(Courtesy of Ellen Douglas and the Boston Harbor Association)
During a presentation on Columbia Point on Monday night, Dr. Ellen Douglas encouraged her audience of residents and city officials to cast a weary eye toward the harbor and imagine a worst-case scenario.
Douglas, a professor of hydrology at UMass Boston, had mapped out what Boston Harbor would look like if a five-foot storm surge smacked the coast during an astronomical high tide, at a time when the sea level was 2.5 feet higher than now.
Fort Point would be entirely flooded. Along the Neponset River, water would swell onto the shore, submerging areas well over six feet. And the Harbor Point Club House, where the presentation took place, would also be swamped.
While waterfront areas like South Boston, Dorchester, East Boston, and Charlestown would be immediately affected, a severe storm would also overwhelm the Charles River Dam, bringing flood waters to the Back Bay, the South End, and parts of Cambridge.
Douglas has been presenting this data at community meetings for the past month, visiting other susceptible waterfront areas like East Boston, Fort Point, and at the New England Aquarium. She's shown concerned residents that reducing carbon emissions could significantly temper sea level rise, but that it's also an inevitable reality of living near the water.
Vivien Li, of the Boston Harbor Association, the group that has organized Douglas' lectures around the city, said that the purpose of the talks was to inform the communities most affected by the sea level rise.
"We wanted to share this, to protect our property, ourselves and our children," she said. "We wanted to make the community more aware now, and give us enough time to plan."
If carbon dioxide emissions continue at current levels, Douglas said the sea level could rise by 2.5 feet increase in sea level within the next 50 years and a six-foot increase by the end of the century. If we substantially reduce carbon dioxide emissions, the 2.5-foot sea level rise could hit at the end of the century.
Douglas showed photos of flooding that has already occurred near the New England Aquarium, and quoted a New York Times article in which scientists measuring sea level rise in Greenland called the developments of the last five years "alarming."
"Scientists are not alarmist by any means,'' Douglas told attendees. "They're actually trained to be the opposite of alarmist."
Douglas and her UMass Boston colleague Chris Watson numerated several ways to mitigate and prepare for the changes.
They recommended that residents practice sustainability, like recycling, home weatherization, and energy efficiency. They recommended new developments be prepared for flooding, citing the new Spaulding Rehab facility in the Charlestown Navy Yard, which has elevated the building and opted not to keep its mechanical utilities in the basement, which could be prone to flooding. They also recommended a "safe guarding" approach that would keep flood-prone land undeveloped.
Some residents expressed dismay that the new convention center in South Boston was among the properties that Douglas named as at-risk for major flooding. The site of the recently approved Seaport Square project, as well as the area of Fort Point that the mayor has dubbed an "Innovation District," are also at risk for six-foot swells.
After the meeting, Carl Spector, director of the city's Air Pollution Control Commission, said that the Boston Redevelopment Authority had begun to take sea level rise into account for waterfront developments.
"Any project near the coast that goes before the BRA is being asked to consider sea level rise," he said. He added that Seaport Square's plan "is more general at this point, because we're still at the beginning of the conversation," but that "their permit includes an agreement to develop adaptation measures" for possible flooding.
Residents also wanted to know about the level of flooding in particular neighborhoods, especially the Columbia Point area.
"These maps are really only designed to look at the whole area," Watson said. "What we can't show with these maps, because of the limitations of the data, is exactly whose house is going to be flooded, and exactly what streets are going to be flooded."
Watson added that getting more precise maps would involve hiring engineers and surveyors. Doing that for the entire harbor is an expensive process. He suggested that neighborhoods pool resources to have that work done.
Spector added that climate change was being studied at both the city and state level. He also pointed out that Boston Water and Sewer Commission is in the midst of a planning process for replacing its 100-year-old storm sewers. He also said that the city has updated its emergency management program.
"We know floods are going to be happening more often, even before the sea level gets really high," he said. "That is comprehensive: floods, fires, terrorists, everything. But climate change is being integrated into that, so the city is making sure that it has the capability and the resources necessary to respond to more frequent emergencies."
For more information on sea level rise and its effect on the harbor, go to tbha.org