News Photo by Steve Schulwitz Prentiss Street is blocked off on Monday as water from Thunder Bay floods over the roadway. As Great Lakes water levels rise and extreme rainstorms occur, the threat of flooding in Northeast Michigan rises. A new report says flood maps filed with the federal government significantly understate the number of properties at risk of flooding between now and 2050.

ALPENA — A recent study claims flood maps on file with the federal government are obsolete and gravely understate the number of homes at risk of flooding.

The peer-reviewed study by the nonprofit First Street Foundation identified 7% of Presque Isle County properties at risk of flooding between now and 2050, compared to the Federal Emergency Management Agency’s maps showing 4% of properties are at risk.

That means First Street identified 1,704 more at-risk properties than FEMA.

In Montmorency County, FEMA says 4% of properties are at risk of flooding, while First Street says 6% are at risk, which equates to 1,220 additional at-risk properties.

In Alcona County, the numbers are reversed, as First Street says FEMA identified 472 properties at risk of flooding that are not at risk.

Alpena County wasn’t included in First Street’s data. It wasn’t immediately clear why. Local emergency management officials couldn’t be reached for comment on this story.

First Street’s team utilized information from several existing models on sea level rise, river flooding, and simulations of extreme weather events, according to a story in USA Today. FEMA’s maps look mostly at historical data to predict future flood risk.

First Street created an online tool allowing people to review whether their home or a home they hope to buy is at risk currently or will be in the future, helping them determine whether they need flood insurance.

According USA Today, First Street found about 14.6 million homes and other structures across the country at risk of flooding. FEMA lists 8.7 million properties in the floodplain, a 40% undercount compared with what First Street found.

Steve Schulwitz can be reached at 989-358-5689 at sschulwitz@thealpenanews.com. Follow him on Twitter @ss_alpenanews.com.