Weather & Wellness (Special Friday Edition): Rising Waters-Understanding Flood Types and Health Impacts

Earlier this month, devastating flooding in Texas resulted in the deaths of 135 people. As of today’s posting (7/18/25), 100 people are still missing. Videos of the flooding revealed entire homes being swept away in the swollen Guadalupe River. Unfortunately, additional flooding events have occurred in New Mexico, New York and Kansas. This week’s special Friday edition of the Weather and Wellness Wednesdays blog will explore the common types of flooding, the impacts of flooding on health, and what we can do to stay aware and prepared.

Flooding Statistics

https://www.weather.gov/hazstat

Flooding is the #2 weather-related killer in the United States, and is second only to extreme heat. There were 145 flood related fatalities in the United States in 2024. The state with the highest number of deaths in 2024 was North Carolina, and many of those deaths can be attributed to the widespread flooding from Hurricane Helene in September 2024.

Types of Flooding

Flooding can occur in any area, can have a rapid onset, or creep up over weeks.  In hurricane prone areas, you will sometimes hear the phrase “If you’ve been through one hurricane...you’ve been through one hurricane”.  That means that the next hurricane you experience may be a different size, a different strength, and may bring different hazards. The same is true for flooding, as it is never a “one-size-fits-all” event.  Listed below are a few common types of flooding.

Flash Floods

Flash floods are defined as flooding that begins within 6 hours of heavy rainfall, or sudden dam/levee failure. Urban areas with poor drainage and areas with steep terrain can be vulnerable to flash floods. The National Weather Services issues flood products ranging from flood watches to flash flood emergencies to the alert the public of flooding dangers.

River (Fluvial) Flooding

This type of flooding occurs when rivers overflow due to prolonged rain or melting snow. In my state of Louisiana, you may be surprised to know that emergency managers keep a close eye on weather in the northern and midwestern states during the winter. Why? Because the Ohio River Basin alone contributes nearly 60% of the water in the Mississippi River, so snowy winters or heavy spring rainfall far away can raise the flood risk here at home in the spring.

In August 2016, a “tropical adjacent” storm system resulted in some areas of southeast Louisiana receiving nearly 30 inches of rain. Rivers in the area became overwhelmed, and backwater flooding from the river tributaries caused record flooding in the area.

Coastal Flooding

Coastal flooding occurs when normally dry, low-lying land is submerged due to seawater intrusion. This type of flooding can result from storm surge from tropical cyclones, extremely high tides such as “king tides”, or sea level rise. According to NOAAs Office of Coastal Management, almost 129 million people or 40% of the US population live in coastal communities, so coastal flooding is a growing concern as the number of residents moving to coastal areas increases.

"King Tide" flooding in Miami Beach, FL: https://www.wlrn.org/environment/2014-09-29/october-king-tide-brings-trove-of-data-for-sea-level-threat-in-miami-beach

Health Impacts of Flooding

Flood Safety

While we can’t prevent flooding from occurring, we can take steps to mitigate loss of life and property. 

1.  Know Your Flood Risk: You can find flood maps at the FEMA Flood Map Service Center webpage or from your city, county/parish, or state emergency management website. Coastal communities can also find hurricane evacuation zone maps on their local emergency management websites. 

2.  Fortify Your Home: Websites such as Flash.org from the Federal Alliance for Safe Homes (FLASH) and https://www.lsuagcenter.com/topics/family_home/home/lahouse from the LaHouse Research and Education Center provide tips and resources for homeowners. 

3.  Stay Alert: Have multiple ways to receive flood warnings. Purchase a NOAA Weather Radio which has battery backup in case of a power outage. Make sure that Wireless Emergency Alerts (WEAs) are enabled on your smartphone. WEAs are location-based messages that are sent to your phone by authorized government authorities. 

4.  Turn Around, Don't Drown! Never drive into a flooded roadway because there is no way to accurately judge the depth of the water. Pay attention to road-signs indicating flood-prone areas, and be cautious when driving in heavy rain, especially at night. 

5.  Practice Safe Mold Clean-up: Wear an N95 or another appropriate respirator while cleaning moldy areas. If you use bleach to clean, use no more than 1 cup of bleach in 1 gallon of water. If you have asthma, COPD, or if you are immune-compromised, you should not stay in a moldy home, or even be present while clean-up is occurring. Visit https://www.cdc.gov/mold-health/about/clean-up.html for additional mold clean-up information. 

6.  Reach Out: If you are feeling anxious or overwhelmed due to flooding or the threat of flooding, reach out to a behavioral health professional for help. One resource is the Disaster Distress Helpline at 1-800-985-5990.

Have you experienced extreme flooding in your area or have flooding resources that you would like to share? Please share in the comments below.