The Lost City of Portlantis? Researchers, city officials talk about sea level rise

Next Friday, Feb. 24, University of Southern Maine is hosting a presentation and community discussion about how sea level rise over the next several decades could affect the city of Portland. The New England Environmental Finance Center has recently completed a study on sea levels and storm surge potential in the city’s Back Cove area.

This is how the Back Cove area would look, facing west, after one meter of sea level rise. The image was released in 2006 by the Natural Resources Council of Maine.

Among the speakers will be Mayor Michael Brennan, New England Environmental Finance Center Director Sam Merrill and Peter Slovinsky of the Maine Geological Survey.

Here are a couple of paragraphs about the Friday activities as provided by USM’s Muskie School of Public Service, which is hosting the event at the Wishcamper Center:

The NE/EFC efforts follow a July 2011 resolution by the Portland City Council supporting the development of a sea level rise adaptation plan. Audience members will have the opportunity to help frame the adaptation planning process through breakout sessions and open discussion after the presentation. Interested stakeholders are encouraged to attend and provide input.

The NE/EFC analysis is based on simulation modeling from the center’s Coastal Adaptation to Sea level rise Tool (COAST), an assessment tool that assists municipalities in evaluating the costs and benefits of adaptation actions in response to threats of sea level rise and storm surge. A review of COAST results will show the prospective losses in Back Cove real estate values under a variety of sea level rise, storm surge, and adaptation scenarios.

This is a subject my friend and Maine Public Broadcasting Network newsman Tom Porter, the dapper fellow with the British accent on the radio show Maine Things Considered, reported on this past week.

Tom talked to Merrill, Slovinsky and City Councilor David Marshall for his piece, and Slovinsky told him researchers plotted out what portions of Portland would look like after sea level rises ranging from a foot to six feet over the next century.

Slovinsky also noted more immediately, storm surges and high tides could more regularly creep up on low-lying areas of Maine’s largest city.

Merrill told Tom local investments adding up to $100 million in the short term — presumably to raise structures over a higher flood line, among other things — could save citizens $400 million by 2050.

Marshall noted in the MPBN segment that building code changes could be one way the city prepares for the higher water marks, pointing out that in Hamburg, Germany, buildings are required to be built at least six feet above sea level.

This whole conversation reminds me of a 2006 report released by the Natural Resources Council of Maine depicting the 20 coastal Maine communities most at risk as the sea level rises over the next half century to a century.

At that time, the NRCM, using University of Maine Climate Change Institute help, claimed a three-foot sea level rise by 2100 is about a “middle range of what might occur due to global warming” and the steady melting of the polar ice caps. Three feet works out to just under one meter, for reference.

In addition to the computer-generated flood image posted above, here’s another map NRCM released to show how much of Portland would be under water with a one-meter sea level rise (in red) and a six-meter rise, which would be a high end estimate for the year 2100.

Seth Koenig

About Seth Koenig

Seth has nearly a decade of professional journalism experience and writes about the greater Portland region.