14-mile dike could protect Greater Boston from sea level rise

14-mile dike could protect Greater Boston from sea level rise

Barrier would run from Cohasset to Swampscott

A RECENT story in the Boston Globe, with the headline “Floods seen as warning of Boston’s future,” described how sea level rise and storm surge effects predicted for later in the century made their appearance during last week’s bomb cyclone. The article also mentioned various studies on what to do about sea level rise planned or underway by the city of Boston, its Green Ribbon Commission, and the University of Massachusetts.

We submit that the options explored by these studies share a glaring deficit – Boston and adjacent metropolitan cities and towns will not be completely protected. Because these municipalities are located in the metropolitan Boston estuary (the outlet for the Charles, Mystic, and Neponset Rivers, among others), nearly every option studied so far will be circumvented by higher sea levels and storm surges via Revere and Lynn to the north and via Nantasket Beach to the south. The studies also ignore river flooding altogether.

We offer a more ambitious protective option than any proposed so far by the local governments of the metro Boston estuary. We call it Metro Boston DikeLANDS, and we believe it is more practical and creative and has the potential to provide a significant return on the enormous investment required, unlike the other options discussed.

The metropolitan Boston estuary is uniquely different from many others around the nation. It is protected on its flanks by the shoulder highlands of Swampscott and Cohasset. The Metro Boston DikeLANDS proposal takes advantage of the estuary’s unique geological characteristics. 

Our idea is an expansion of one proposed originally by Antonio DiMambro when he won the 1988 Boston Society of Architects competition. We propose building a 14-mile dike barrier between the shoulder highlands of Cohasset and Swampscott. The dike would be located some eight miles out from Deer Island, complete with residential and commercial developments, windmills, solar collector farms, and recreational areas. A simple dike barrier with a 200-foot-wide top and reaching 120 feet from seafloor to storm-surge top would require some 246 million cubic yards of material. Bi-directional locks could provide access for all crafts, protecting Boston’s commercial activity and its waterfront integrity.

The new dike system will prevent storm tides from inundating the entire metropolitan estuary while allowing rivers to discharge their water into a harbor reservoir capable of holding more than 10 billion gallons of river-fed water. The gradual transformation of the reservoir into a fresh-water lake could permit it to act as a source of fresh water for the drinking water needs of southeastern Massachusetts communities. The drinking water supplies of those communities are increasingly threatened by rising sea levels, which are making groundwater increasingly brackish.

By lowering the reservoir level to half the current tidal range, the cherished Boston Harbor Islands and their recreational potential would be protected. (With the new dike system, however, the islands eventually would be surrounded by fresh water rather than sea water.)

At a cost of $100 per cubic yard, with two bi-directional shipping locks of $500 million each (plus soft and contingency costs), this macro-engineering and macro-economic project would probably cost between $30 billion and $50 billion. The 200-foot wide top of the 14-mile stretch would create 68 acres of new dike lands, which in turn would need to be supported by a complete infrastructure system of water, sewer, electricity, and transportation (high-speed mag-lev trains to connect the north and south shores without going through downtown are a possibility). New all-electric buildings would become the customers for renewable energy provided by new windmills, which would take advantage of the offshore winds, and solar-tracking photovoltaic installations.

In many respects, the Metro Boston DikeLANDS proposal would bring economic as well as ecological sea change parameters in line with the resiliency required to meet the challenges of rising sea levels and climate change impacts.

A project of this scope requires major public as well as private support to overcome all the foreseeable environmental changes and regulatory obstacles to such a large project. The project could help pay for itself if the newly-created, flat-top area of the dike, amounting to some 68 acres, was sold as waterfront property at between $3 and $7 million per acre. That would raise between $100 billion and $400 billion (after return on invested capital) and possibly more if the dike’s landward slope facing the metro Boston estuary were also developed for terraced housing. Still more money could be raised if additional expansion zones or peninsulas were created along the dike barrier.

Meet the Author

Peter Papesch

Architect/developer, Retired
Meet the Author

Franziska Amacher

Architect, Focus on sustainable communities
Meet the Author

A. Vernon Woodworth

Architect and code consultant, AKF Group
Boston began as a slight peninsula and has grown steadily in step with the needs of the times. Our enterprising forebears – investors as well as policymakers – had the vision to fill tidal flats to create Boston’s Back Bay in the 19th Century. Their descendants are equally capable of undertaking a comparably visionary project in the 21st Century, one which would serve double duty as protective flood system and newly created waterfront property, reshaping and enhancing the entire metropolitan area.

Peter Papesch is a retired architect-developer and educator. Franziska Amacher is an architect with over 25 years of promoting and designing sustainable communities. A. Vernon Woodworth is an architect and code consultant with AKF Group, and a faculty member at the Boston Architectural College. All three are members of the Boston Society of Architects, which is a chapter of the American Institute of Architects.

  • Ed Cutting, Ed. D.

    It would create a stagnant cesspool — it is the massive amount of water that moves four times a day with the tides that has facilitated the harbor’s recovery. There’s still 300 years worth of pollution on the bottom.
    In addition to the organics, there are heavy metals, radioactive & chemical wastes. And the rivers themselves are not pristine.

    Currents in the Gulf of Maine rotate in a counter-clockwise direction. Putting a barrier here could well destroy Cape Cod — literally.

    A freshwater lake would also cause actual climate change — as a confined lake would heat & cool in a way the ocean can’t, we’d have hotter summers and colder winters.

    • QuincyQuarry.com

      Even the currently Trumped EPA will likely not approve turning a major chunk of greater Boston Harbor into a fresh water lake. The windmills, however, do offer an amusing homage to Cervantes.

  • Michael Tyrrell

    This scheme has laudable features. The potential for wind farms and tidal induced hydro-electric power (was that mentioned?) are exciting, but implementation would be far more costly, with environmental protections outweighed by impacts. What I like about the DiMambro Scheme, with its adaptation of the islands, is it’s ability to protect the lowest lying and most intensely invested upon vital infrastructure. Also like it’s potential to create new development parcels within the core city by relocating port-container shipping to the outer rim of the harbor. One challenge in that latter scenario are the service roads -Quincy and Winthrop would have to be made equal partners. https://uploads.disquscdn.com/images/3c5dfd5a1a1795d2e06e272e7db29bcaa64a061b3147631f8931ccc632810126.jpg

    • QuincyQuarry.com

      Why would Winthrop and Quincy agree to cooperating with a plan that does next to bupkis to protect their low-laying districts, if not also could well increase the impact of storm surge damage upon same?

      • Michael Tyrrell

        Thank you for that incisive question. My answer may not be too palatable:
        The flood control system would be designed to protect mainly the vital infrastructure of Central Boston -meaning the MBTA and Artery Tunnels, Logan Airport, and the disproportionately low-lying and “big ticket” investments that define Downtown Boston. That’s not to say outlying towns shouldn’t be protected -they should. However those areas will need resilliancy strategies proportional to what they bring to the regional economy. That said, Winthrop (which would be fully protected in the DiMambro scenario, actually) and the City of Quincy (whose CBD is on higher ground) could draw significant revenue from a joint venture on a new and expanded port of Boston (kinda like the Port Authory of NY & NJ, but smaller). The intent is to protect the vital core infrastructure, but use the new barrier facility to expand and improve local port functions. Quincy would be very lucky to be part of that potential mix. https://uploads.disquscdn.com/images/019c48b935e0591c893d441ae857bae264112728e297bc840a106014fbe41b00.jpg

      • Ed Cutting, Ed. D.

        Forget storm surge, this would increase Quincy’s tides, causing it’s low-lying areas to be flooded twice daily as the eastbound water is funneled higher on each side. Just look at the map.

        • QuincyQuarry.com

          While not versed in hydrology, an additional daily impact from “regular” tides north and south of this more modest proposal would appear to be minimum at best during high tide events with no concurrent significant onshore wind.

          Simply put, the removal of some relative modest amount of inner harbor storage capacity via this plan is not going have much of impact upon the total holding capacity of Massachusetts Baby, much that of the nearby Atlantic Ocean, during high “regular” tide events.

          Rather, and again, it is major storm surge events that pose the most significant problems with this lesser plan. The problems include both a limited area protected as well as the need of additional diking or berming needs on dry land both north and south of proposed in-harbor diking so as to mitigate flanking leakage.

          In particular, just the considerable additional on dry land infrastructure needed south of the Squantum access point onto the Moon Island causeway to high ground somewhere in North Quincy to develop a barrier will face considerable local opposition given but minimal benefit to Quincy. Further, this plan would impose increased vehicular traffic in North Quincy given the proposed relocation of some seagoing shipping facilities inside of the harbor dike between Long and Moon Islands.

      • Michael Tyrrell

        Quincy Quarry,

        I thought I posted this yesterday. Apologies in advance for any redundancy:
        The DiMambro scheme would ensure that low-lying, inner core Boston -its vital infrastructure (Logan Airport, the MBTA and Artery Tunnels, etc., and hence the broader economy) would go undisrupted. Using a combination of natural and man-made features to hold back surges AND, potentially, expand and/or relocate the Port of Boston away from the Inner Harbor, the plan offers more than simply intermittent flood protection.

        Fortunately, Quincy’s central business district is located on higher ground, but like most of communities along the Massachusetts shore line, it will need to adopt resilliancy measures to cope with future storms and flooding -barriers cannot be built everywhere, and Boston’s odd combination of major infrastructure and low elevation make it a dire priority for “big ticket” protection measures.

        However, to your question, the incentive for Quincy and Winthrop (the latter would in fact be fully protected by this system) is the port relocation and expansion concept. Such would only be possible through a joint venture with both cities (like the Port Authority of New York and New Jersey, but smaller). Depending on service-road access provisions, both Winthrop and Quincy could receive new, substantially large revenue streams if such a facility/venture were agreed to.

        • QuincyQuarry.com

          Mr. Tyrrell,

          You might care to note that it appears that Commonwealth monitors comment replies after some number of back and forth follow-up’s. In this instance, I received notice of what I suspect was your first follow-up – but somehow or other that post appears to have gone MIA.

          In any event, as for the more modest DiMabro proposal, I do appreciate its essentially triage rationale.

          What is not clear, however, are the benefit/cost outcomes – especially as regards its impact given its also needed land-based facilities.

          In the case of just Quincy, not only would it likely entail the conversion of considerable acreage of currently mostly residential property for use as protective barrier, a further and far larger chunk of local residential property outside of the barrier would still remain unprotected.

          A ballpark eyeball of the local flood zone map would suggest several to five square miles of developed land in Quincy would be left unprotected.

          As such, barring Hurricane Katrina or Sandy levels of storm damage first occurring, I just cannot imagine a basis for a local willingness to agree with accepting the massive impacts of the DiMabro proposal – and by then horse would be both out of the barn as well as swept out to sea.

          Also note that Quincy Center’s higher ground business district is not exactly high value as well as parts of both the Red Line and a busy Commuter Rail would likely still remain vulnerable absent further hardening.

          Granted, port operations revenue could come to Quincy c/o implementing the DiMabro proposal, but such would only come as a result of even further impact on local residential neighborhoods.

          Plus, in the meanwhile, the former Fore River shipyard now has even more available cargo handing capabilities given that the new Fore River Bridge allows access by New Panamax ships. Tidal impact vulnerability of this venue notwithstanding, its shipping capacity is already being enhanced as well as can made flooding event resilient for short money.

          And finally, no plan should be considered absent Dutch input. After all, Holland knows better how to counter the tidal events better than any other country in the world.

          • Michael Tyrrell

            QunicyQuarry, thank you for the thoughtful reply. I forgot about Fore River and its potential, and I concede that accessing Long Island for port activity would be very difficult politically. That said, the region’s core city remains (and will become increasingly) vulnerable.

            For me the DiMambro Scheme is the right scale of intervention. It would require “adjustments” to certain neighborhoods near Squatum and Wollaston Beach. Northly, the scheme requires an additional two-mile stretch running past Beachmont, up to the Pines River in Revere. So its not a simple fix, but a conceivably doable option with regard to protecting vital infrastructure.

            I am not a hydrologist either -so much study is needed, and if I’m not mistaken Mayor Walsh has undertaken such. However, if this facility were built the tidal flows would remain about the same (its not a dam) and its flood gates would only shut during emergency weather events/tidal surges/hurricanes.

            I agree the Dutch have this stuff down, and we should follow their example(s). Here’s a link on the DiMambro “Safety Belt” concept: https://architectureboston.wordpress.com/2010/04/28/the-high-tide-of-opportunity/


  • TheSalemCat .

    Here’s a modest proposal – one that Houston seems to be finally adopting ….

    Why not simply follow Nature’s Lead, and NOT BUILD on Wetlands and Beaches ?

    • Joel C. Payne

      Boston was a wetlandso under your plan Boston would still be a tiny village.

  • Piranharama

    This is THE DUMBEST idea I have heard in a long time. You guys should stick to designing buildings (and I’m not even sure you’re good at that…).

  • How about they just drain that lake and extend the state’s landmass further out into the bay? Think of all the new development opportunities? Plus, you’d finally have room for a new Fenway Park AND you could move Gillette Stadium into Boston proper. And how about a monorail while we’re at it? Did someone say dome?

  • tom

    I have an idea that’s more practical and more likely to be built – just raise all the buildings in the Boston Metro area by 10 feet!

    I predict the cost for that would be between $30 and $50 billion. Not.