The Gulf of Maine is an international watershed in the North Atlantic stretching north from Provincetown at the tip of Massachusetts Bay in the Commonwealth of Massachusetts to Cape Sable on the Bay of Fundy in the province of Nova Scotia in Canada. For over 13,000 years, the Gulf has been developed around access to the coast for fishing, trading, and recreation. Today, these coastal development patterns put the cultural landscapes, economies, communities, and aging infrastructure systems along the Gulf at risk.
Climate Futures on the Gulf of Maine uses place-based scenario planning to illustrate the risks, vulnerabilities, and plausible futures for ten infrastructure systems along the rim of the Gulf. Place-based scenario planning is a method of long-term strategic planning that creates representations of multiple, plausible futures that are used to inform decision-making in the present. While complementary to probabilistic models used to forecast future vulnerabilities, scenario-based planning shifts emphasis from statistical probability to ways of thinking about the future. The goal of place-based scenario planning is not to predict the most likely outcome, but to reveal biases and blind spots in complex and non-linear situations.
Climate Futures uses the medium of landscape representation to surface the cultural value systems embedded in existing infrastructural systems, and position landscape as a driver when evaluating design from individual infrastructures to the Gulf of Maine watershed.
Infrastructure > Rail
SALMON RIVER RAILWAY BRIDGE
Truro, NS
B2N 4A5
Canada
The Salmon River Railway Bridge carries the Ocean Line of Via Rail, the primary east-west passenger railway in Nova Scotia, over the Salmon River between the Towns of Truro and Bible Hill on the unceded land of the Millbrook First Nations People, a Mi’kmaq community. 1 2 The girder 3 bridge is supported by one stone pier and abutments on either side of the Salmon River.
The Town of Truro is known as the Hub of Nova Scotia for its position as a crossroads that first linked the deepwater port of Halifax to Montreal by rail in 1876, connecting the British Maritime Provinces with the Provinces of Upper and Lower Canada. 4 The bridge, constructed in the Salmon River floodplain, provides a critical link for rail travel from Montreal in Quebec province through New Brunswick to Halifax and destinations in eastern Nova Scotia.
Like the railway bridge, the Town of Truro was developed along the Salmon River, an estuary whose outlet lies in Cobequid Bay at the northern reaches of the Minas Basin, itself an inlet of the Bay of Fundy. The Bay has an extreme tidal range 5 which create tidal bores, 6 which have caused devastating flooding during major storms in the past since the region was colonized by French Acadians in the 1600s. 7 8
To produce arable farmland, French Acadians constructed a network of dykes 9 across the Bay of Fundy and drained saltmarshes. To minimize flooding, the Acadians also constructed aboiteaux 10 to discharge freshwater flows from rivers. This system of dykes and aboiteaux are still in operation, and maintained by the Nova Scotia Department of Agriculture. 11
Today, this dyke system protects the low-lying development in Truro, which urbanized after the railroad development in the late 1800s, despite a documented record of flooding from rainwater accumulation, high tides, and ice jams. 12 13 In 2012, after a major storm, representatives from the County of Colchester, Town of Truro, Millbrook First Nation, and Provinces of Nova Scotia joined together to produce a comprehensive flood risk assessment and produce forty potential solutions to flooding. These solutions were digitally modeled and tested against extreme rainfall, tide, sedimentation, and ice events using data collected by engineering, consulting, and educational teams. 14
The stakeholders opted for a managed retreat solution to realign and shorten the dike, remove aboiteaux, and restore 93 hectares of salt marsh to provide habitat and mitigate against flooding. The Committee then adopted a recommendation that all future planning and regulatory processes are designed to avoid further floodplain development. 15
The Salmon River Railway Bridge lies upstream from the adaptation project, and, upon its completion, will be protected from flooding by the restored marshland. 16 Beyond the physical and ecological benefits of the project, the Joint Flood Advisory Committee stands as a social model to produce comprehensive and accurate flood models and choose an adaptation landscape that moves beyond the status quo (rebuilding resilience infrastructure like dikes higher) in partnership with community members, governments, and educational institutions in a region that has not enacted climate change adaptation policies. 17
While the project is still under construction, the participatory process modeled by the Joint Flood Advisory Committee and uncertainty around Truro’s long-term flood adaptation strategy provides an opportunity to consider realigning the train tracks and restoring additional area in the Salmon River floodplain, or proactively reinforcing and upgrading the tracks to ensure continued passenger rail service to eastern Canada.
Scenario 0: Storm of the Century 2030
The banks of the Salmon River are saturated and collapse the track, plunging the railway into the river. No one is injured, but the track collapse pauses Via Railway service east of Truro indefinitely.
Scenario 1: Fortified Systems
A reinforced bridge is installed across the Salmon River, ensuring rail access east of Truro to Halifax.
Scenario 2: Catchment Commons
A riparian buffer is planted along the Salmon River. The railway is diverted north to a narrower crossing of the Salmon River. The realignment is part of a broader plan that takes three years to complete, during which time train service is cancelled while the fleet is electrified.
International Watershed | Gulf of Maine |
Ocean Drainage Area | Atlantic Ocean |
Major Drainage Area | Maritime Provinces |
Sub Drainage Area | Bay of Fundy and Gulf of St. Lawrence |
Sub Sub Drainage Area | Salmon (N.S.) |
“Millbrook First Nation,” Millbrook Band, accessed June 10, 2025, www.millbrookband.com/about.
The Mi’kmaq people constructed their settlements away from the Salmon River floodplain, which they acknowledged as unsafe for permanent settlement. CBCL Limited, “Flood Risk Study: Joint Flood Advisory Committee County of Colchester, Town of Truro, and Millbrook First Nation” (Truro, NS: Joint Flood Advisory Committee, 2017):1, truro.ca/documents/adm/1677-truro-flood-risk-study-1/file.html.
A girder is a horizontal support beam. They are commonly used to build bridges.
The first railway line was constructed from Halifax to Truro between 1854 and 1858 to transport goods from the eastern Maritime Provinces inland, connecting the Atlantic to the Bay of Fundy. In 1876 the line connecting Halifax to Montreal through Truro was completed and operated by the Intercolonial Railway of Canada (IRC), one of Canada’s first Crown Operations. The IRC operated until 1918, when it became part of Canadian National Railways. In 1977, Canadian National Railways created a separate corporation, Via Railways, for its passenger services. See Robert F. Legget, Railways of Canada, Railway Histories of the World (London: Newton Abbot, 1973).
Tides in the Bay of Fundy can range as much as 50 feet (15 meters) due to the Bay’s length, depth, and shape. See Philip W. Conkling, ed., From Cape Cod to the Bay of Fundy: An Environmental Atlas of the Gulf of Maine (Cambridge, MA: MIT Press, 1995), 49-50.
The Fundy Discovery site, located in Truro, defines a tidal bore as “a tumbling wavefront which moves upstream in a river, announcing the arrival of an incoming tide.” The highest tidal bores in the Salmon River occur during perigean-spring tides when the Moon is in its new or full phase and closest to Earth. “Tides & Tidal Bores,” Discovery Site Fundy, accessed May 16, 2025, fundydiscovery.ca/tides-tidal-bores.
The 1869 Saxby Gale was a Category 2 hurricane that caused massive flooding across the Gulf of Maine.
Norm Catto, “Atlantic Canada’s Tidal Coastlines: Geomorphology and Multiple Resources,” in Landscapes and Landforms of Eastern Canada, ed. Norm Catto and Olav Slaymaker (New York: Springer, 2020), 401–31.
The American English spelling dike and British English spelling dyke are used in different publications about the French Acadian system. This report adopts the spelling used in sources, and therefore both spellings are used.
Aboiteaux are a culvert and sluice gate system. The gates open during low tide to discharge freshwater and close during high tides to prevent tidal flooding. Kate Sherren et al., “Coastal Infrastructure Realignment and Salt Marsh Restoration in Nova Scotia, Canada,” in Responding to Rising Seas: OECD Country Approaches to Tackling Coastal Risks (Paris: OECD Publishing, 2019), 111–35.
Jeffrey Marvin and Alexander T. Wilson, “One Dimensional, Two Dimensional and Three Dimensional Hydrodynamic Modeling of a Dyked Coastal River in the Bay of Fundy,” Journal of Water Management Modeling 24 (2016), https://doi.org/10.14796/JWMM.C404.
Ice jams result from ice breakup during the spring and during winter thaws. Combined with rising water levels from spring snowmelt, midwinter thaws are often accompanied by substantial rainfall, which results in a rapid increase in water levels and ice jams in rivers. CBCL Limited, “Flood Risk Study: Joint Flood Advisory Committee County of Colchester, Town of Truro, and Millbrook First Nation” (Truro, NS: Joint Flood Advisory Committee, 2017), truro.ca/documents/adm/1677-truro-flood-risk-study-1/file.html, 32.
Comprehensive studies of Truro’s flooding issues were completed in 1971, 1983, 1988, 1997, and 2006, focused on hard resilience infrastructure solutions, including raising dykes, constructing storage dams, a tidal dam across the bay, ice control berms, and channelizing the river. CBCL Limited, “Flood Risk Study: Joint Flood Advisory Committee County of Colchester, Town of Truro, and Millbrook First Nation” (Truro, NS: Joint Flood Advisory Committee, 2017), truro.ca/documents/adm/1677-truro-flood-risk-study-1/file.html.
There was no single solution identified under 100 million Canadian dollars that would protect more than 20% of the areas identified as priorities to protect.
Kate Sherren et al., “Coastal Infrastructure Realignment and Salt Marsh Restoration in Nova Scotia, Canada,” in Responding to Rising Seas: OECD Country Approaches to Tackling Coastal Risks (Paris: OECD Publishing, 2019), 111–35.ʻ
While the project is under construction, in 2023, another Via Railway bridge 60 kilometers away from Truro in Millbrook washed out and was replaced with a culvert after 10 inches of rain fell in 24 hours, highlighting the regional challenges in adapting systems like railroads that cross multiple drainage basins. Trains Staff, “Canadian National main line to Halifax washed out by flooding,” Trains, July 23, 2023, www.trains.com/trn/news-reviews/news-wire/canadian-national-main-line-to-halifax-washed-out-by-flooding.
It is also unclear if the project will meaningfully contribute to climate adaptation, because it is not yet clear if the restored marsh will adapt to sea level rise, or simply protect from flooding and reduce erosion. Kate Sherren et al., “Coastal Infrastructure Realignment and Salt Marsh Restoration in Nova Scotia, Canada,” in Responding to Rising Seas: OECD Country Approaches to Tackling Coastal Risks (Paris: OECD Publishing, 2019), 124.
