Protecting and Restoring PEI’s Coastline

Since the mid-2000s, protection and restoration of Prince Edward Island’s (PEI) coastal areas has been a high priority for the Government of PEI. As the climate continues to change, these types of projects have become increasingly important. In 2021, the Government of PEI developed expanded restoration plans for two coastal locations, West Point-Cedar Dunes Provincial Park, and Basin Head Provincial Park, both of which are experiencing ongoing and extensive impacts from sea level rise, storm surge, and wave-driven erosion. On opposite ends of PEI, these locations are important tourist destinations with unique beach-dune environments. Together, the two sites include a number of amenities such as a historic lighthouse (built in 1873), campground, hotel, museums, harbor, restaurant, and washroom facilities. These restoration projects build on an ongoing strategy to protect coastal roads, buildings and other infrastructure as well as the unique dune ecology. Identification and prioritization of restoration actions uses classification and sensitivity mapping of the shoreline along with updated coastal flood maps depicting PEI’s coastal floodplains for 2020, 2050, and 2100. The Departments of Environment, Energy and Climate Action, Fisheries, Tourism, Sport and Culture, and Department of Transportation and Infrastructure (DTI) work collaboratively to prioritize coastal protection and develop site-specific restoration projects. DTI also conducts extensive monitoring of previous shoreline restoration projects using drone technology and land-based surveys to allow for continuous evaluation and improvement to future design techniques. Construction of both the West Point-Cedar Dunes and Basin Head restoration projects began in the winter of 2021; work at Basin Head is complete and additional work will be done at West Point-Cedar Dunes during the winter of 2023-24.

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Understanding and assessing impacts

The impacts of climate change have been evident and well-documented along the coast of PEI for decades. Several major storms in the early 2000’s caused unprecedented flooding and erosion and spurred action by the Government of PEI to undertake a number of important coastal restoration projects to protect infrastructure and ecosystems. Recent hurricanes, including Dorian in 2018 and Fiona in 2022, have had devastating impacts to the coast, as well as inland areas. The 2021 Provincial Climate Change Risk Assessment identified coastal erosion as the greatest level of risk to PEI by 2050. It notes that, due to the Island’s socioeconomic and socio-cultural reliance on the coast, nearly all Islanders are likely to be directly or indirectly affected by coastal erosion in the future. Key consequences of unmitigated future coastal erosion include:

  • Potential for long-term or permanent damage to Island infrastructure, especially transportation, and wastewater infrastructure.
  • Economic impacts and widespread mental health impacts, particularly as result of loss of sense of place and increasing climate anxiety.
  • Risk to endangered, at-risk, and endemic species (e.g., piping plover, giant Irish moss) and unique natural environments (e.g., mobile parabolic sand dunes).
  • Impacts to the tourism and recreation industry, including narrowed beaches and restricted access to parks, historic landmarks, golf courses, and other resources.
  • Inundation or erosion of socio-cultural coastal communities and properties.

Identifying Actions

In 2011, the PEI Department of Environment, Energy and Forestry developed classification and sensitivity mapping for the entire PEI shoreline. By characterizing and classifying the shoreline, resource planners and managers can evaluate shoreline vulnerability and delineate coastal hazards, including coastal flooding, coastal erosion, and damage to coastal ecosystems. All of these hazards are influenced by the combined actions of sea level rise, tides, storm surge, reduced sea ice and wave action. This resulted in a map containing a wide range of information from shoreline type, characteristic meteorological and oceanographic conditions, and coastal structures. The information was used to compute littoral transport values and estimated vulnerability to coastal flooding and erosion. In 2021, PEI released a province-wide Climate Change Risk Assessment as well as updated coastal flood maps, depicting PEI’s coastal floodplains for 2020, 2050, and 2100. Using data that was acquired by the province through the National Disaster Mitigation Program and ClimateData.ca, the updated coastal flood maps will help government, municipalities, and the public make sound planning decisions for the future. The maps also inform Coastal Hazard Assessments available for coastal properties, as well as a new series of Watershed Flood Projections Reports for developers and design professionals. Through these studies, as well as ongoing monitoring, severe winter storms, especially during ice-free winter periods, have been shown to result in heavy erosion at a number of coastal sites including: Panmure Island, Souris, West Point-Cedar Dunes, and the Basin Head inlet. In partnership with the Department of Environment, Energy and Climate Action and the Department of Fisheries, Tourism, Sport and Culture, the Department of Transportation and Infrastructure works collaboratively to prioritize coastal protection and restoration projects. Along with protecting critical infrastructure, the natural environment, recreation, and tourism are important considerations when designing site-specific restoration actions for PEI’s coast.

Implementation

Protection and restoration of our Provincial coastal environment has been ongoing in various priority locations since the mid-2000s, often with phased approaches. Below are various examples of restoration and adaptation projects that have been worked on since the early 2000s.

In 2012, a Langley Wall (timber crib / steel pile seawall) was constructed to protect the shoreline and vulnerable lighthouse at West Point-Cedar Dunes. Ongoing monitoring showed that the structure performed well but required occasional maintenance and reinforcement, which led to the realization that a larger adaptation project was needed. A project was launched to protect 1.5km of shoreline at the West Point-Cedar Dunes area with a series of nine inter-tidal reefs and a terminal groyne structure. Construction of five intertidal reefs and the terminal groyne were completed between 2021 and 2023. Construction of two additional reefs will take place throughout the winter of 2023 -2024.

Restoration of the Basin Head inlet took place throughout the winter of 2021-2022. At this location, storm surge impacts resulted in the location of the historic channel to shift dramatically to the east, to the toe area of a large sand dune system. Over time, the dune eroded into the estuary, causing shallowing of the estuary and infilling/choking of the Basin Head inlet that provides tidal passage between the ocean and the estuary.  This led to the need for regular dredging to ensure safety of the beach-goers and to protect the natural conditions in the upper estuary. The Basin Head inlet, a relatively shallow coastal lagoon designated as a national Marine Protected Area, supports an important ecosystem and a unique type of Irish moss that may only exist within the boundaries of Basin Head. Restoration work included the installation of two T-shaped directional stone groynes immediately upstream of the inlet area. These directional groynes had two primary purposes: they provided a foundation for the toe of the dune system, curtailing the ongoing erosion and sedimentation problem, and were positioned so that they re-established the historic channel location upstream of the inlet and maintained the preferred channel alignment over the long term.

In 2012, a Langley Wall was constructed to protect the Trans-Canada Highway at the Souris causeway. Dune restoration and shoreline stabilization works also took place to restore and strengthen the existing sand beach-dune system. In 2018, two intertidal reefs were constructed using local sandstone to dissipate wave energy, promote sand deposition, and enhance longer-term stabilization of the sand beach-dune system.

In 2006, 750m of shoreline was protected and reinstated at Panmure Island with a buried two-tier stone revetment structure covered with beach sand and native plants.

Outcomes and Monitoring Progress

The Department of Transportation and Infrastructure, often in partnership with the University of PEI, monitors the effectiveness of shoreline projects using drones, as well as standard land-based surveys.

Monitoring of intertidal reefs at Souris  has illustrated the  success of  implemented adaptation actions here. This positive outcome influenced support for the implementation of similar projects at West Point-Cedar Dunes and Basin Head. Undertaking these large projects with a staged approach has been very successful. Both the reefs at Souris and West Point-Cedar Dunes have functioned as intended. These sites can serve to demonstrate the effectiveness of such adaptation initiatives in protecting coastal areas.

At the West Point-Cedar Dunes location, the intertidal reefs and groyne installations have built up the shoreline with a natural beach in front of both the historic lighthouse and Provincial Park. The intertidal reefs and groynes were successful for holding the shoreline in place from significant coastal erosion during Hurricane Fiona.

At Basin Head, the two T-shaped directional groynes are working incredibly well. The channel is maintaining its position in the historic location, and, with the channel seemingly self-scouring, inlet water depths are being maintained at desirable depths. The previously eroding dune system has also stabilized and between the two groynes, beach sand is collecting, and a user-friendly sand beach area is being reestablished.

These very visible projects have been important in bringing awareness to the impacts of climate change and effective adaptation solutions not only to the community, but also to decision makers within governments.

Next Steps

Each site is very different, and solutions must be site-specific. As pioneers in coastal engineering, the Government of PEI will continue to monitor and learn project-by-project, incorporating lessons learned. To date, the majority of assets have been protected without undertaking relocation efforts.  Construction of additional intertidal reef projects are being considered for other locations pending funding approval. As climate change continues to impact weather patterns and coastal environments, the Government of PEI will continue to be innovators in solutions to protect and restore coastal environments now and into the future.

Resources

Link to Full Case Study

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