Here Are The Arizona Cities With The Greatest Risk Of Flooding

PHOENIX, AZ — A new report from the First Street Foundation provides a national analysis of flood risk in states and cities across the United States, including in Arizona.

The nonprofit, dedicated to the research and development of flood prevention, released a model that allows users to assess flood risk in the past, present and future at the individual property level by location. The risk assessment takes into account sea-level rise, rainfall and flooding along smaller bodies of water.

The new in-depth report estimates that 14.6 million properties across the United States are at substantial risk of flooding, which is a staggering 5.9 million more properties than the Federal Emergency Management Agency (FEMA) shows on federal government flood maps.

First Street uses three risk description levels to classify the chances of flooding in an area:

• Almost certain risk: 20 percent annual probability
• Substantial risk: 1 percent annual probability
• Any risk: 0.2 percent annual probability

Here's the risk of flooding in Arizona, according to the First Street Foundation.

• Total properties at substantial risk in 2020: 118,700
• Total properties at substantial risk in 2050: 120,600
• Difference in the number of properties currently at substantial risk compared to FEMA maps: -10,800

When looking at all levels of flooding risk in our state, the data shows 367,600 properties at any type of risk over the next 30 years. Of these, 24,700 are categorized as facing almost certain risk.

Here are the cities and towns in Arizona that have the highest numbers of properties at risk of flooding.

1. Phoenix: 62,351 properties in 2020
2. Glendale: 25,429 properties in 2020
3. Scottsdale: 17,781 properties in 2020
4. Peoria: 7,850 properties in 2020
5. Maricopa: 7,479 properties in 2020

Tucson sits at seventh on the list with 5,404 properties at risk in 2020.

You can use the nonprofit’s new Flood Factor tool to check the flood risk of your exact address.

While the data from First Street shows that flood risk in the nation is much higher than FEMA’s estimates — despite FEMA actually having a higher estimate in Arizona — the government agency welcomes the new data from the nonprofit.

“We know there is no perfect science to predict flooding,” a FEMA spokesperson told the New York Times. “The Flood Factor product may help property owners with the critical decisions they must make and purchase necessary insurance.”

Additionally, FEMA’s maps don’t take into consideration flooding caused by intense rainfall, which First Street’s model does.

The First Street Foundation’s new report was made in collaboration with more than 80 scientists, technologists and experts, as well as in partnership with researchers from Columbia University, George Mason University, Massachusetts Institute of Technology and others.

You can read more about the methodology of the nonprofit’s report on its website.