Heat and Flood: Prepare for Climate Change

OCTOBER 4, 2022

The first half of 2022 brought a series of winter storms to Europe, unprecedented flooding in Australia and South Africa, a high number of thunderstorms in the U.S. and Europe, resulting in $35 billion in insured losses. Bottom line: Extreme weather events are increasing in severity and frequency, and understanding the correlation between heat and flooding can help you physically and financially prepare for these exposures.     

How Extreme Heat Relates to Flooding

Flash flooding starts with heat, according to Greg Carbin, the forecast operations branch chief at the National Weather Service’s Weather Prediction Center. “A large swath of the U.S. has experienced mean temperatures within the top 5 warmest summers on record. It has been the warmest (hottest) summer on record in over 100 years,” he said.

Extreme temperatures can lead to draught conditions and very dry environs. Domes of high pressure, or “heat domes,” lock in heat and keep the rain out.

The periphery of the heat dome is where storms are created. The dome’s edges act as conveyor belts for moisture, which result in relentless rain. The rain follows the same path for hours and days on end. Carbin explains: “We already know the potential exists for higher-end rainfall amounts in a warming climate, so it seems that some of these extreme rainfall events, while not necessarily a ‘new normal,’ are certainly more likely to occur than our past records indicate.”

FEMA Flood Maps Are Based on Data From the 1970s

The Department of Homeland Security’s Inspector General revealed that 58% of all FEMA flood maps are considered inaccurate or out of date. The maps fail to take into account climate change. When Kentucky flooded in July 2022, the FEMA maps showed that only 12% of the homes, in three of the hardest hit counties, were at risk of flooding. 

First Street Foundation, a climate research nonprofit organization, created a flood map that included climate change. First Street’s map of Kentucky found that 51% of properties in the same three counties were at risk for flooding. Further, First Street found that almost 6 million properties in the U.S. are at risk of damage during a one-in-100-year flood, even though the properties are not in flood zones.

Mitigating Flood Loss

As heat and rainstorms continue to grow in intensity, consider implementing the following risk management strategies:   

  • Raise your home on stilts or piers. This is an expensive option; however, raising your home above base flood level will substantially protect your home from rising water.
  • Install foundation vents or a sump pump. Foundation vents allow water to flow through your home. This provides an outlet for flood water and relieves pressure on your walls and windows.
    • A sump pump with backup battery is a great option to pump flood water out of the basement. If you lose power, your sump pump will continue working. The average sump pump costs approximately $1,200, with installation between $600 and $1,500. National companies such as Roto-Rooter and Sump Pump Geeks are available to assist.
  • Apply coatings and sealants. Apply coatings and sealants to foundation, walls, windows and doorways to prevent flood water from seeping through cracks of the home.
  • Raise electrical outlets and switches. Raise outlets, switches, sockets and circuit breakers above base flood level to avoid significant electrical damage.
  • Install gate valves on your sewer pipe. Install gate valves to protect your home against sewage backup.
  • Grade your lawn away from the house. Use a heavy soil containing clay or sand to regrade your lawn so water runs off the property into a gutter, versus having water collect around the home.
  • Leave space between mulch and siding. Leaving space between your mulch and home will prevent the siding from rotting. Failing to remediate rot allows water intrusion into the home.
  • Point your downspouts away from your home. Point gutter runoff away from the home to avoid pools around the home and leaks into the basement.

Flood Insurance

The National Flood Insurance Program (NFIP), managed by FEMA, isn’t the only option available for homeowners. Private flood insurance is also now available and may be less expensive than an NFIP policy, and may also offer broader coverage, depending upon the risk. View our NFIP vs. private flood insurance comparison chart for more information.

Third straight week flash flooding is a concern in the same areas of the U.S. Jennifer Gray, CNN Meteorologist, 8/8/22
Flood vs. Monsoon — What’s the difference? WikiDiff
Floods and storms drive global insured catastrophe losses of USD 38 billion in first half of 2022, Swiss Re Institute estimates. Swiss Re Group, 8/2/22
How to Prevent Your House From Flooding. Daniel Caughill, 8/25/21, valuepenguin.com