Floods
The Natural Hazards in Arizona flood theme displays areas with high flooding potential as represented by the 100- and 500- flood zones determined by the Federal Emergency Management Agency (FEMA) digital flood insurance rate maps (DFIRM) database, dated May 2010.
Flood hazard data are currently unavailable for tribal lands in Arizona. To assess flood hazards on tribal lands, please seek out further information from the appropriate Tribal Division of Public Safety Department or Environmental Protection.
Source: Arizona Department of Emergency Management & Military Affairs
Last Updated: ?
Related Information
• Arizona Emergency Information Network – Flooding
• Get Prepared - Tips on how to prepare you, your family and business for flood hazards.
• FEMA – Flood Map Service Center: Search by Address
• National Weather Service – Flood Safety Tips & Resources
Mitigation Tips
Arizona has experienced flooding incidents of sufficient magnitude to prompt Presidential and/or Gubernatorial disaster declarations. Flooding causes damage and destruction of homes, businesses and personal financial resources.
You can take steps to protect yourself, your family and property before flood strikes by following these basic tips.
BUSINESSES/HOMES
• Elevate, floodproof, and/or relocate buildings/homes outside the floodplain or above flood elevation on a new foundation;
• Store important documents and irreplaceable objects to avoid damage;
• Elevate or relocate furnaces, hot water heaters, electrical panels and other equipment;
• Provide openings in foundation walls that allow floodwaters in and out, thus avoiding collapse;
• Build and install flood shields for doors and other building entries to prevent floodwaters from entering;
• Install backflow valves or plugs on drains, toilets and other sewer connections;
• Elevate, relocate or protect inventory, equipment and stored hazardous materials or other chemicals in areas that may be flooded;
• Acquire and demolish homes in the floodplain;
• Install sump pumps with backup power; and
• Purchase flood insurance.
PUBLIC WORKS/UTILITIES
• Protect or elevate ground mounted transformers;
• Elevate vulnerable equipment, electrical controls and other equipment at waste water treatment plants, potable water treatment plants and pump stations;
• For sewer lines in the floodplain, fasten and seal manhole covers to prevent floodwater infiltration;
• Protect wells and other potable water from infiltration or flood damage by raising controls/well pipe;
• Replace low bridges or other obstructions that may induce flooding of houses or businesses; and
• Move building contents to a higher floor or store outside the floodplain.
Further Reading
Source: Arizona Emergency Information Network Flooding
Floods are one of the most common hazards in the United States and constitute a real danger in Arizona. Floods can be local, impacting a neighborhood or community, or very large, affecting entire river basins and multiple states. Arizona has experienced flooding incidents of sufficient magnitude to prompt presidential and/or gubernatorial disaster declarations.
Some floods develop slowly, while flash floods can develop in just a few minutes and without visible signs of rain. Flash floods can occur within a few minutes or hours of excessive rainfall, a dam or levee failure, or a sudden release of water held by an ice jam. Flash floods often have a dangerous wall of roaring water carrying rocks, mud and other debris. Flash flooding is responsible for more fatalities—40 in Arizona since 1996—than any other thunderstorm-associated hazard.
Overland flooding occurs when waterways such as rivers or streams overflow their banks because of rainwater or a possible levee breach and cause flooding in surrounding areas. It can also occur when rainfall or snowmelt exceeds the capacity of underground pipes, or the capacity of streets and drains designed to carry flood water away from urban areas.
Be aware of flood hazards no matter where you live or work, but especially if you are in low-lying areas, near water, behind a levee or downstream from a dam. Even small streams, gullies, creeks, culverts, dry streambeds or low-lying ground that appear harmless in dry weather can flood.