The Southern Nevada Health District is providing information to deal with the health implications
regarding safety and property during and after flash floods.
Residents who use private wells for their drinking water should be safe unless a large amount
of erosion at the well head occurred, or the well head was under water for any period of time. If
a change in the color or taste of the water is noted, or if the well head was covered by water, it
should be boiled vigorously for two to five minutes to use for drinking and cooking. Additionally, the well should be sanitized.
Most wells in the valley are approximately 400 feet deep and are 8-5/8 inches diameter. Wells
may be sanitized by contracting a water well professional or by pouring one gallon of
household bleach into the well and turning the pump on and off two or three times to mix the
bleach and water. Then faucets in the house should be turned on until a bleach odor is
detected. This should be done for each faucet in the house. Once this step is completed water
must be left off for at least five hours. At the end of this time period the system should be
The system can be flushed by turning on the lawn irrigation system until no bleach odor is
detected. After this time faucets in the house can be flushed. Flushing in this manner will not
damage a septic system.
To test for bacteria in the water contact Quest Diagnostics at (702) 733-3790. Quest will provide
bottles for testing, instruction on sample collection and information on associated costs.
If the flood waters reach into the garage or home, or affect any food establishments, food safety
can also be an issue. The Centers for Disease Control and Prevention (CDC) provides excellent
guidelines as to what food is safe to keep and what food should be discarded.
Do not eat any food that may have come into contact with the flood water unless it is in a
hermetically sealed container that can be disinfected using a bleach solution of one cup of
bleach in 5 gallons of water.
Anything with a twist off or crimped lid should be discarded. Do not keep any food or formula
for use by infants regardless of packaging. Infants are at a much higher risk than the general
public of contracting a disease carried by flood water.
If the flooding results in a power outage, protect frozen or refrigerated food by keeping the
doors to the refrigerator/freezer closed at all times, or seek an alternate location with power to store the
Do not keep food that has been at room temperature for more than two hours. The best
rule of thumb with refrigerated foods is "When in doubt, throw it out."
Restaurants and other food establishments directly affected by flooding, including power
loss, must not operate during the crisis and must follow all guidelines outlined by the
Southern Nevada Health District before reopening.
Clean up and Personal Hygiene
Do not allow your children to play in the flood waters or with any of the rocks, mud, or debris generated by the flooding. The water may be full of filth, including raw sewage from failed lift stations, sewers or septic systems, which can cause serious illness or injury to children.
Anyone coming into contact with the water or its contents, should apply the following good personal hygiene practices:
Wash hands with soap and warm, clean water for at least 20 seconds before preparing or eating food, after toilet use, after participating in any flood cleanup activities, and after handling
articles contaminated with flood water or sewage.
Clean up should be performed as soon as possible:
Walls, hard-surfaced floors, and many other
household surfaces should be cleaned with soap and water and disinfected with a solution of 1
cup bleach to 5 gallons of water.
Be particularly careful to thoroughly disinfect surfaces that
may come in contact with food, such as counter tops, pantry shelves, refrigerators, etc.
Areas where small children play should also be carefully cleaned.
Wash all linens and clothing
in hot water, or dry clean them.
For items that cannot be washed or dry cleaned, such as
mattresses and upholstered furniture, air dry them in the sun and then spray them thoroughly
with a disinfectant.
Steam clean all carpeting.
If there has been a backflow of sewage into the
house, wear rubber boots and waterproof gloves during cleanup.
Remove and discard contaminated household materials that cannot be disinfected, such as wallcoverings, cloth, rugs, and drywall.
Other hazards must also be considered, especially during flash flooding.
Swiftly Flowing Water
If you enter swiftly flowing water, you risk drowning – regardless of your ability to swim.
Swiftly moving shallow water can be deadly, and even shallow standing water can be
dangerous for small children.
Cars or other vehicles do not provide adequate protection from
flood waters. Cars can be swept away or may break down in moving water.
Wild animals may be forced from their natural habitats by flooding, and many domestic
animals are also without homes after the flood. Take care to avoid these animals, because some
may carry rabies.
Remember, most animals are disoriented and displaced, too. Do not corner an
animal. If an animal must be removed, contact your local animal control authorities.
The Southern Nevada Health District can provide information about the types of wild animals that carry rabies in your area.
Rodents may be a problem during and after a flood. Take care to secure all food supplies, and
remove any animal carcasses in the vicinity by contacting your local animal control authorities.
If you are bitten by any animal, seek immediate medical attention. If you are bitten by a snake,
first try to accurately identify the type of snake so that, if poisonous, the correct anti-venom may
Use extreme caution when returning to your area after a flood. Be aware of potential chemical
hazards you may encounter during flood recovery. Flood waters may have buried or moved
hazardous chemical containers of solvents or other industrial chemicals from their normal
If any propane tanks (whether 20 pound tanks from a gas grill or household propane tanks) are
discovered, do not attempt to move them yourself. These represent a very real danger of fire or
explosion, and if any are found, police or fire departments or your State Fire Marshal's office
should be contacted immediately.
Car batteries, even those in flood water, may still contain an electrical charge and should be
removed with extreme caution by using insulated gloves. Avoid coming in contact with any
acid that may have spilled from a damaged car battery.
Flash floods can cause enormous damage in a short amount of time, yet recovery may be a long
process. Take care of your family's and your personal health and safety during this stressful
Please contact the Southern Nevada Health District with any specific questions not answered
here. Many excellent links about flood safety are available on our Related Links webpage.