Taking a first step to understand—and plan for—the impact of sea level rise in St. George

Sea level rise threatens St. George roadways such as this section of Route 131 in Martinsville.

On November 14th members of the St. George community will have an opportunity to hear from representatives from the Island Institute, The Nature Conservancy, the Vinalhaven Sea-Level Rise Committee, and the Midcoast Economic Development District about the possible impact of sea level rise on municipal infrastructure and services. “I hope people will take this threat seriously,” says St. George Town Manager Tim Polky. “The first step is to raise awareness, and then figure out down the road what’s needed to address the issues.”

With its 125 miles of shoreline, sea level rise poses a number of pressing questions for St. George. What are reasonable predictions for how much sea level will rise in the next 20 years? What can we do as a community to protect our municipal infrastructure, ensure first responders can access all residents, and shore up impacted commercial and personal property?

Global sea level has risen by about eight inches since record keeping began in 1880, according to the 2017 U.S. National Climate Change Assessment. However, local sea level rise is accelerating due to two global factors. The first is the warming ocean, because water takes up more space as it warms. This increased volume of water in the Gulf of Maine is the main factor driving the anticipated higher sea levels in St. George.

The second factor adding to more water in our oceans is melting land-based ice sheets and glaciers. Conservation Commission member Dan Verillo says: “We believe that sea level rise is an aspect of climate change that will have an impact in our immediate future, that is, in less than 20 years. Other aspects of climate change are just as important, but sea level rise is not disputed any more. Data suggests that a rise of two feet cannot be avoided even if the world immediately does everything the Paris Agreement demands. Therefore, St. George should prepare for the inevitable.”

A publication by the Island Institute, “Sea Level Rise and Coastal Flooding,” states: “On average, sea levels are projected to rise another one to four feet globally by 2100, but sea level change will vary regionally (2017 U.S. National Climate Change Assessment). The Gulf of Maine is especially susceptible to fluctuations in sea level due to changes in the strength of the Gulf Stream and seasonal wind patterns. Sea levels in the Gulf of Maine are projected to rise faster than the global average.”

According to the National Oceanic and Atmospheric Administration (NOAA), higher sea levels also mean more frequent high-tide flooding, especially due to stronger storms that are happening more often. This high-tide flooding, also called “nuisance flooding,” temporarily leads to road closures as well as overwhelmed storm drains and erosion of roadbeds. For this reason, Polky notes, St. George’s road maintenance plan is already taking future flooding into account.

There are predictions that the sea level in St. George will rise one to two feet by 2040. Most experts agree that by 2100, a year today’s kindergartners will see, at least a four-foot sea level rise in St. George is the most likely outcome. Polky and other town officials expect sea level rise could adversely affect the town’s municipal infrastructure, delivery of emergency services, planning ordinances, natural resources, tax base and local economy.

For the town’s Planning Board, for instance, rising sea level calls into question how best to apply the state-mandated shoreland zoning ordinance both in terms of new construction and in terms of existing structures that begin to enter the zone. In addition, says Planning Board chair Anne Cox, the number of shoreline stabilization projects being proposed seems to be increasing.

“As property owners have experienced higher tides, and storm-driven tides, their land has eroded,” she says. “We on the Planning Board have seen quite a few applications to stabilize the shore by adding some sort of rock “armor.” Sometimes these applications have included plans for re-vegetating behind the rock with mat-forming native plants to help hold the shoreline. I want to learn about the efficacy of these different stabilization projects. For example, I have questions about the effect of one section of shore being armored on neighboring unprotected areas. Does the addition of rock in one area increase the erosion of a neighboring area? Also, we have recently seen one stabilization project being proposed to address a stabilization effort that was inadequate after just seven years. So do these stabilization projects even work with rising sea levels?”

The likely impact of sea level rise and more frequent flooding on the local economy and the town’s budget and tax base is also a particularly thorny topic. First, marine-based businesses, which are a significant part of the town’s economy, could experience significant losses and capital costs. Second, sea level rise may seriously impact private property values—homes on the water, in particular, could lose value as the floodplain encroaches and they are forced to carry expensive flood insurance. Richard Cohen, who is on the St. George Budget Committee, asks, “What’s going to happen to the tax base when homes lose value? We have to look forward 30 years right now.”

The community meeting on sea level rise and its potential impact on municipal infrastructure and services that will be held at the town office on November 14 at 7pm, is intended to be a first step in taking that look into the future. The agenda for this meeting includes presentations by Susie Arnold of The Island Institute on the science of sea level rise and Jeremy Bell of The Nature Conservancy on computer tools for predicting how the St. George coastline will be impacted. Highlights and challenges from other communities tackling sea level rise will be presented by Gabe McPhail, Community Development and Engagement Coordinator for the Town of Vinalhaven and Bill Najpauer from the Midcoast Economic Development District. This meeting is supported by the Budget Committee, Conservation Commission, Planning Board, Select Board, St. George Municipal School District, St. George Community Development Corporation, St. George Volunteer Fire and Ambulance Association, and the Island Institute and The Nature Conservancy.

Resources:

Quoted paper from Island Institute: Sea Level Rise and Coastal Flooding The Basics for Maine Communities

http://www.islandinstitute.org/sites/default/files/II Pager – Sea Level Rise.pdf

http://www.islandinstitute.org/climate-impacts

Knox County Mitigation Plan

Is Sea Level Rising? https://oceanservice.noaa.gov/facts/sealevel.html

NOAA Sea Level Rise Viewer https://coast.noaa.gov/slr/

https://oceanservice.noaa.gov/facts/nuisance-flooding.html

PHOTO: Anne Cox

Print Friendly, PDF & Email

Leave a Reply

Your email address will not be published. Required fields are marked *