Flash flood warning: Texas flash flood preparedness

May 11, 2023

Learn how to prepare for and stay safe during the next Texas flash flood warning

A sign near water crossing warning of flash floods

Texas is known for its crazy, often unpredictable weather which brings severe thunderstorms, hail, and tornadoes. But storms also bring rain - sometimes way too much rain - which can often cause significant floods and flash floods across the state. 

In fact, Texas floods are so well known that they have even been immortalized in the classic blues tune by the late, great Stevie Ray Vaughan, "Texas Flood." But while such events make for great songs, they can be and often are incredibly destructive and dangerous. Every year, flash flooding in Texas causes significant damage to property, infrastructure, and unfortunately, loss of life.

So why are flash floods so common and dangerous here in Texas? Why do they call it Flash Flood Alley? More importantly, what should you do if you find yourself in the middle of a flash flood warning? Today, we'll take a look at the causes of flash flooding, the dangers it poses, and how to prepare and stay safe during a flash flood - read on! 

Introduction to Texas flash floods

It's well known that extreme weather events, like severe thunderstorms and tornadoes, are dangerous; we hear about tornado outbreaks and see the aftermath and loss of life they can be responsible for. But while that is certainly true, flash floods, and floods more generally, are some of the most dangerous and deadly weather events that Texans face.

In fact, according to the National Weather Service, flash flooding is the leading cause of weather-related deaths in Texas (even over tornadoes). In part, this is because flash floods can occur suddenly and without warning, turning streets into rivers and sweeping away anything in their path. 

In the past, major flash floods have caused significant destruction. For example, historic floods on Memorial Day Weekend in both 1981 and 2015 were both responsible for a number of deaths, missing persons, and tens of millions of dollars in damage in cities like San Marcos, Austin, Houston, and the surrounding communities. 

This is why it's crucial for residents to understand the risks and be prepared for the possibility of a flash flood. Understanding the nature of flash floods and how to stay safe during these events can help prevent such tragedies from occurring in the future.

What is a flash flood?

A flash flood is a rapid and extreme flow of high water into a normally dry area, or a rapid water level rise in a stream or creek above a predetermined flood level. Flash floods can occur within minutes or hours of excessive rainfall, a dam or levee failure, or a sudden release of water held by an obstruction, such as a log jam, debris flow, or ice jam. They are characterized by their sudden onset, short duration, and often destructive power.

Flash floods can be particularly dangerous because they can happen with little to no warning, catching people off guard and leaving them with little time to react. Additionally, the rapid rise in water levels can create strong currents, making it difficult or even impossible for people and vehicles to escape the floodwaters. 

Causes of flash flooding in Texas

Understanding the causes of flash flooding can help residents identify potential risks and take steps to prepare for these dangerous events. There are several factors that contribute to flash flooding in Texas, such as:
  1. Heavy rainfall: Texas is no stranger to torrential downpours, particularly during the spring and fall months when thunderstorms, tropical storms, and hurricanes are most common. When heavy rainfall occurs in a short period of time, the ground can become saturated quickly, causing water to flow rapidly into streams, creeks, and low-lying areas.
  2. Slow-moving storms: When a thunderstorm moves slowly or stalls over an area, it can dump large amounts of rain in a concentrated location, leading to flash flooding.
  3. Urbanization: As cities and towns continue to expand, more land is covered in impervious surfaces, such as roads, parking lots, and buildings. This increases runoff during rainfall events and can exacerbate flash flooding.
  4. Dam or levee failures: If a dam or levee is compromised or fails, the sudden release of water can cause catastrophic flash flooding downstream.
  5. Burn scars: Areas that have recently experienced wildfires may be more susceptible to flash flooding, as the scorched soil is less able to absorb water, leading to rapid runoff.
As an additional note regarding hurricanes and tropical storms: It's important to understand that these massive storms systems can and often do bring immense volumes of rain far beyond the immediate coastal area. Although the main damaging winds and storm surge are usually isolated to the coast, it is not uncommon for a hurricane or tropical storm to dump flash-flood levels of rain hundreds of miles inland. 

Where is Flash Flood Alley in Texas?

Texas has a particularly high risk of flash flooding due to a region known as Flash Flood Alley. This area stretches from the Rio Grande Valley in the south, up through Central Texas, and into the Dallas-Fort Worth Metroplex in the north. Flash Flood Alley is particularly prone to flash flooding due to its unique combination of geography, climate, and urban development.

The region's geography includes steep terrain and shallow often clay-rich soils, which can quickly become saturated during heavy rainfall, causing runoff to flow rapidly into streams and creeks. The climate in Texas is characterized by periods of drought followed by intense rainfall, which further exacerbates the risk of flash flooding. Finally, urban development in the area has increased the amount of impervious ground, such as roads and buildings, which can contribute to faster runoff and increased flash flood risk.

Like all weather events, flash floods are more or less seasonal. As you might guess, flash flood season aligns closely with severe storm and hurricane season from April through September. That said, flash floods as a result of intense, heavy rain can occur outside of that range. For example, the Halloween Flood of 2013 in Central Texas occurred in late October. 

If you don't live in Flash Flood Alley proper, that does NOT mean your area cannot be impacted by flash flooding. Any area with favorable geographic features and/or urban development can flood if rainfall is sufficient. 

The dangers of flash floods

The strength and shear power of rushing water cannot be overstated. Although many often underestimate it, flash floods pose numerous dangers to both people and property. Some of the most significant hazards associated with flash floods include:
  1. Drowning: According to the Centers for Disease Control and Prevention (CDC), over half of all flood-related drownings occur when a vehicle is driven into floodwaters. Additionally, people can be swept away by fast-moving water or become trapped in submerged vehicles or structures.
  2. Structural damage: The force of rushing water can cause significant damage to buildings, roads, and bridges, posing risks to both people and property.
  3. Contaminated water: Floodwaters often contain dangerous contaminants, such as sewage, chemicals, and debris. This can pose health risks if a person comes into contact with the water or if it enters homes and businesses.
  4. Electrocution: Floodwaters can cause electrical hazards if they come into contact with power lines or electrical systems. This can result in electrocution or fires.
  5. Mold and mildew: After floodwaters recede, damp conditions can encourage the growth of mold and mildew, posing potential health risks and causing damage to structures.
Being aware of these dangers can help you take the necessary precautions to protect yourself and your property during a flash flood event.

Flash flood warnings and watches

Similar to severe thunderstorm and tornado watches and warnings, the National Weather Service (NWS) issues flash flood watches and warnings to alert the public to potential or imminent flash flooding. It is important to understand the difference between these two alerts and know how to react to each.

Flash flood watch. A flash flood watch means that conditions are favorable for flash flooding in the watch area and usually covers a more broad region. This is not a guarantee that flash flooding will occur, but it is a signal that you should be prepared for the possibility. If a flash flood watch is issued for your area, closely monitor weather conditions, and be prepared to take action if a warning is issued.

Flash flood warning. A flash flood warning means that flash flooding is either occurring or imminent in the warning area. Flash flood warnings typically cover a much smaller area than a watch and are associated with a thunderstorm system with intense rainfall. If you receive a flash flood warning, take immediate action to protect your family and your property. Move to higher ground if possible, and avoid driving through flooded areas.

It's important to stay informed about weather conditions in your area, particularly during times of heavy rainfall. Check local weather forecasts regularly and sign up for emergency alerts to stay up to date on any flash flood watches or warnings.

Texas flash flood preparedness tips

Being prepared for a flash flood can make all the difference in staying safe during an emergency. When you have minutes to act, every second counts. Here are some tips to help you prepare for a flash flood:
  1. Create an emergency plan: Develop a plan for yourself and your family in case of a flash flood. Identify safe routes to higher ground, and make sure everyone in your household knows the plan.
  2. Build an emergency kit: Put together an emergency kit that includes essential items like food, water, and first aid supplies. Keep the kit in a waterproof container and easily accessible in case you need to evacuate quickly.
  3. Stay informed: Stay up-to-date on local weather conditions and emergency alerts. Know the difference between a flash flood watch and warning and be prepared to take action if necessary.
  4. Protect your property: Take steps to protect your property from flood damage, especially if you live in a flood-prone area. Install flood-resistant barriers, elevate appliances and electrical systems, and speak to your insurance agent about purchasing flood insurance if you don't already have it. 
By taking these steps to prepare for a flash flood, you can minimize the risks and stay safe during an emergency.

How to stay safe during a flash flood

If a flash flood warning is issued in your area, take immediate action to protect yourself and your property. Here are some tips to help you stay safe during a flash flood:
  1. Move to higher ground. If possible, move to higher ground immediately. Avoid walking or driving through floodwaters, as the current can be strong enough to sweep you away.
  2. Stay informed. Although weather information is important in the days and hours leading up to a flash flood, it's equally important during such an emergency. Having a way to receive updated information about the developing situation is key to safe decision making. 
  3. Avoid electrical hazards. Stay away from electrical lines and equipment that may have come into contact with floodwaters. Do not use electrical appliances that have been submerged in water until they have been inspected and deemed safe by a professional.
  4. Be cautious when returning home. After a flood, be cautious when returning to your home or business. Look for signs of structural damage, and avoid entering if you suspect the building may be unstable.
  5. Watch for potential hazards. Floodwaters can create hidden hazards, such as downed power lines or submerged objects. Be aware of your surroundings, and watch for potential hazards as you move through flooded areas.
  6. Turn around, don't drown. Flooded streets, roadways, and bridges can be deceptively deep, and moving water is far more powerful than many people realize. Just six inches of water can begin to move a car and 12 inches will float most vehicles. If you see warning signs or water moving across a road, don't risk it - turn around, don't drown.
If you find it is too late to evacuate, or if you are told not to evacuate and shelter in place, seek shelter on the highest story of your home or your roof if possible and call 911. Do not climb into an attic or room without a viable exit. As the flood waters rise, it is possible to become trapped inside. 

Insurance and flash flooding in Texas

As we've discussed here, flash floods can be devastating to both life and property. Although flash flood awareness and preparedness are essential for protecting you and your family from harm, insurance can help when it comes to property loss.

Auto insurance. If your vehicle is damaged in a flash flood, comprehensive auto insurance can help you repair the damage or replace the vehicle if needed. Keep in mind that the minimum liability coverage required by Texas will not provide coverage for flood damage, so make sure to review your policy. 

Homeowners insurance. Your standard homeowners insurance policies in Texas do not cover flooding, but flood insurance is available through FEMA and the National Flood Insurance Program (NFIP). Homes within a designated flood zone are required to carry flood insurance by mortgage lenders, so make sure to speak to your insurance agent to ensure you have the coverage you need. 

Lastly, flood insurance has a waiting period before going into effect, which is usually 30 days. That's why it's best to speak to your agent sooner rather than when you see storms in the forecast. 

Conclusion and additional resources

Flash floods are a serious and potentially life-threatening weather event in Texas. Being prepared and knowing what to do during a flash flood can help keep you and your loved ones safe. Remember to stay informed, create an emergency plan, build an emergency kit, and take steps to protect your property from flood damage.

For more information on flash flood preparedness, visit the Texas Department of Public Safety's website or the National Weather Service's flash flood safety page. By taking the necessary precautions, you can stay safe during the next flash flood warning in Texas.

A car submerged after a flash flood

For more information about Germania's insurance products, request a free quote online or reach out to your local agent today!

by Geoff Ullrich

About the Author

Geoff Ullrich is a writer and Content Marketing Strategist at Germania Insurance.

What do you want to read more about? For suggestions, questions, or content-related inquiries, contact us at content@germaniainsurance.com!

Roadside Assistance

We’re here for you, 24/7/365.


File a Claim

File a claim online, by phone or by contacting your agent.


Find An Agent

Find a Repair Shop