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Coastal infrastructure realignment and salt marsh restoration in Nova Scotia,
Canada
This chapter describes a project to realign a section of the North Onslow dyke near
Truro, Canada. This project was intended to achieve the multiple goals of reducing dyke
maintenance costs, enhancing protection of public and private infrastructure, and
enhancing resilience to climate change through the restoration of a coastal flood plain.
Authors: Kate Sherren1, Tony Bowron2,3, Jennifer M. Graham3, H. M. Tuihedur
Rahman4,1, Danika van Proosdij4
1 School for Resource and Environmental Studies, Dalhousie University, Halifax
2 Department of Environmental Science, Saint Mary’s University, Halifax
3 CB Wetlands and Environmental Specialists (CBWES Inc.), Terrance Bay
4 Department of Geography and Environmental Studies, Saint Mary’s University, Halifax
Acronyms
DFO Department of Fisheries and Oceans (Federal)
DFAA Disaster Financial Assistance Arrangements
ECCC Environment and Climate Change Canada
FDRP Flood Damage Reduction Program
FRIIP Flood Risk Infrastructure Investment Program
IBC Insurance Bureau of Canada
ICSP Integrated Community Sustainability Plans
MCAAP Municipal Climate Change Action Plans
MPS Municipal Planning Strategies
NDMP National Disaster Mitigation Program
NRCan Natural Resources Canada
NSDA Nova Scotia Department of Agriculture
NSDE Nova Scotia Department of Environment
NSLF Nova Scotia Department of Lands and Forests
NSTIR Nova Scotia Department of Transportation and Infrastructure Renewal
SLR sea level rise
SMU Saint Mary’s University
Pre-press unpaginated version as submitted to OECD – further edits have been undertaken by OECD:
http://oe.cd/rising-seas
Cite as: Sherren, K., Bowron, T., Graham, J. M., Rahman, H. M. T., and van Proosdij, D. 2019. Coastal
infrastructure realignment and salt marsh restoration in Nova Scotia, Canada. Chapter 5 in Responding to
Rising Seas: OECD Country Approaches to Tackling Coastal Risks, p. 111-135. OECD Publishing:
Paris, France.
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1.1. Context
1. Canada has the world’s longest coastline, bordering three oceans, and is thus
highly exposed to sea level rise (SLR) (Lemmen and Warren, 2016). Approximately 38%
of Canada’s population lives within 20 km of a coast (Manson, 2005). Climate impacts
and risks vary across the three coasts in Canada (Lemmen et al., 2016). The Arctic coast
comprises 70% of Canada’s shoreline, comprising mostly small villages of largely
Indigenous inhabitants, where sea levels are expected to drop, but where livelihoods and
cultures will be affected by declining sea ice, melting permafrost and coastal erosion and
instability. The Pacific coast is dominated by the large population centres of Vancouver
and Victoria, both located in the Fraser Lowland area that is expected to see the highest
relative SLR for the region. Lemmen and Warren (2016) note, however, that the Pacific
region faces higher vulnerability to storm surges than SLR.
2. The Atlantic coast hosts a few small cities but many towns and villages, including
unincorporated shoreline developments, all expected to be affected by and vulnerable to
SLR and increasingly extreme weather events (Lemmen and Warren, 2016). Examples of
climate adaptation planning are coming from especially vulnerable places, such as Les
Îles-de-la-Madeleine in the Gulf of St. Lawrence, which has no alternative but to engage
in coastal retreat (McClearn, 2018). Nova Scotia is another jurisdiction with significant
exposure to SLR, and numerous local innovations. This chapter describes one such
project in Nova Scotia, a dyke realignment and tidal wetland restoration project that was
largely achieved because of its alignment with government policies unrelated to climate
such as wetland compensation and dyke divestment.
1.2. Nova Scotia: a coastal jurisdiction
3. Nova Scotia is a Canadian province vulnerable to SLR due to its geography and
geologic history. The province’s 55 000 km2 are dominated by an isthmus and the large
island of Cape Breton (~10 000 km2), along with thousands of smaller islands. All of the
province is located within 67 km of the coast (Chesworth, 2016). There are 13 different
coastal ecosystems in Nova Scotia, from the expansive intertidal mudflats and salt
marshes of the Bay of Fundy coast, to erosive cohesive bluffs on the Northumberland
coast (Savard et al., 2016), to complex rocky shores of the Atlantic coast. Its ~7,600 km
coast is highly corrugated, with a complex drainage pattern including tens of thousands of
lakes and wetlands, its climate is temperate, and it is relatively low-lying, peaking at 536
metres in Cape Breton Highlands National Park.
4. Geologically, like the rest of the Atlantic provinces, Nova Scotia is undergoing
crustal subsidence, or glacial isostatic adjustment, dipping as more northerly and central
areas of Canada spring back from released pressure after glaciation (Greenan et al.,
2015). Richards and Daigle (2011) project that by 2100 Nova Scotia will become warmer
but also wetter and with precipitation coming more frequently via extreme events. In the
provincial capital of Halifax, this is projected to result in extreme wave events during
storms under all climate scenarios tested (Xu and Perrie, 2012). Relative sea level rise
projections (incorporating vertical crustal movement) based on the RCP 8.5 scenario of
the 5th Assessment Report of the IPCC (2013), modelled by James et al. (2014) predict
an upper bound of 1.30 m (median 0.90 m) by 2100. In the upper Bay of Fundy, these
projections will most likely be close to or perhaps exceed the upper bound due to
amplification of tidal range that is also occurring (Greenberg et al., 2012). This area
already has the highest tides in the world.
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5. Nova Scotia is already seeing the effects of subsidence, independent of climate-
driven change; estimates of increases from the Marine Environmental Data Service range
from 24 to 32 cm per century across four coastal communities in the province (CBCL
Limited, 2009). Increases in extreme weather events and storm surges are of primary
concern to coastal residents and decision-makers in the province (Rapaport et al., 2017).
6. Nova Scotia’s coasts are sites of long human occupation. Nova Scotia’s first
people, the Mi’kmaq, relied on coastal settlements for fishing in the spring and summer,
moving inland to hunt for food and furs in the fall and winter (Hornborg, 2008). Records
of early contact with European explorers and fishers around the busy Atlantic coast date
back to the 1500s, but it was in the 1600s that permanent French settlers arrived, later to
be called Acadians. Acadians and later settlers converted most of the rich coastal
wetlands of the Bay of Fundy coast to farmland by constructing dykes including one-way
drains that allow freshwater to flow out at low tide but close at high tide to keep salt
water out (called aboiteau, aboiteaux if plural) (Bleakney, 2004; Butzer, 2002). Dyking
practices, combined with contemporary development activities (i.e., causeway
construction), resulted in the conversion and loss of nearly 85% of tidal wetlands in the
Bay of Fundy (Hanson and Calkins, 1996).
7. Coasts remain a critical part of Nova Scotia’s identity and economy. The province
has only 920 000 inhabitants, 40% of whom live in the capital area of the Halifax
Regional Municipality (HRM), and over 60% of whom live within 20 km of the coast
(CBCL Limited, 2009). Though most (77%) of the coast is undeveloped, it is also mostly
privately owned (87%) and there is significant pressure in and near its many ports,
harbours and estuarine settlements like Truro (CBCL Limited, 2009). Nova Scotia grew
from the coast inward, and most development flanks coastal roads. While a few industries
important to GDP rely specifically on coastal resources (e.g. agriculture, fisheries,
shipping), most industries rely on infrastructure such as transportation networks and the
utilities such as powerlines that tend to follow coasts (CBCL Limited, 2009). As
transportation infrastructure improves, commuting time decreases, expanding
development outward from urban centres and putting additional pressure on coastal areas
(Millward, 2005).
8. Nova Scotia’s coastal residents are also vulnerable demographically, in part due
to aging in rural areas (Gibson et al., 2015), but also due to seasonal population changes:
summer amenity in-migration (due to relatively cheap waterfront) and winter out-
migration (snowbirds (Northcott and Petruik, 2011)). Seniors (those older than 65) are the
fastest growing demographic group in Nova Scotia, comprising 15% of the population
overall (CBCL Limited, 2009) but more than a quarter and sometimes over 30% of the
population in many rural, coastal places, because of lower birth rates, youth out-
migration, retiree influxes (including returnees) and lengthening life spans. (Krawchenko
et al., 2016, Coulombe, 2006, Newbold, 2008, Foster and Main, 2017). These older
residents are often dependent on services that are themselves vulnerable to SLR (Manuel
et al., 2015).
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10. The Nova Scotia Department of Agriculture (NSDA) is responsible for the
management and maintenance of the province’s 260 aboiteaux (one-way drains used for
land reclamation) and 241 km of dykes. The resource (human, financial) and engineering
requirements to maintain and upgrade this infrastructure stock to withstand SLR exceeds
the Department’s current capacity. NSDA is mandated to protect agricultural landscapes,
but a significant portion of the 17 400 ha of land they protect is now used for non-
agricultural practices and developments. NSDA is prioritizing which dykelands could
potentially be decommissioned (breached) and restored to salt marsh (Bowron et al.,
2012, van Proosdij et al., 2014). In some of these cases, where built assets would still
require protection, the construction of new, shorter, dykes built to modern specifications
(including SLR projections) is being considered (MacDonald et al., 2010), a process
called dyke realignment.
11. Reducing dyke infrastructure and restoring provincially significant wetlands has
additional benefits beyond ensuring the protection of core agricultural areas and critical
infrastructure. These include climate mitigation benefits, in terms of sequestered carbon
in salt marsh, often called “blue carbon” (McLeod et al., 2011), as well as climate
adaptation benefits (Wollenberg et al., 2018). Nine such restorations have been done in
Nova Scotia since the first at Cheverie in 2005 (CBC, 2010), including five culvert
replacements and four dykes breached, covering a total of 98 hectares. A further nine are
pending or in construction (five dyke, four road) representing an additional 338 hectares.
12. The small town of Advocate Harbour provides a useful exemplar of the
sensitivities that exist in discussions of dyke futures, which so many Nova Scotia towns
will have to face in coming years. A meeting was held in early 2018 to discuss the future
of the agricultural dyke that protects numerous homes and businesses in Advocate
Harbour (Cole, 2018). Local preferences are strongly for dyke reinforcement, as one
citizen argued, “... they have to be very careful that the future of the community is not
placed under a shadow by doubt about what’s going to happen here. You may have
property and assets in Advocate that you may want to sell, develop or do a number of
9. Coastal protection in Nova Scotia has to date been dominated by “hard” solutions,
such as dykes, berms, and shoreline armoring (van Proosdij et al., 2013), but these
solutions are beginning to fail under SLR and storm surges (Grieve and Turnbull, 2013,
CBCL Limited, 2009). In line with growing global attention to ecosystem- and nature-
based alternatives to reinforcing hard infrastructure (Narayan et al., 2016, Cheong et al.,
2013, Harman et al., 2013), small-scale experiments in living shorelines and salt marsh
restoration have been underway locally. Setbacks or “managed retreat” remain
uncommon, in part due to local resistance, as described in Error! Reference source not
found. (Savard et al., 2016).
Box.1. Local resistance to coastal retreat
Local resistance to new forms of adaptation were apparent after the failure in a storm of a
natural cobble barrier that has protected a coastal lagoon called Big Lake from the
Atlantic Ocean for decades. Owners of a dozen small homes and cottages around the lake,
newly vulnerable to storm surges, have demanded that the natural barrier be rebuilt to
protect their homes. The Nova Scotia Department of Lands and Forests (NSLF) had fixed
a similar breach in 2010 but refused to do so again, instead recommending that residents
“fortify their properties with protective walls, put their homes on stilts and seek coastal-
flooding insurance”, referencing the municipality’s responsibility for having issued
building permits. While the cobble barrier was natural in origin, after being repaired it
became seen by residents as built infrastructure.
Over on the Bay of Fundy coast, hundreds of citizens of the small town of Hantsport
recently demanded that the province rebuild a privately owned causeway and aboiteau
(one-way drain used for land reclamation). The system, which had been in a state of
disrepair for many years, completely failed in December 2017, restoring the natural
hydrology to the system.
Sources: (CBC, 2018a; CBC, 2018b)
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things with. ... It’s going to be a long time before the government would actually move
anybody if that’s what has to happen.”
13. Advocate Harbour, Big Lake, and Hantsport (Box 1) all demonstrate citizen
preferences for government intervention using hard options to maintain the status quo
(Sherren, in press). This delays difficult decisions to retreat strategically in preparation
for what is to come. Yet compared with setback options, investments in hard
infrastructure are more expensive and retain negative consequences if those defences
were to fail. Moreover, investment in hard options encourages ongoing development in
high-risk areas, as expressed in the quote above, making setback options ever more
challenging. Such public sentiments represent—along with limited government budgets—
the biggest barrier to coastal adaptation in the region.
1.3. Truro case study: The North Onslow Marsh
14. Flood risk associated with SLR is a significant driver for action in the case study
of the North Onslow Marsh, in Truro, Nova Scotia. Truro is a small regional centre of 12
000 residents located on the floodplain of the Salmon River that flows into Cobequid Bay
(Bay of Fundy), and that floodplain is extensively dyked: first for agriculture but now
protecting residential, commercial and transportation infrastructure. Even without SLR
and storm surges, Truro experiences frequent and severe flooding from the co-occurrence
of rainwater accumulation, high tides and/or ice jams. The region has suffered at least
annual floods as far back as records have been kept (CBCL Limited, 2017). None of these
events seems to have dampened enthusiasm for floodplain development in the town,
meaning repeated exposures for “schools, senior homes and residences ... access roads,
commercial areas and industries” (CBCL Limited, 2017). In recent years, research on
emergency management has included Truro as a case study (O'Sullivan et al., 2013,
Grieve and Turnbull, 2013).
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Figure .1. Map of North Onslow Marsh Body
The North Onslow marsh body being modified (grey), with area to be restored (blue), aboiteaux to be
removed (black) and new/improved (white), old dyke (blue with dotted lines where to be breached), and new
dyke (black lines)..
Source: Raymond Jahncke, Will Flanagan, Saint Mary’s University Department of Geography and
Environmental Studies.
15. While Agricultural dykelands dominate the flood plain on which Truro is built,
the region is no longer dominated by agricultural employment. In 2016, natural resource
industries comprised only 2-4% of employment, dominated instead by retail, health care,
manufacturing and education sectors (Statistics Canada, 2017). This may be reflected in
increased repurposing or ‘fallowing’ of some dykelands.
16. Examinations of Truro’s persistent flooding problems and potential solutions
were carried out in 1971, 1983, 1988, 1997, and 2006, each inspired by significant flood
events. Consistent with the prevailing “command and control” (sensu Holling and Meffe,
1996) approach of the time, all of the resulting reports focused on “hard” solutions to the
problem. These included raising and strengthening dykes; constructing runoff storage
dams, a causeway/tidal dam to “cordon off” Cobequid Bay, or ice control berms; and,
approaches to improve drainage and reduce sedimentation such as viaducts, channel
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straightening and dredging (CBCL Limited, 2017). A significant challenge to addressing
this issue has always been the cost involved: Truro and the County of Colchester have
relatively healthy balance sheets but the province’s Financial Condition Index suggests
they both have inadequate capital reserves relative to the age of their assets, suggesting
they may not be able to afford to replace or improve them (NSDMA, 2017). The available
technology at the time of those earlier flood reports, however, made it impossible to
distinguish between the various causes of flooding. More recently, efforts to model the
river system in combination with the stormwater system has demonstrated the utility of a
holistic approach (El-Sharif and Hansen, 2001).
17. Tropical Storm Leslie in 2012 fuelled a severe September flood in Truro that
changed the local conversation (CBC, 2012). Until then, despite the history of flooding,
there had been little attention to it at the municipal level: there existed simply engineering
specifications for stormwater such as culvert sizing and new development regulations.
The provincial government was considered responsible for the integrity of the dykes on
which the region’s safety depended.
18. In that fall 2012 flood, a dyke on the North River breached in several places, and
politicians and affected citizens alike called for repairs and reinforcement to the dyke
system (i.e. building it higher) (Hand, 2012). The high school was evacuated and the
media shared stories of evacuated residents who live behind dykes, all apparently
unaware that the infrastructure was never designed to protect non-agricultural land uses
(Tutton, 2012 ). The breached dyke was privately owned and built but protected
numerous businesses, including an important local employer. The Province performed
repairs for emergency management purposes (Canadian Press, 2012), given more rain in
the forecast, but the responsibility for ongoing maintenance of this dyke was unclear. This
flood inspired the creation of a Joint Flood Advisory Committee for the County of
Colchester, Town of Truro, and Millbrook First Nation, including representation from
citizens and provincial government departments.
19. A $400,000 FRIIP-funded comprehensive flood risk study of Truro was
subsequently commissioned by the Joint Flood Advisory Committee. The consultants
developed a set of hydrodynamic computer models to understand the relative influences
of rainfall, river hydrology, tides, sedimentation and ice movements using detailed terrain
maps derived from Lidar, bathymetric surveys, field measurements and imagery from
multiple aerial platforms (Marvin and Wilson, 2016). Climate change projections were
explicitly modelled out to 2100. Once these dynamics were understood, which suggested
particular sensitivity of the system to rainfall volumes, several dozen flood mitigation
options and combinations were modelled. These options were ranked using stakeholder-
derived human, land use and infrastructure priorities (Table 1), as well as the protection
level that each provided (including in extreme events), its initial and life cycle cost, the
value of the land protected, and feasibility given environmental and permitting
requirements (CBCL Limited, 2017). Priorities were elicited from targeted stakeholders,
as well as at a public meeting with relatively low attendance according to several who
were there.
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Table 0.1. Stakeholder-derived priorities for the Truro Flood Risk Assessment
Rank
Human Health & Safety
Land Use
Infrastructure Services
1
Life
Hospital
Water supply/treatment
2
Emergency facilities
Residential properties
Communication
Power supply
3
Necessities of life
Livelihood
Senior Homes
Potable water
4
Protection of environment from
contamination
Schools
Roads
Wastewater
treatment
5
Access to an area
Industrial lane properties
Bridges
6
Social justice
Agricultural land
Dykes & aboiteaux
7
Regional access routes
Retail properties
8
Office uses
Recreational
facilities
Source: adapted from (CBCL Limited, 2017).
20. It is notable that despite the area’s strong farming culture, agricultural lands and
dykeland infrastructure ranked low (6) on both land use and infrastructure categories of
priority for flood protection. This is likely because agricultural dykes were designed to
allow some flooding; inundation of farmland every few years was expected and
considered low risk and perhaps even positive for sediment deposition. By contrast,
residential properties ranked high (2). The housing and infrastructure that was allowed to
be built in the flood plain has not been due to financial incentives such as increased
amenity, real estate value and thus increased taxes: the assessed value per square footage
of single residential units is unrelated to either proximity to water or elevation. Rather,
this at-risk development was a natural continuation of early development along shorefront
and riverfront roads, and the desire by the municipalities to capitalize on the economic
development opportunity of passing highway traffic.
21. The flooding problem in Truro is indeed complex: no single solution was found to
be effective through the 2017 analysis. In fact, no measure under CAD 100 million was
found to protect more than 20% of the priority areas, and most require costly earthworks
(e.g. river straightening, floodway bypass), maintenance (e.g. dredging) and/or the
continual spectre of infrastructure failure (dykes and aboiteaux). Raising dykes was only
modelled as effective at its most costly: when constructed as high as locally necessary (6
metres high in some areas, with commensurate design challenges given the footing width
of such a dyke), and when accompanied by specialized pumping (30% of priority areas
protected for CAD 300 million). Additional aboiteaux were considered in the 1970s to
hasten drainage, but after modelling found ineffective: while they may protect some areas
from storm surges, they hold in rainwater that usually accompanies such storms as well as
potentially increasing sedimentation. Modelling dyke breaches actually reduced flood risk
(CBCL Limited, 2017). Raising priority non-residential areas and roadways, and
purchasing homes for removal or relocation, protects the most priority area but costs
around CAD 200 million (as well as likely representing risks of civic conflict).
22. The analysis suggests above all that planning and regulatory processes should be
designed to avoid further floodplain development. In addition, stormwater infiltration
systems should be incorporated into new developments or when infrastructure is being
replaced (e.g. permeable surfaces, perforating stormwater pipes). This was modelled to
reduce flooding in priority areas by 30-40% at low cost.
23. The consultants also developed an infrastructure-based recommendation, ready to
submit for available funding opportunities. The preferred structural scenario was
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floodplain restoration, including realigning dykes to re-establish the floodplain and thus
its water storage capacity. While cost-effective and protecting 29% of priority areas,
combining widening dykes with the construction of pumps to pull water out from behind
dykes was expected to cost CAD 99 million. Alone, the dyke realignment part was only
modelled to reduce risk to priority areas by about 1%.
24. The full report was never publicised, though it is able to be found on the
Municipality of Truro website and media covered its presentation at a coastal and inland
flooding conference in 2015 (CBC, 2015). A similar flood risk study by CBCL of a
neighbouring jurisdiction had inspired the municipal council to seek to rezone a
residential area as a high-risk flood zone to halt further development in the face of climate
change. Citizens protested because of the possible detriment of real estate values to the
dozens of homes there (CBC, 2016). No municipality wanted to expose themselves to
similar controversy.
1.4. Policy context for management of sea level rise in Nova Scotia
25. The transitional space from ocean to land is a crowded jurisdictional space, so this
section covers only the context necessary for understanding this case: climate, coasts,
dykelands, floods and wetlands.
1.4.1. Climate adaptation
26. Canada’s approach to climate adaptation varies across scales and provincial
jurisdictions, and within jurisdictions between government portfolios (e.g. fishing,
tourism, energy, infrastructure, transportation), as well as outside to the private sector. An
example of inter-jurisdictional collaboration was the Atlantic Climate Adaptation
Solutions Project, a 2009-2012 partnership between Canada’s four Atlantic Provinces and
the Climate Change Impacts and Adaptation Division of Natural Resources Canada
(NRCan) that funded CAD 8.1 million of research on climate adaptation in the region
(https://atlanticadaptation.ca/). NRCan continues to provide leadership in this space
federally, offering funding and instigating science reviews.
27. Provincially, the Environmental Goals and Sustainable Prosperity Act in 2007
laid the foundation for climate action with incitement to a range of climate mitigation,
adaptation and education activities, including ambitious renewable energy targets (e.g.
25% by 2015, achieved; and 40% by 2020). A Climate Action Plan followed in 2009,
committing to create a Climate Change Directorate (now Unit) within Nova Scotia
Department of Environment (NSDE) to “work with provincial departments and
municipalities, agencies, schools, and hospitals to reduce GHG emissions and ensure that
effective adaptation measures are being implemented” (NSDE, 2009). This is a largely
enabling and educating role, rather than a regulatory one. Nonetheless, Nova Scotia
mandated the creation of Municipal Climate Change Action Plans (MCCAPs) by 2014,
making it the first province in Canada to require local level climate action plans.
1.4.2. Coastal protection
28. All activities in the exclusive economic zone (i.e., 200 nautical miles from mean
low tide mark) fall under Federal jurisdiction. For example, the Department of Fisheries
and Oceans (DFO) is the central federal agency to manage offshore activities, while
Environment and Climate Change Canada (ECCC) protects water resources from
pollution. Above that mean low tide mark the province dominates. The Nova Scotia
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Department of Lands and Forests (NSLF) is an important provincial agency for coastal
protection decision making with a jurisdiction that includes: beaches, crown lands and
provincial parks, trails on lands and over watercourses. NSLF also holds responsibility
for protecting and conserving endangered species and conserving wildlife and their
habitats, except for fish species that are controlled by DFO (DFO, 2009). NSDA controls
dykelands (see next section).
29. “Nova Scotia has at least 45 pieces of international, federal, provincial, and
municipal legislation that deal with its coastal resources” (CBCL Limited, 2009). Yet
critical pieces of legislation are missing, such as to guide coastal protection in the
province (Grady, 2018). Decisions in some contexts to abandon or retreat some of the
hard infrastructure at the coast in the face of SLR have been hindered by the perceived
political costs. Private land owners control most coastlines and have certain roles and
responsibilities in risk management decision making and implementation, but as has
already been seen the weak regulatory context creates ambiguity.
Dykelands
30. The NSDA is responsible for developing and managing dykes and dykelands
under the Agricultural Marshland Conservation Act, 2000 (Robinson et al., 2005). The
Minister of Agriculture can decide on developing, maintaining, improving and protecting
dykes, dykelands and agricultural marshlands, subject to the approval of the Governor in
Council. The Governor in Council can appoint an Agricultural Marshland Conservation
Commission to advise the Minister of Agriculture about dyke, dykeland and marshland
protection and maintenance. This Commission also hears appeals related to this act and
approves by-laws made by the Marsh Body. The Minister of Agriculture can also appoint
a Marshland Administrator who is responsible for performing administrative duties
imposed by the Act. Proposed changes to dykelands must also be cleared with Mi’kmaq
First Nations and the Nova Scotia Department of Communities, Culture and Heritage,
which is responsible for archaeological resources – including Acadian dykelands
themselves as well as other resources found in areas protected by dykes – via the Special
Places Protection Act (1989) (NSDE, 2005).
31. Individual landowners play a significant role in the governance of dykelands. A
Marsh Body is a collective of marshland owners who petition the Marshland
Conservation Commission to be incorporated (almost like a small municipality) for a
marshland section (an area of marshland that may be effectively dealt with as a unit in the
construction and maintenance of works– the Agricultural Marshland Conservation Act,
2000). This body can acquire, sell and lease personal property, and can decide on
constructing and repairing dykes at its own expense or in an agreement with the Minister
of Agriculture. This body also makes by-laws, which are subjected to the approval of the
Commission.
32. A Marsh Body needs to have an executive committee to perform the
administrative activities of the Body, and assess and value marsh and dykelands. Notably,
the chair and secretary of the committee are endowed with the authority equal to the
mayor and treasurer of a town to decide on any activity (e.g., dyke restoration, drainage
maintenance). The executive committee is supervised by the Governor in Council, who
can suspend the authority of the committee, should the committee cause any permanent
injury to the marsh and dykelands. The Governor in Council can, therefore, revert the
activities and authority of the committee to the Marshland Conservation Commission.
Moreover, the Agricultural Marshland Conservation Commission performs the Marsh
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Body’s roles and responsibilities in the absence of an active Marsh Body (Office of the
Legislative Counsel, 2000).
Wetlands
33. NSDE has jurisdiction over identifying and protecting salt marshes as wetlands of
special significance (Environment Act), and reversing historic wetland loss in the
province with restoration (Wetland Conservation Policy). Part of the no-net-loss
provincial Wetland Conservation Policy (2011) is the requirement that construction work
that destroys wetland must be compensated, usually like with like (Austen and Hanson,
2007). A typical offset depends on the type and quality of wetland lost and gained. For
instance, fresh water compensation requires a 2:1 ratio, two hectares created or restored
for every one lost, but it would likely be 4:1 for salt marsh replaced by fresh, or 1:1 for
fresh replaced by salt. The most desirable compensation projects are salt marshes, as well
as wetlands in parks or drinking water catchments, and restoration is more desirable than
creation (as the latter often fails). These differences are due to the extent of coastal
wetland or salt marsh losses in Nova Scotia, estimated at 85% on the Bay of Fundy
(Hanson and Calkins, 1996).
34. NSTIR has many such “compensation” transactions because of its road
construction and infrastructure maintenance. Many such maintenance projects in the face
of SLR involves raising infrastructure, which means going not only up but also “out” to
ensure stability, resulting in bigger project footprints. This only exacerbates the “coastal
squeeze” underway on foreshore habitats because of coastal infrastructure (Pontee, 2013).
NSLF is also interested in wetlands for the habitat functions they provide for waterfowl
and migratory birds such as sandpipers, for instance via the Eastern Habitat Joint Venture
of the North American Waterfowl Management Plan.
Flood risk management
35. Although the Federal government no longer holds direct dyke and dykeland
management responsibilities, it has played an important role in flood risk management. In
1975, the Federal government initiated the Flood Damage Reduction Program (FDRP) in
collaboration with all provincial and territorial governments (ECCC, 2013). The central
objective of this program was to identify and designate flood risk areas and to encourage
the provincial governments not to build, approve or finance any new development in the
designated zones. These agreements also aimed to discourage the provincial governments
from intervening via “cost-ineffective” structural measures (e.g., dykes, dams) if
preventive and non-structural options were available, like mapping or zoning, or if these
structural measures were found to be cost-effective and supportive for non-structural
measures. In addition, flood damage compensation has been strongly discouraged for any
new development in the designated zones (ECCC, 2013).
36. Truro was one of the high-risk areas identified by the FDRP, but the town was
informed after a 1988 study that they would only get one more damage payment after
which those would cease. The FDRP was wound down in 1999 (de Loë and
Wojtanowski, 2001). Other funds have filled the gap. Today, Public Safety Canada funds
a CAD 200 million National Disaster Mitigation Program (NDMP) (2015-2020),
including Disaster Financial Assistance Arrangements (DFAA), under a co-funding
agreement between the Federal and the Provincial governments. This fund is
administrated in Nova Scotia by the Emergency Management Office of the Department of
Municipal Affairs (NSDMA)), covering up to 50% of eligible provincial projects: flood
12 │
risk assessment, flood mapping, flood mitigation planning and investment in non-
structural and small-scale structural flood risk mitigation projects. NSDMA also
administers the federally funded New Building Canada Fund (also known as the Small
Communities Fund), for municipalities and villages with a population of less than 100
000 to develop disaster risk reduction infrastructures and utility infrastructures.
37. The Federal government has an alternative funding scheme for promoting climate
adaptation through influencing infrastructural development at the municipal level. The
Federal government launched the Gas Tax Fund in the 2005 Federal Budget as an ad hoc
funding mechanism for municipal infrastructural development, which was made
permanent in 2011 as a stable fund with an endowment of CAD 2 billion per year along
with a yearly increment of 2%. This fund is distributed on a per capita basis with a
minimum level of funding for least populated regions (0.75% of total fund), regulated
under joint agreements between the Federal and the provincial governments (Dupuis,
2016). Disaster mitigation is one of the eleven eligibility categories for Federal
infrastructural expenditure under this fund, including storm water and other utility
infrastructures (NSDMA, 2015a). In order to access these funds, the Federal government
mandated that Integrated Community Sustainability Plans (ICSP) be developed by each
municipality to guide the effective use of the funding (NSDMA, 2007), and Nova Scotia
additionally requires MCAAPs. Not all municipalities have the in-house capacity to carry
out such planning, so many of these plans were developed or facilitated by outsiders such
as consultants or academic teams (Warburton and MacKenzie-Carey, 2013).
38. Beyond the federal funds mentioned above the Nova Scotia Department of
Municipal Affairs (NSDMA) operates two other funding schemes for municipal
infrastructure (NSDMA, 2015b): FRIIP (mentioned earlier) is a Provincial government
initiative to fund inland flood water management infrastructure studies and development
programs (e.g., river training, floodway improvement, flood intensity mitigation,
floodwater contamination). The Provincial Capital Assistance Program to co-fund high
priority municipal infrastructure programs to reduce the cost burden for municipal
governments, including storm sewer systems. In general, however, the Government of
Nova Scotia is more concerned with freshwater flooding than coastal; no legislation,
policies or processes are yet in place to guide decisions around planning or retreat
options.
39. Municipalities along the coastline in Nova Scotia hold important roles,
responsibilities, power and authority in flood risk management given under the Municipal
Government Act, 1998. As directed in this act, every municipal government can develop
Municipal Planning Strategies (MPS) – a document that contains a detailed layout of
existing infrastructure and admissible future development along with other land use
practices (e.g., agriculture, recreation). The municipal governments can also enact land
use by-laws for the execution of that MPS. However, the municipalities are not required
to put these strategies in place: because of very different resourcing and in-house skills 40
out of 51 municipalities have developed comprehensive strategies, including Truro; the
other 11 municipalities have only single-issue coverage (GNS, 2018). The plans are
guided by the Statements of Provincial Interests (NSDMA, 2016). This statement is a
provincial government guideline managed by the Department of Municipal Affairs for
developing the MPSs and land use by-laws, covering five broad areas including: drinking
water, flood risk areas, agricultural land, infrastructure and housing.
40. The guidelines for flood risk areas are based on the erstwhile Nova Scotia-Canada
FDRP, which identified high flood areas (NSDMA, 2016). Infrastructural development is
│ 13
highly discouraged in these high-risk areas under this guideline, although the enforcement
of the guideline falls under the jurisdiction of the municipal governments (NSDMA,
1998). Since most of the coastal protection infrastructure (e.g., dykes, dams) and coastal
public land (e.g., beaches, wetlands, crown lands) managements are vested to the
provincial agencies, and agricultural marshland management is vested to the NSDA and
the Marsh Bodies, none of the guidelines directly address coastal flooding. That said,
several the MCAAPs in the Bay of Fundy do include coastal protection infrastructure
such as dykes and even go so far as to reference foreshore and fringe marsh size
requirements, so municipalities can wield considerable authority in coastal areas if they
so choose.
41. At present, coastal flooding is not an insurable hazard covered by most insurance
companies, but in May 2018, The Co-operators became the first insurance company to
cover coastal flooding and storm surge damages through their Comprehensive Water
Policy. Such products require good risk mapping, which is only now becoming available,
but an additional complication is that “flood-related losses are often directly attributable
to under-investment in public infrastructure, poor asset management, obsolete building
codes and ineffective land-use planning” (IBC, personal communication) as well as a lack
of functioning wetlands. As the Truro case study demonstrates, however, the line between
coastal and overland flooding is sometimes fuzzy. Even with flood mitigation by
homeowners and communities, insurance experts suggest the increasing expense of
insurance products, and dwindling support or capacity for taxpayers to subsidize
rebuilding when large-scale events occur, will require serious consideration of retreat
options and other nature-based options (Moudrak et al., 2018).
1.5. Dyke realignment and salt marsh restoration at North Onslow
42. The Onslow-North River Dyke Realignment and Tidal Wetland Restoration
project was a collaboration between government, community, academic and industry
partners. Initiated by the NSTIR in cooperation with the NSDA and NSE, the primary
purpose of the project was to create a “bank” of salt marsh “habitat credits” for offsetting
the loss or damage to wetlands arising from future NSTIR infrastructure projects. Being
part of the Bay of Fundy’s Minas Basin, tidal influence within the Salmon River that runs
past Truro, extends upriver beyond the North Onslow (NS067) project site. The position
of the site at the confluence of the Salmon River and North Rivers creates complex
patterns of water, sediment and ice movement, which result in high maintenance costs for
dyke and aboiteau infrastructure, the buildup of ice in winter, and an increased risk of
flooding. As such, the project was also intended to:
i. Reduce ongoing dyke maintenance costs for NSDA by reducing the total
length of dyke and number of aboiteaux;
ii. Enhance the protection of both public and private infrastructure, as well as
viable farmland; and
iii. Reduce flood risk and enhance resiliency for climate change through the
restoration of floodplain, one of several actions recommended by the 2017
Flood Risk Study (CBCL 2017).
No residential buildings would need to be relocated under this strategy, but some small
berms will need to be added to one property to ensure its protection. Access to some
electrical transmission infrastructure will need to be maintained as the former dykeland is
converted to foreshore marsh, as it would be too costly to move.
14 │
43. This cross-departmental project was nominated as a component of climate
adaptation training the Environmental Analyst of NSTIR was undertaking as an
‘adaptation champion’ with the Climate Change Unit of NSDE. The Unit had until 2014
worked with departments individually to help them identify climate risks, develop
adaptation projects, and ‘learn by doing’ some of the softer skills involved like planning
and communication. By the time this project was initiated, a few departments were being
trained together, which brought NSTIR, NSDA, and NSDMA around the same table. All
four departments subsequently had important roles to play in this project’s success.
1.5.1. Governance
44. CB Wetlands and Environmental Specialists (CBWES), in partnership with Saint
Mary’s University (SMU) and Queens University, was commissioned in December 2016
to develop a dyke realignment and restoration design plan for the ‘northern parcel’ of the
Onslow-North River Dykeland. The scope of work included working with NSDA and the
Marsh Body to determine the optimal location for new dykes and sourcing of construction
materials (e.g. ‘borrow pits’), identifying the location and size of breaches in the old
dyke, creating a restoration design for the tidal wetland, and anticipating habitat response
to restoration. This component was financed by NSTIR as part of the wetland
compensation process.
45. In Nova Scotia, any proposed activity that has the potential to alter the boundaries
of a marshland section for which the Marsh Body is incorporated requires consultation
with and agreement by two thirds majority vote of the Marsh Body, in accordance with
the Agricultural Marshland Conservation Act (2000, c.22, s.13b). The Marsh Body
engagement process expanded upon the consultation process as outlined in the Marshland
Act, engaging with the members of the Marsh Body and bordering landowners and
inviting them into the project design process. Consultation with Canadian National (CN)
Rail and Nova Scotia Power was also necessary due to the presence of rail and power
transmission infrastructure within the project site. Finally, an archaeological resource
assessment was required.
46. At project initiation, the site was a mix of forage (hay, grazed) and fallow
agricultural land. An aboiteau was in need of replacing, and reflecting on the Truro flood
study NSDA recognized the opportunity for realignment as well as reduced dyke
maintenance. The majority of the dykeland property needed for the project was purchased
by NSTIR in 2016 in anticipation of the project. However, several parcels adjoining the
floodplain had not been purchased. For these parcels flood vulnerability was assessed,
and mitigation actions would be recommended as part of the design. Despite its
agricultural origins, the site is complex for this kind of realignment: the Canadian
National (CN) rail line defines its eastern border, the 1763 Onslow Island Cemetery is
within its western boundary, and a power transmission line dissects the site. Consultation
with CN Rail and NS Power was necessary to address any potential risks to their
respective infrastructure either through the inclusion of flood protection measures or their
relocation, but while notified along with other landowners they were late to join the
planning table.
47. Following consultation with NSDA staff and additional analysis of the marshland,
which included site history, habitat conditions, and hydrology, several preliminary dyke
alignments were drafted as a proof of concept to guide early planning and consultation.
Various dyke realignment and tidal wetland restoration design options were tested using
Delft 3D hydrodynamic modelling software (including tidal, overland and river flows)
│ 15
and validated with the same field measurements of water levels and sediment transport as
available to CBCL for their flood risk study. All such validation work is hampered by
inadequate records, for instance a lack of long-term tide gauges near the site. The closest
permanent gauge operated by the Canadian Hydrographic Service is 200 km across the
Bay of Fundy, in Saint John, New Brunswick; all other available tide gauge records come
from short-term consulting or research projects.
1.5.2. Consultation
48. The intent was to collaboratively arrive at a realignment and restoration design
that was not just accepted but supported by the Marsh Body. This was to be achieved
through a series of community hall style meetings, a special topic meeting, and “kitchen
table” conversations with individual stakeholders. Prior to the initiation of this project,
however, the Onslow Marsh Body was not active and so the first step in the process was
to reactivate the group and provide them with the structure, information and tools needed
to effectively participate. At the first meeting, the idea and rationale for the project was
presented. The questions arising from the Marsh Body at this stage were about alternative
solutions to the flooding problems, which were difficult to debunk given the CBCL report
was not yet publicly available. A second challenge was difficulty interpreting the flood
modelling maps: when residents saw the modelled flood boundary under preliminary
scenarios, they struggled to understand how rarely the water would reach that level given
the hypertidal conditions of that site (Archer, 2013).
49. Over the period of meetings, the most contentious issue proved to be the issue of
mosquitoes. The concern was raised that the restoration to tidal wetland habitat would
lead to an increase in mosquito populations like what was experienced in Moncton
following the opening of the Petitcodiac tide gates (Gerwing et al., 2017). This was of
particular concern to a landowner who ran a nearby tourist attraction. To address this
issue, subject matter experts from the Petitcodiac region were invited to discuss the
process of monitoring for mosquito larva in their stormwater impoundments in fallow
dykelands, and applying larvicide as necessary to limit mosquito levels. In addition, a
zoology expert explained that once predator populations became established in the salt
marsh, they would eventually control mosquito populations, and effective drainage would
ensure balance was maintained.
50. The Marsh Body’s final meeting presented the proposed realignment design,
answered any remaining questions and conducted a vote in accordance with Marshland
Act to vary the boundaries of the dyke allowing the project to proceed. While adjacent
landowners could attend, only marshland owners could vote. Each landowner gets a
single vote, regardless of how much land they might own, and a two-thirds majority is
needed. The Marsh Body Chair reported that the landowners appreciated that they were
“sure giving us a lot of time to think about this.” The vote passed unanimously, with two
caveats: 1) that a pest-management protocol be developed as part of the project, including
monitoring, and 2) that ongoing communication with the Marsh Body be maintained.
1.5.3. Design
51. With the successful Marsh Body vote and a final alignment selected, the technical
specifications of the design could be finalized (Figure .1), which would mitigate concerns
of the creation of additional mosquito breeding habitat, create healthy salt marsh
ecosystems and hopefully reduce flood risk for Truro. The fundamental control on the
structure and function of tidal wetland habitat is flooding with salt water (Mitsch and
16 │
Gosselink, 1986, Neckles and Dionne., 2000). It is the hydroperiod (frequency and
duration of tidal flooding) of a wetland that determines the area of marsh directly
available as habitat, and thus useful as compensation credits. The first step of such design
is modelling the outright removal of the barrier, in this case the dyke, to see how the site
would naturally flood. This also allows for the identification of features, areas or
infrastructure that are likely to be at risk or negatively affected. Modifications to the
design and the incorporation of mitigation measures (i.e., new dykes, ditching, amending
land elevation) to alleviate these effects can then be explored and modelled.
52. For this project, it was determined that two new dykes would need to be
constructed landward of the existing structure– the primary dyke (1 km) along the
western end of the site to protect active marshland and the historic cemetery, and a small
dyke in the eastern corner of the site to protect infrastructure owned by CN Rail. In
addition, for effective flooding to occur, and to reduce standing water, which could serve
as mosquito breeding habitat, a channel network would need to be created and the old
dyke breached in several places. Dyke breach and channel widths were calculated using
hydraulic geometry (Graham, 2012, Williams and Orr, 2002), and channel locations
selected based on the channel network delineation and relict historic tidal channels
identified in historic aerials. Three of the four existing aboiteaux would be eliminated,
including the large three-barrel structure on McCurdy Brook, and a new aboiteau
constructed within the eastern dyke to ensure protection and drainage of low-lying lands
above the rail line. LiDAR DEM, topographic surveys, and several tide gauges deployed
by CBCL in 2014 and CBWES in 2017, helped the design of the hydraulic network for
the new marsh.
1.5.4. Implementation
53. The implementation of the above design is still underway. The archaeological
phase one assessment, conducted in accordance with the Nova Scotia Special Places
Protection Act under a Heritage Permit by a consulting firm, noted an artefact scatter at
the northern end of the proposed inner dyke footprint of a kind already recorded within
the Maritime Archaeological Resource Inventory. No additional significant
archaeological resources were identified in the area, however as mentioned earlier the
inner dyke was moved slightly to the east to avoid any potential damage to the 250-year-
old cemetery situated on an upland portion of the marshland.
54. Monitoring will be extensive, as this realignment represents an important
precedent. Although not yet provincially mandated, over the last 15 years, the NSTIR has
funded baseline (pre) and 5-year post-restoration monitoring at all its tidal wetland
restoration sites. CBWES is responsible for data collection and analysis of changes in
hydrological condition, vegetation, water quality, soils and sediments, marsh
morphology, nekton biology, and marsh surface elevation change. SMU will also track its
geomorphological change, for instance monitoring sediment accretion using drones, as
well as working to quantify the carbon sequestration potential represented by the restored
salt marsh. It is also estimated that within 8-10 years post-breach, the restored North
Onslow tidal wetland will be operating as a near optimum salt marsh habitat and
regulating (e.g. acting as a storm buffer) ecosystem services.
55. While a comprehensive cost benefit analysis (including in-direct ecosystem and
flood mitigation benefits) was not performed for this project, the direct costs accounting
currently available supports the North Onslow re-alignment as a cost-effective option. It
is estimated that the dyke-realignment will result in approximately CAD 520 000 of
│ 17
savings (Table 2). Additional benefits such as carbon sequestration and flood mitigation
will be empirically quantified as the project proceeds, and be used to inform future
decisions. The pre-alignment value of the land protected was CAD 400 000, excluding
utility (NS Power) and federal infrastructure (e.g. CN Rail).
Table 0.2. Direct costs of maintaining dyke in place (including ‘topping’ to predicted 2055
high-water levels) versus re-alignment of dyke infrastructure and tidal wetland restoration.
All figures in 2018 CAD
Maintain status –quo and top dyke in
place
Re-alignment of dyke infrastructure
Upgrade McCurdy’s
brook aboiteau
1 500 000
Land purchase (18
parcels, 92.5 Ha)
798 000
Top 3.5 km of dyke in
place
500 000
Archeology
71 559
Estimated 10 yr
standard
maintenance
180 000
Earthworks and breach
625 000
Feasibility, design &
baseline
161 000
TOTAL
2 180 000
TOTAL
1 655 559
1.6. Outcomes and lessons
56. This project remains under construction so its effectiveness in reducing flood
risks in Truro has yet to be tested. There are many uncertainties: the lag time involved in
the re-establishment of the tidal wetland and its ability to play an effective buffer role; the
impact of dyke realignment on sedimentation patterns and ice movement; and how such
changes will affect the dynamic hydraulic system in place. As with previous tidal wetland
restoration projects undertaken by CBWES (Bowron et al., 2012), a comprehensive 5-
year post-restoration monitoring program will help fill this gap in understanding. Despite
the inability to reflect directly upon the physical outcomes, it is possible to identify
several other outcomes and lessons for governance of this kind of social and landscape
change.
57. First, thanks to effective collaboration across scales of government, a lack of
climate change or coastal protection policy did not hamper action toward climate
adaptation in this case study. A number of pieces fell into place at the same time that
allowed this project to be put forward as a potential solution to many problems, and allow
multiple jurisdictions to work together. Marginal dykeland came up for sale at the same
time as the NSTIR needed wetland credits to offset their construction work. The size of
the projected salt marsh habitat restoration that would be involved (~93 ha) was
particularly attractive to the NSDE, with its responsibility over the no-net-loss Wetland
Policy. This allowed NSDE to offer to NSTIR half the normal offset ratio usually
required. This agreement with NSDE meant that NSTIR could make the case for
purchasing the dykeland at a price attractive to the landowner. The capital costs of the
dyke infrastructure protecting that increasingly marginal land were only likely to get
worse under climate change, and the department was already engaged in a prioritization
process for informing dykeland decisions such as maintenance, realignment or
abandonment. In this case, realignment would reduce the length of dyke to be maintained
from 3000 m to 1250 m. The non-NSTIR half of the cost of the project could be provided
by a 50/50 cost share between the NDMP and NSDA. Costs would be lower than what
could be expected in other regions due to the availability of reasonable modelling
18 │
evidence from the CBCL flood risk analysis indicating that widening the dykes would
contribute to some reduction of flood risk in Truro.
58. The above represents a positive outcome for wetland coverage, construction
offsets, dyke maintenance and landholder compensation. It is worth noting that this
collaboration came about in part because of constrained budgets.
59. Climate adaptation is notably absent from that list of clear wins. This is because
despite strong evidence of the utility of such approaches for flood and erosion protection,
as well as potentially climate mitigation through sequestration, it is not yet known
whether the restored marsh will prove adaptive to SLR in this complex setting. In the
absence of strong policy, it is difficult to credit any of the above positive outcomes to
government commitment around climate action. Yet, the NSDE Climate Change Unit was
a critical facilitator to this process in more ways than the wetland offset agreement
discussed above.
60. The NSDE Climate Change Unit has been working to change the culture in
government around climate issues for many years, including running courses for
government managers. As discussed earlier, this project emerged from one such NSDE
training, nominated by the climate change champion at NSTIR as his course project, with
key players from NSDA and NSDMA around the same table, facilitated by NSDA. Even
if the flood protection outcomes are uncertain, the value of the replicable process is not.
As such, climate goals underlie the whole undertaking, and if successful the project will
serve as an important precedent. It is an important start on this long-term project of
adaptation, and a relatively low-risk one, given that the project is already meeting so
many other goals.
61. This project is not, of course, a no-risk option. Changing any one thing in a
hydrologic system as dynamic as Truro’s, can lead to unexpected outcomes. The dyke
realignment design being used in this project has not been systematically modelled for its
impacts on flood or public safety upstream of the predicted extent of penetration of tidal
waters for 2100. For instance, it is possible that the change in hydrology resulting from
this project could exacerbate sedimentation issues in the main river channel, alter local
flood and drainage patterns, or adversely affect the behaviour of ice. Similarly, while an
option may have performed well in terms of the percent of overall priority areas where
flood risk was mitigated, people may still be at risk in specific places. There is some
indication from modelling of similar options by CBCL that a dyke realignment project
such as this one could shift some flood risk to other specific areas, such as low-income
housing sites upstream. This remains to be seen, but is an important consideration.
62. Given the tendency to prefer status quo landscapes, this project represents an
important opportunity to show Nova Scotia citizens what adaptation may look like, on the
land and in public process. The social achievements of this project could lead to larger
cultural change. This project created a Marsh Body organization where none was
previously active. It engaged that group in difficult conversations with a range of
government representatives and researchers. The proponents listened meaningfully and
made adaptations to their plan, including dyke placement and adding monitoring for
mosquitoes. The NSDE Adaptation Specialist noted that one thing somewhat lost by the
fact that climate adaptation was not yet a clear project win (though it was a goal), was the
fact that this is the first time affected residents in Nova Scotia voted for a managed
retreat: basially sacrificing land for ecosystem purposes.
│ 19
63. It is possible that this project set an important precedent: it was quickly followed
by a similar verdict about a managed realignment proposal on the Cornwallis River to the
west. Such outcomes with informed, engaged citizens are a significant departure from
recent headlines presented earlier about similar situations in Advocate Harbour, Hantsport
and Big Lake. Effecting ‘public good’ landscape changes of this type is a non-trivial
social challenge. However, the Marsh Body came together, reviewed the options, asked
questions and voted in favour of change. As NSDE carries out public consultation for
long-awaited coastal legislation, projects like this one provide important leverage as well
as a place for Nova Scotians to observe salt marsh restoration and the potential role it can
play in adaptation. The comprehensive monitoring framework established will contribute
to a growing database of pre and post empirical field data and visual representations of
the changing landscape.
64. It is argued by many involved in this process that the Bay of Fundy and its
erstwhile salt marsh ecosystem itself must be considered a stakeholder of such decisions.
The salt marsh ecosystem that is restored may represent a range of ecosystem services,
including fish nursery habitat, storm buffer, and carbon sequestration through so-called
‘blue carbon’. The multifunctionality of wetlands that allowed other policies to be used to
achieve this project. Ecosystem services may well be a useful way of exploring the costs
and benefits of other such nature-based adaptation options (ICF, 2018).
65. There is a desire by NSDA and other proponents of this project to carry out
similar projects elsewhere in Nova Scotia, including on the south side of the Salmon
River from the North Onslow project. That southern lobe of dykeland is closer to the
town centre, as well as being more actively farmed. Additional creative approaches may
be necessary where farmers are unwilling to sell land, such as the NSDA negotiating
trades of dykeland parcels rather than simply buying out active producers, as one of its
goals is to maintain agriculture where viable. The expansion of the dyke realignment
strategy may struggle in the absence of a strong provincial strategy and leadership on
coasts and climate. Nonetheless, this project represents an important learning experience
as well as precedent: an exemplar of the value of a genuine and patient consultation
process.
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