FLOODING CONCERNS
Barriers to protect city studied
Sea walls, deployable flood barriers and landbased dams around Boston are all being weighed as possible guardians against global warming in two studies on rising tides due out in March.
“The reports will increase the political will to deal with climate change because the public now knows a taste of the threats of coastal flooding,” said University of Massachusetts Boston professor Paul Kirshen, who is working on the reports. “This amount of flooding will only increase.”
Thursday’s nor’easter set an all-time record for high tide in the city when waters rose 15.16 feet (4.88 feet above the astronomical high tide), breaking the previous record of 15.1 feet recorded during the Blizzard of 1978.
The epic spillover hit just before 1 p.m. and sent city first-responders into downtown streets on rubber rafts to rescue motorists trapped in floodwaters.
Something needs to be done soon, said Legal Sea Foods President and CEO Roger Berkowitz. The basement of Legal’s Long Wharf location flooded in the storm, closing the restaurant for the day.
“The sooner we embrace the notion that it will happen again in the relatively near future, the sooner we’ll be called to take action,” Berkowitz said. “Some kind of mitigation needs to take place. This storm was a wake-up call, we need to start paying attention now, not later.”
Mayor Martin J. Walsh blamed climate change — as he’s warned about in the past — and city officials have been examining potential solutions while waiting on two reports from UMass Boston’s Sustainable Solutions Lab on costs and logistics of sea walls.
“We’re looking at landbased solutions as well as partnering with UMass on
analyzing a sea wall so we can understand all the options on the table and chart a path that will be most efficient and most impactful,” said city Chief of Environment Austin Blackmon. “Certainly we could see a combination of district-level and land-based solutions but that doesn’t rule out doing something harborside as well.”
A 2017 study commissioned by the city listed some land-based solutions for high-flood areas that would include a flood wall in the East Boston Greenway. But barriers come with different side effects, Blackmon said.
Land-based walls and earthen barriers could impede foot traffic along the harbor, and sea walls could change tidal currents and make it harder for smaller boats to enter and exit.
However, the price difference between a sea wall and land-based measures is vast.
UMass Boston professor David Levy, who has led the cost study, said a large sea wall from Winthrop to Hull could top $20 billion, while the East Boston plans would cost between $50 million and $80 million.
And a sea wall comes with other hurdles, Kirshen said. While land-based improvements could be made with minimal federal involvement, making a significant change to Boston Harbor would be a “regulatory nightmare” involving the Army Corps of Engineers, the EPA and even the FAA.
Kirshen stressed the debate will be over cost and a system that is “more adaptive” to flooding trends.
But, the experts agree, flooding is now all too real in the city.
“People aren’t going to be investing here and coming to live here if they see these risks,” Levy said. “In a broader sense we need to have a good resilience plan to make these investments to keep the city competitive as well as safe.”