US flood maps are outdated because the impact of climate change is so overwhelming, disaster expert says

• US flood maps are outdated — and it's all because of excess rainfall caused by climate change.
• That's according to FEMA, which says more American homes and businesses could be at risk.

US flood maps used by Federal Emergency Management Agency have become outdated, according to FEMA director Deanne Criswell — and it's all because of excessive rainfall caused by climate change.

US flood maps tend to focus on riverine and coastal flooding, Criswell said on CNN's "State of the Union" show Sunday, as reported by Bloomberg.

"The part that's really difficult right now is the fact that our flood maps don't take into account excessive rain that comes in," Criswell said. "And we are seeing these record rainfalls that are happening."

Record rainfall that is plaguing parts of the US — like the flooding in Jackson, Mississippi, in recent weeks — can oftentimes be missing from these flood maps and significantly understates the risk of flooding to American homes and businesses.

The crisis in Jackson was so acute that around 150,000 people did not have access to safe drinking water, and the city temporarily ran out of bottled water for residents, according to CNN.

The New York Times reported Sunday that climate change — which has also prompted wildfires and hurricanes over the years — is also contributing to a water catastrophe that could be felt in communities beyond Jackson.

"FEMA's maps right now are really focused on riverine flooding and coastal flooding and we work with local jurisdictions to update the maps," Criswell said. "We have to start thinking about what the threats are going to be in the future as a result of climate change."

Rainfall in three US states broke century-old records

Criswell stressed that FEMA would work with local communities "to help them better identify what their needs are and help them create better predictive models."

"We have to start thinking about what the threats are going to be in the future as a result of climate change, so they can put the mitigation measures in place," she said.

Rainfall in Missouri, Kentucky, and Illinois last month shattered records that lasted 100 years, according to The Guardian.