Flash Flooding & Floods

FLASH FLOODING is the #1 WEATHER-RELATED KILLER in the UNITED STATES!

Flash floods occur because of intense rainfall for a long duration. They 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 can roll boulders, tear out trees, destroy buildings and bridges and scour out new channels. Flash flood-producing rains can also cause mud slides.

Most flash flooding is caused by slow-moving thunderstorms or thunderstorms repeatedly moving over the same area.

Flash floods generally affect low lying areas near creeks, streams and rivers. When ground is saturated or frozen it is unable to absorb the intense rainfall; and, thus, it spreads out over the ground. It rises quickly, but will also fall quickly once the rain has let up or stopped.

The rule for being safe in a flooding situation is simple:
HEAD FOR HIGHER GROUND AND STAY AWAY FROM FLOOD WATERS!

Listen for distant thunder, runoff upstream could be headed your way.

When a flash flood WATCH is issued, be alert to signs of flash flooding and be ready to evacuate on a moment's notice, if you are in a flash flood prone area.

Know your area, also when you are camping or near streams.

When a flash flood WARNING is issued for your area, or the moment you realize that a flash flood is imminent, act quickly to save yourself. YOU MAY ONLY HAVE SECONDS!

Know your environment and if you are prone to flash flooding.

Move household items and vehicles to higher ground, if threatened by flooding.

Keep your automobile fueled; if electric power is cut off, gas stations may not be able to operate pumps for several days.

Know your evacuation routes. Plan ahead where you could stay when flooding threatens your home.

Assemble a disaster supplies kit and include rubber boots, rubber gloves and other essential items.

Listen to NOAA Weather radio or local radio and television.

IN YOUR AUTOMOBILE:

• NEVER drive through flooded roadways!
• If the vehicle stalls, leave it immediately and seek higher ground. Rapidly rising water may engulf the vehicle and its occupants and sweep them away. Remember, it's better to be wet than dead!
• Do not attempt to cross flowing streams
• Be especially cautious at night, when it is harder to recognize flood dangers.
• Do not camp or park your vehicle along streams and washes, particularly during threatening conditions.
• If you are advised to evacuate, do so immediately.
• Move to a safe area, before access is cut off by flood water.
• Continue to monitor your local radio and television stations.

HOW CAN A FOOT OR TWO OF WATER COST YOU YOUR LIFE?
Water weighs 62.4 lbs per cubic foot and typically flows downstream at 6 to 12 miles an hour.

When a vehicle stalls in the water, the water's momentum is transferred to the car. For each foot the water rises, 500 lbs of lateral force are applied to the car.

But the biggest factor is buoyancy. For each foot the water rises up the side of the car, the car displaces 1,500 lbs of water. In effect, the car weighs 1,500 lbs less for each foot the water rises.

TWO FEET OF WATER WILL CARRY AWAY MOST AUTOMOBILES.

Floods

FLOODING
Flooding is a longer term event and may last a week or more.

RIVER FLOODING:
Flooding along rivers is a natural and inevitable part of life. Some floods occur seasonally when winter or spring rains, coupled with melting snows, fill river basins with too much water, too quickly.

St Charles County is prone to flooding, as two of its three borders are major rivers. To the east, the Missouri River which has limited levee protection, to the north, the Mississippi River. St Charles County is also impacted by the Illinois River, which flows into the Mississippi River at Grafton, and the Cuiver River along the Lincoln County/St. Charles County lines.

URBAN FLOODING:
As land is converted from fields or woodlands to roads and parking lots, it loses its ability to absorb rainfall. Urbanization increases runoff 2 to 6 times over what would occur on natural terrain. During periods of urban flooding, streets can become swift moving rivers, while basements can become death traps as they fill with water.

Flood Safety: Same principals apply as above.

AFTER the FLOOD:

• If fresh food has come in contact with flood waters, throw it out.
• Boil drinking water before using. Wells should be pumped out and the water tested for purity before drinking.
• Seek necessary medical care at the nearest hospital. Assistance will be available through local emergency agencies.
• Do not visit disaster areas. Your presence might hamper rescue and other emergency operations. You also be mistaken as a possible looter.
• Electrical equipment should be checked and dried before being returned to service.
• Use flashlights, not lanterns, torches or matches, to examine buildings. Flammables may be inside.
• Report broken utility lines to appropriate authorities.

TIPS FOR THE CARE OF WATER-DAMAGED FAMILY HEIRLOOMS AND OTHER VALUABLES
Following a disaster, people often lose family heirlooms and other valuables to water damage. The Federal Emergency Management Agency (FEMA) has obtained general information/recommendations from the American Institute for Conservation of Historic and Artistic Works (AIC) and the National Institute for the Conservation of Cultural Property (NIC) for homeowners regarding the recovery of water-damaged belongings.

• If the object is still wet, rinse with clear, clean water or a fine hose spray. Clean off dry silt and debris from your belongings, with soft brushes or dab with damp cloths without grinding debris into objects.
  
  
• Air dry objects indoors, if possible. Sunlight and heat may dry certain materials too quickly, causing splits, warpage and buckling.
• The best way to inhibit growth of mold and mildew is to reduce humidity. Increase air flow with fans, open windows, air conditioners, and dehumidifiers.
  
  
• Remove heavy deposits of mold growth from walls, baseboards, floors, and other household surfaces, with commercially available disinfectants. Avoid the use of disinfectants on historic wallpapers.
  
  
• If objects are broken or begin to fall apart, place all broken pieces, bits of veneer and detached parts in clearly labeled open containers. Do not attempt to repair objects until completely dry or, in the case of important materials, until you have consulted with a professional conservator.
  
  
• Documents, books, photographs and works of art on paper may be extremely fragile when wet. Use caution when handling. Free edges of prints and paper objects in mats and frames, if possible. These should be allowed to air dry. Rinse mud off wet photographs, with clear water; but, do not touch surfaces. Sodden books and papers should also be air dried, or may be kept in a refrigerator or freezer until they can be treated by a professional conservator.
  
  
• Textiles, leather and other "organic" materials will also be severely affected by exposure to water and should be allowed to air dry.
  
  
• Remove wet paintings from the frame, but not from the stretcher. Air dry, face up, away from direct sunlight.
  
  
• Furniture finishes and painted surfaces may develop a white haze or bloom from contact with water and humidity. These problems do not require immediate attention. Consult a professional conservator for treatment.
  
  
• Rinse metal objects exposed to flood waters, mud or silt with clear water and dry immediately with a clean, soft cloth. Allow heavy mud deposits on large metal objects, such as sculpture, to dry. Caked mud can be removed later. Consult a professional conservator for further treatment.

Because the information given above is general, FEMA, AIC and NIC strongly recommend that professional conservators be consulted as to the appropriate method of treatment for historic objects. Professional conservators may be contacted through the FREE Conservation Services Referral System of the American Institute for Conservation of Historic and Artistic Works, 1717 K Street, NW, Ste. 301, Washington, D.C. 20006; (202) 452-9545; fax: (202) 452-9328.

FLASH FLOOD OR FLOOD WATCH means that flooding is possible within a designated area...be alert!

FLASH FLOOD OR FLOOD WARNING means that flooding is imminent - take necessary precautions at once!

URBAN AND SMALL STREAM ADVISORY is when flooding of small streams, streets and low-lying areas, such as railroad underpasses and urban storm drains, is occurring!