Be aware that flash flooding can occur quickly and without warning. Be prepared to evacuate and move immediately to higher ground. Do not wait for instructions to move.
  • Secure your home and elevate essential items. Turn off utilities if instructed to do so. Disconnect electrical appliances and do not touch electrical equipment if you are wet or standing in water.

During a Flash Flood

  • Listen for news reports to learn whether the community’s water supply is safe to drink. You may need to boil tap water before drinking.
  • Avoid floodwaters; water may be contaminated by oil, gasoline, or raw sewage. Water may also be electrically charged from underground or downed power lines. Keep away and report downed power lines to the power company.

After a Flood

  • Be aware of areas where floodwaters have receded; Roads may have weakened and could collapse under the weight of a car.
  • Return home only when authorities indicate it is safe.
  • Stay out of any building if it is surrounded by floodwaters as there may be hidden structural damage to the foundation.
  • Service damaged septic tanks, cesspools, and leaching systems as soon as possible. Damaged sewage systems are serious health hazards.
  • Clean and disinfect everything that got wet. Mud left from floodwater can contain sewage and chemicals.
  • Be sure to dry areas that may have been affected by flood water. Areas like drywall, carpet and flooring exposed to moisture may encounter mold growth later.