Flood Plain – Mitigation
Threats of rising flood levels are slowly changing the face of many Massachusetts communities.
Existing waterfront properties are moving up or back to escape potential flooding. Other structures are going away entirely, leaving a buffer area to blunt future floods. Municipalities are updating construction codes to require heating and cooling systems be moved from vulnerable basements to higher floors.
These changes are being made for reasons beyond mitigating storm damage. By securing structures or moving them up and out, property owners can literally rise above new flood plain designations, reducing the cost of their insurance.
Anne Herbst, Hull’s conservation manager, said more people are considering “freeboarding,” the process of elevating homes above predicted flood levels. Hull’s planning board now offers a one-time $500 credit against permitting costs to those who build two feet higher than required elevations.
Since the freeboarding incentive program began four years ago, 85 percent of the 30 projects seeking building permits have opted to raise foundation levels.
“I think [residents are] increasingly aware. If the flood insurance rates start to rise dramatically, that would also drive their awareness,” she said.
Marshfield is considering a variance that would make it easier for homeowners to raise their houses from the bottom while maintaining their views.
Town planner Paul Halkiotis plans to propose zoning by-law changes that would allow homes to exceed the town’s 35-foot height limit if it done to raise the bottom of the structure above projected flood plain levels.
““You don’t have to get as tangled up in as much red tape,” Halkiotis said.
Jack Clancy of Clancy Construction in Marshfield said he has received more calls this year from people looking to elevate their homes after learning new flood plain maps being developed by FEMA will place them in higher-cost insurance zones.
“It certainly caused a lot of confusion,” Clancy said. “[It is] leaving people fearful. They’re saying to themselves ‘what’s going to happen?’”
Raising a home is no small task. Surveyors and engineers must determine the necessary elevation for the first floor; structural engineers must decide how best to elevate the house. Homeowners then apply to the town’s conservation commission for approval.
Clancy said he could not estimate the cost of elevating a home because it involved too many factors ranging from the foundation of the house to its elevation.
But not all homeowners have to elevate their homes.
“It may be as simple as installing flood vents,” under the home which allows flood waters to flow through, Clancy said.
In Boston, builders are now required to outline how they’ll prepare for sea level rise before they’re granted a building permit. The Boston Redevelopment Authority voted on these new building permit requirements in November.
“We need to understand what’s vulnerable and what would be damaged and what is our vision for what we are going to do about it,” said Julie Wormser, executive director for the Boston Harbor Association.
To prepare for sea level rise, Boston’s Marriott Long Wharf hotel has elevated its critical infrastructure up to the second floor at a cost about $20 per square foot, Wormser said.
Despite the efforts, officials say more needs to be done.
Curt Spalding, the U.S. Environmental Protection Agency administrator for the New England region, said only 5 percent of New England communities have addressed flood risks.
He said in addition to raising or moving homes, towns might consider buying up properties to create open space as a buffer to flooding.
That happened in 2003 when 22 homeowners and tenants along the Spicket River in Lawrence were permanently relocated out of the floodplain at a cost of $1.4 million, paid for primarily with FEMA mitigation grants.
The neighborhood was converted to a field. When the river flooded the field during a storm in 2006, two dozen fewer families were impacted in comparison to past flooding.
Local and state planners could take a cue from Louisiana, which began organizing efforts at a state level after Hurricane Katrina. The state established the Coastal Protection and Restoration Authority, a 20-person board that assesses coastal projects and mitigation strategies.
The board decides what projects are most urgent, Garrett Graves, chair of the board, said in November at a Boston meeting of the National Institute for Coastal and Harbor Infrastructure.
The board, comprised of a variety of state agencies, meets monthly and has pooled $17 billion to fund projects from almost 40 different providers. The board oversees joint efforts to map coastal regions to measure flooding risks, and then, find the best way to tackle these risks.
“You have got to have a venue where folks can all collaborate and you can have accountability,” Graves said.