The Federal Emergency Management Agency, which oversees the national flood insurance program, implemented a new rating system last month that it claims will more accurately reflect the risks of flooding to set annual insurance premiums.
FEMA points out that nearly 40% of the 60,000 flood insurance policyholders in Massachusetts will pay less under the new rating system.
But policyholders in some communities miles away from the coastline, such as Lawrence and Haverhill, could see big increases.
Local elected officials say the rate hikes will hurt businesses and homeowners struggling to recover from the pandemic.
"I understand that insurance rates need to go up, but not by seven times the amount they were a year ago," said state Sen. Barry Finegold, D-Andover, whose district straddles the flood-prone Merrimack River. "I question the timing and the size of these increases. I just don't think it's warranted."
Newburyport Mayor Donna Holaday said she also understands the risks are greater for the federal insurance program with more storms and flooding, but said "the timing of the increases is really poor."
"People and businesses are just trying to come back from the pandemic, so I really don't think this is the right time to be increasing rates," she said.
The federal agency has released details showing how much policyholders in the state could be paying in the first year of the new rating system.
Roughly 39% - or about 22,600 Massachusetts policyholders - would see decreases in their rates in the first year, according to FEMA. About 49% of policyholders - or nearly 28,800 policies - would see increases ranging from zero to $120 a year.
About 6% of the states policyholders would pay between $120 and $240 a year in higher flood insurance rates, the agency said.
Along the Merrimack River, some policyholders would see a decrease in their policies while others would be paying more.
Lawrence would be looking at some of the biggest increases, the FEMA data shows, with more than half of the city's nearly 300 flood insurance policyholders expected to be hit with increases of up to $120 in the first year. Others could see increases up to $240 in the first year, the data shows.
In Haverhill, anywhere from 4% to 41% of the 382 flood insurance policyholders could see increases of up to $120 in the first year, according to FEMA data.
Another 6% to 22% of the city's flood insurance policyholders could see increases of $240 in the first year under FEMA's new rating system.
In Newburyport, about 10% of 535 policyholders will pay up to $120 more a year, while another 6% will pay up to $240, according to federal data.
About 18% of the 104 policyholders in Amesbury will see an increase of up to $120 in the first year, the data shows.
Meanwhile, about 15% of the 435 policyholders in Andover could be looking at rates up to $120.
But policyholders in some other communities on the Merrimack River - including West Newbury - won't see an increase in the first year, according to the data.
FEMA can only increase rates up to 18% annually under federal law, and the agency says it will be spreading out rate increases over several years.
Property owners in high-risk areas with federally backed mortgages are required to carry flood insurance. The National Flood Insurance Program covers about 5 million policyholders, which collectively is more than $1.3 trillion in coverage.
Premiums for flood insurance depend on a number of factors - including the amount of coverage needed - but range from a low of $400 a year to more than $8,000 in high-risk zones, according to figures on the NFIP's website.
A recent report by the First Street Foundation, a New York-based nonprofit that studies the risk of flooding and natural disasters triggered by climate change, predicts Massachusetts could see flooding increase by 35% over the next three decades, which could drive up insurance rates even further.
"As flood events become more expansive, more intense, and more frequent due to a changing climate, the overall number of properties at risk will increase, as well as the resulting financial damage to those properties which were already at risk," the report's author's wrote.
Christian M. Wade covers the Massachusetts Statehouse for North of Boston Media Group's newspapers and websites. Email him at [email protected].