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Thursday, January 5, 2012

Potential sea-level rise impacts in East Boston

Activists warn of potential sea-level rise impacts in East Boston

by Jeremy C. Fox,,  January 4, 2012
(The Boston Harbor Association)
A map developed by Ellen M. Douglas and Chris Watson of UMass Boston and Paul H. Kirshen of the Battelle Institute for The Boston Harbor Association shows possible effects of sea-level rise on East Boston and surrounding communities.
Some scientists believe climate change could cause Boston Harbor to overflow its banks and return parts of the city to the marshland it once was, but local activists hope an educated public can reduce the impact of rising sea levels and help protect vital resources and communities.

The issue is particularly pressing in East Boston now, given the proposals outlined by Mayor Thomas M. Menino last month that would encourage development along the neighborhood’s waterfront, an area that could one day be fully submerged beneath Boston Harbor. In Menino’s annual speech before the Boston Chamber of Commerce on Dec. 6, he cited five waterfront projects that stalled due to financing problems or other difficulties but that he hopes can be jumpstarted by municipal investments in the waterfront.

In a December phone interview, community activist Neenah Estrella-Luna cautioned that any new waterfront development has to be done with foresight. “One of my biggest concerns is how are they taking into account climate change in all of these waterfront development projects,” she said.
Estrella-Luna, who teaches public policy at local universities, is part of a group of educators, architects, and housing advocates who have come together throughCommon Boston, a volunteer committee of the Boston Society of Architects that works to address urban environmental issues.
She fears that proposed developments along the waterfront could ultimately become damaged by rising waters, making them undesirable as residences. Rather than market-rate units, they could be transformed into low-income housing, similar to what happened decades earlier at the Shore Plaza East apartments on Border Street, she said.

“I hate to say that, because [Shore Plaza East] has good people in it, but it's badly maintained,” she said. And because the complex was built just above the current sea level, she said, it already experiences flooding of its lower parking deck during heavy rains.

In an earlier public presentation on the risks of sea-level rise, Estrella-Luna explained how melting polar ice and warmer ocean waters caused by global climate change could cause the harbor to rise by several feet, though the number varies based on the predictive model used. “They range from ‘let’s hope’ to ‘oh, my God,’” said Estrella-Luna, who said the projections seem to increase each year, with current estimates predicting a minimum of a 2.5-foot increase within the next 50–75 years. The worst-case scenario would be a 5-foot rise.

As average sea levels rise, so do levels during storms, daily high tides, and bi-monthly high tides caused by lunar cycles — known locally as “wicked high tides.” The daily rise in high tides could mean increased flooding of basements and sewers, as well as beaches, wetlands, and low-lying roads near the shore. Combine that with the bi-monthly increase or with the storm surge caused by harsh weather, and the effect is amplified. Already some areas around Boston Harbor flood during especially high tides.

“With that minimum two-and-a-half-foot sea-level rise, our low tides come up higher, and our high tide basically gets very close to where wicked high tide is,” Estrella-Luna said. “This is what we can expect to happen daily, given how things are structured now. And then of course, wicked high tide, with sea-level rise, it’s definitely an 'uh-oh.' ”  Using a model she described as conservative and simple, in that it doesn’t take into account the absorbency levels of different types of soil, Estrella-Luna showed potential outcomes of raised water levels, though she warned that the maps could not depict the exact state of any specific street or district.

The images painted a disturbing scenario for neighborhood residents. With 2.5 feet of sea-level rise, only a few spots on the waterfront would be affected under normal conditions, but a map showing the city with a 5-foot increase depicts large areas of flooding across the South Boston Seaport, the downtown Financial District, and through large swaths of East Boston — all around Maverick Square and the northern edge of Logan Airport, across Constitution Beach and low-lying sections of Orient Heights. With 2.5 feet of sea-level rise and a 5-foot surge, only Jeffries Point, Eagle Hill, and the elevated portion of Orient Heights remain dry.

The flooded areas, Estrella-Luna explained, were largely those where landfill had been placed to connect the five islands that were joined to create East Boston, and the un-flooded areas were the hills that were the highest points of those islands. Essentially, rising waters could unmake the connections that created the neighborhood. Rising waters around East Boston could also be damaging to the environment due to the number of industrial sites there and across the Chelsea Creek that contain potential contaminants such as road salt and heating oil.

At the presentation last year, Victoria Wolff, director of sustainable cities at the Urban Ecology Institute, said that while efforts to mitigate the effects of sea-level rise are important, it’s already too late to halt the process of climate change. It’s therefore necessary, she said, to consider not just mitigation but also adaptation, and different areas have different adaptive capacities.

“It’s not just about the math. It’s not just where is the water going to be deepest,” Wolf said. “It’s also the sensitivity.” She offered as an example the difference between a soccer field that would have to be closed temporarily but would be usable again after irrigation and a senior living facility with electric units in the basement.

Different communities have different adaptive capacities as well, she said. Wealthy landowners building beach homes have the ability to adapt the structures to changes in a way that an impoverished population living in shacks near the shoreline doesn’t.

Wolff detailed several types of adaptations that can be made, depending on the site. There are hard, engineered barriers, such as sea walls and revetments — rough but often porous barriers placed on existing slopes to both keep out encroaching water and prevent erosion of the land. Such barriers can be beneficial but can also negatively affect local ecology.

Another option is landscape flood mitigation, which uses naturally occurring or engineered landscape features such as mounds or vegetation to block or redirect water flow for protection of vulnerable areas. Another is flood-resilient building design, which involves engineering buildings so they aren’t affected by flooding.

The final options Wolff described were land-use planning and policy tools — using urban planning and zoning to designate uses so that vulnerable lands are developed for purposes that won’t be permanently damaged by temporary flood. As an example, she offered East Boston’s Piers Park, which she said could be flooded by the combination of rising waters in Boston Harbor and storm conditions but would be usable again after some cleanup and time to dry out.

She said there were three categories of adaptation strategies — reactive, proactive, and spontaneous — and that while proactive adaptations that plan ahead for future events are likely to be most beneficial, but a mix of actions may be combined.

“It’s not a one-size-fits-all solution by any means, and even on a particular site, it’s not necessarily that you rely entirely on one solution,” she said. “You want a stakeholder-driven mix.”

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