Introduction

Urban flooding can occur quickly and with little warning, especially in communities with large areas of pavement and limited drainage capacity. Even a few inches of water can threaten lives, damage homes and disrupt daily routines. This factsheet provides Oklahoma residents with guidance on what to do before, during and after a flood. By understanding local food risks and taking a few proactive steps, homeowners and families can greatly reduce the impacts of flooding on their property and safety.

What is Urban Flooding?

Urban flooding occurs when heavy rainfall results in stormwater runoff that exceeds the capacity of the area’s natural and built drainage network (i.e., storm sewers, streams, etc.). This causes water to accumulate on streets, in basements and around buildings. In urban areas, flooding can result from both a) prolonged rainfall, which saturates the ground and then causes runoff to accumulate, and b) short, intense storms, where the rainfall intensity exceeds infiltration rates, leading to flash floods. Due to the high prevalence of impervious surfaces, such as roads, rooftops and sidewalks, which prevent water from soaking into the ground, urban areas are particularly vulnerable to flooding. Stormwater runoff can capture debris and pollutants on the surface and transport them into nearby water bodies, thereby contributing to poor and even unsafe water quality. The high density of people, infrastructure and property in urban environments means that even shallow flooding can cause significant damage and serious safety risks.

Why it Matters for Oklahomans

Oklahoma is widely recognized for its extreme weather events, including severe storms, tornadoes, droughts and flash floods, making it one of the most meteorologically dynamic states in the United States. Because many towns and cities were designed using older rainfall records, their storm drainage systems often lack the capacity to handle the stronger and more frequent downpours we experience today.

Urban flooding is not rare in Oklahoma. Major cities such as Tulsa and Oklahoma City have experienced repeated flooding over the past decades, while smaller communities across the state regularly experience localized street and basement fooding. Storms in April and May 2025, which caused widespread road closures and property damage, once again demonstrated how quickly flash flooding can threaten lives and homes. These events show that urban flooding is not limited to rivers or coastal areas; it can happen anywhere heavy rain falls on paved or built-up surfaces. With projected increases in rainfall intensity and continued urban growth, improving flood preparation, home drainage and community stormwater management is more important than ever for protecting Oklahoma families and neighborhoods.

Flood Safety Tips for Urban Residents

How to Prepare Before a Flood (Food Preparedness)

Flood preparedness refers to the proactive measures that urban residents take to minimize the impact of flooding. It is all about being ready in advance so that when a flood occurs, people and communities can respond effectively and reduce potential harm. These actions can be grouped into two categories: those aimed at protecting property and belongings, and those focused on safeguarding individuals’ lives (Figure 1).

A key first step for every urban resident is to develop a preliminary understanding of flood risk for their home, workplace and other frequently visited locations. A practical way to do this is by consulting FEMA’s Flood Insurance Rate Maps (FIRMs) to determine whether a property lies within a designated flood hazard zone. FIRMs typically represent areas with a 1% chance of annual flooding. Those areas have at least a one-in-four chance of flooding during a 30-year mortgage. If your home or business is in a flood hazard zone, purchasing flood insurance can provide peace of mind and serve as an essential step in protecting property and assets. Other proactive measures include installing backflow valves on floor drains, toilets and sinks to prevent sewage backups, and, where applicable, placing a sump pump in the basement to remove water from low-lying areas. Because flooding can also cause power outages, it is advisable to have a backup power source for the sump pump. Additional protective actions include elevating HVAC systems, water heaters and electrical panels above potential flood levels, keeping gutters and drains clear, and considering flood-reducing landscaping such as rain gardens or permeable pavements. When flooding is forecasted or imminent, residents may prepare sandbags, flood gauges or water-inflated barriers, and install removable flood shields for doors and vents.

For personal safety, it is essential to sign up for local emergency alerts and monitor reliable weather sources. Prepare an emergency kit with water, non-perishable food, medications, first-aid supplies, flashlights, batteries and important documents stored in waterproof containers. Develop a Family Emergency Plan that identifies safe evacuation routes, meeting points and communication methods. Be sure to include pets, elderly family members and individuals with special needs in your plan. Finally, learn how to safely shut of electricity, gas and water in case of an emergency.

What to Do During and After a Flood (Flood Response and Recovery)

This refers to the actions taken by urban residents during and immediately after a flood event. We categorize these actions into four groups: Immediate Safety, Communication, Evacuation and Short-Term Recovery, highlighting three key safety tips under each category. A key safety tip is to follow the Turn Around, Don’t Drown (TADD) campaign, first launched by the NOAA National Weather Service. The campaign highlights common misperceptions people have about the power of moving water and their ability to navigate flooded areas. It highlights that just six inches of fast-moving water can knock an adult of their feet, while 12–18 inches of flowing water can sweep away most vehicles, including SUVs and pickups. High water can also hide washed-out roads and bridges. Other important safety measures include moving to the highest level of your home or a safe public shelter. Go to upper floors or rooftops and avoid attics without escape options. Be aware of electrical hazards, as floodwaters in urban areas often conceal downed power lines or live wires. Do not touch electrical equipment if you are wet or standing in water. Only shut of electricity, gas and water if it can be done safely.

During a flood, it is important to follow local emergency instructions promptly and use designated evacuation routes. Stay in touch with family and friends to inform them of your location and use battery-powered or mobile devices to monitor alerts and emergency instructions. When evacuating, keep your emergency supplies and kit close at hand. If it is safe, check on neighbors, especially the elderly, children or people with disabilities.

After the flood, return home only when authorities declare it safe. Do not drink tap water until it has been confirmed safe and avoid wading through floodwater. Document any damage by taking photos for insurance claims, and wear protective clothing, gloves and masks while cleaning debris.

Checklist for Flood Response and Recovery

Immediate Safety

• Avoid walking/driving through floodwaters
• Move to higher ground or upper floors
• Turn of electricity and gas if safe

Evacuation

• Follow designated evacuation routes
• Take an emergency kit and essential supplies
• Assist neighbors if possible

Communication

• Listen to local authorities for evacuation instructions
• Contact family/friends to inform your location
• Keep a charged phone or battery-powered radio

Short-term Recovery

• Avoid floodwaters due to contamination or hazards
• Document damage for insurance claims
• Begin safe cleanup (gloves, masks, disinfectants, etc.)

Summary

In summary, urban flooding is a growing challenge for Oklahoma communities, but many impacts can be reduced through simple, proactive actions. Key takeaways include:

• Know your flood risk using FEMA maps and local information.
• Prepare your home by improving drainage, maintaining gutters, installing sump pumps/backflow valves and elevating utilities where possible.
• Stay informed and ready with emergency alerts, a family plan and essential supplies.
• Prioritize safety during floods, never enter floodwater, use marked evacuation routes and avoid electrical hazards.
• Take cautious steps after the flood, document damage, protect your health and follow guidance from local authorities.

References

• Flood Data Viewers and Geospatial Data
• Flood Safety Awareness Week - TADD