Flood

When Floods Occur

  • Occur when a body of water rises to cover typically dry land.

  • Considered one of the most common natural hazards.

  • Account for 75% of federally declared disasters.

  • Can be local or widespread.

  • May develop either slowly or rapidly.

Causes of Floods and Flood Damage

  • Heavy rain leads to surplus water.

  • Spring snowmelt can cause water levels to rise.

  • Dam and levee failures can result in sudden flooding.

  • Low soil absorption or lack of percolation increases flood risk.

  • Growth of business and residential areas in flood-prone regions contributes to damage.

Factors Contributing to Flooding

  • Rainfall intensity affects the volume of water.

  • Rainfall duration impacts total water accumulation.

  • Topography influences water flow and accumulation areas.

  • Soil conditions determine how much water can be absorbed.

  • Ground cover (e.g., vegetation) affects runoff rates.

Flood Hazards

  • Heavy rainfall enhances issues related to:

    • Runoff: Excess water unable to soak into soil.

    • Absorption: Reduced capacity in developed areas.

    • Flood-control measures: May fail under heavy rain.

  • Ravine flooding can submerge downstream regions.

  • In urban settings, limited absorption leads to flash flooding.

Flood Risks

  • Every community faces some degree of flood risk.

  • Flood damage escalates with development in:

    • Coastal areas: More susceptible to storm surges.

    • Floodplains: Naturally prone to inundation.

Flood Preparedness

  • Understand the flood risk in your area.

  • Develop a flood evacuation plan.

  • Acquire flood insurance if situated in a floodplain.

  • Keep important documents in a waterproof container.

  • Use a portable radio for updates and emergency messages.

Protecting Property

  • Elevate essential utilities (furnace, water heater, electric panel).

  • Relocate furniture and valuable items to higher levels.

  • Install check valves to prevent backflow of water.

  • Make basement floors and walls waterproof.

If You Must Evacuate

  • Avoid walking, swimming, or driving through floodwaters.

  • Stay clear of bridges over swift water.

  • Keep away from waterways and watch for barricades.

  • Steer clear of storm drains and irrigation ditches.

  • Ensure family members stay together during evacuation.

After a Flood

  • Stay out of flooded areas to avoid hazards.

  • Reserve phone usage for emergencies.

  • Only drive in emergencies; wait for safe conditions.

  • Listen for authorities’ messages regarding safe return.

  • Be cautious of snakes and other wildlife that may enter homes post-flood.