Chatham-Kent Lake Erie Shoreline Study

Climate Change has increased the exposure to coastal hazards in the Great Lakes. Co-development of long-term sustainable solutions with coastal communities is required to increase resilience. Given the magnitude of the risk and cost to protect coastal properties with traditional grey infrastructure (e.g., shore protection), in some locations the only viable option is large-scale transformative adaptation concepts that realign coastal land uses and create ecosystem benefits with habitat restoration.

This case study looks at the Chatham-Kent Lake Erie shoreline, which covers 120 km from Wheatley Harbour in the west to McPherson Road east of Clearville, plus Rondeau Bay. The Chatham-Kent Lake Erie Shoreline Study was part of a larger climate change adaptation project, co-funded by Natural Resources Canada’s Climate Change Adaptation Program, that integrated the latest information on historical and anticipated future impacts associated with climate change in four case studies.


Understanding and Assessing Impacts

Beginning in about 2013, Lake Erie water levels began a steady rise above the long-term average (LTA) lake level of 174.15 m, and as of July 2019, had risen almost one metre to 175.14 m, their highest levels ever recorded impacting both Bluff Trail and Talbot Trail. Increased lake levels have caused significant coastal erosion, bluff erosion, and coastal flooding in many locations along the 60 km stretch from Erieau to Leamington. Local roads and highways, and hundreds (if not thousands) of waterfront cottages, homes, estate homes, farms and tourist accommodations populate the waterfront, many of which are less than 2 m above the LTA lake levels.

Many factors were considered in the assessment phase. In addition to the rise of long-term average lake levels were land value and relocation costs, onshore winds and storm events, as well as ice shoves, that can magnify the impact of high water levels, and typical storm events and the seiche effect (from standing waves in enclosed bodies of water) that can elevate lake levels by more than 0.5m and accelerate erosion.

A first for the Canadian Great Lakes region, the Chatham-Kent Lake Erie Shoreline Study explores the influence of climate change on future coastal hazards due to changes in storms and ice cover and the associated challenges for the coastal communities of Chatham-Kent.

 

Lake Erie shoreline erosion and flooding hazards will present significant challenges to existing Chatham-Kent infrastructure and abutting landowners, and climate change is expected to make the hazards worse in the future.

Identifying Actions

Proactive adaptation investments, including retreat and nature-based approaches, tend to provide overall economic savings. Multiple sources, including the Global Commission on Adaptation and the Insurance Bureau of Canada, calculate that investments in community resilience have a return on investment of $2–$10 in future averted losses for every $1 spent proactively.

Concerns about a possible dyke breach in the winter of 2019–2020—which could have flooded hundreds of hectares of land north of Erieau—led to the emergency closure of the Talbot Trail, and homeowners were not allowed access to their homes for up to four weeks.

Additionally, the flat farmland immediately north of Point Pelee 26 National Park and east of Leamington is at risk of inundation and coastal erosion as lake levels rise. Flood protection dykes that currently prevent inundation of this area during high water events are in need of significant repair, as they do not presently meet minimum provincial standards. Dyke repair costs plus the additional cost to add height to the dykes currently protecting approximately 5,000 acres of farmland may be more than the land is worth, leading to the possibility that the planned retreat of hundreds of current rural residents may be inevitable if lake levels continue to rise.

The process used to identify the adaptation options, including retreat, for the 439 lakefront homes between Erieau and Leamington utilized a host of public engagement strategies. A dedicated website (“Let’s Talk Chatham-Kent”) was used for information-sharing, public engagement and feedback about climate change adaptation options. Nine public meetings over a seven-month period were also held with almost 1,000 participants to introduce the study, generate ideas about possible adaptation approaches, and solicit feedback on the various options identified by the consultants. Two roundtables were also held with municipal officials, conservation authority staff, and senior provincial and federal government officials.

Implementation

The process leading to the planned retreat cases has varied depending on the category of asset under consideration. Approximately 30 km of the Talbot trail was proactively realigned by the Municipality of Chatham-Kent at a cost of $200 000, while another portion of the Talbot trail has been closed due to erosion damage, and is still awaiting realignment. A proposal to realign the majority of the remainder of the Talbot trail is currently under consideration at the cost of an estimated $31-40 million. A recent assessment of the Trail suggests that up to 439 primary or secondary buildings will likely be affected by coastal erosion within 50 years or less, with a total assessed value of $59.7 million.

Planned retreat is actively being considered as a proactive climate change adaptation option for many of these properties. Of immediate concern on this stretch of Talbot Trail are homes along Erie Shore Drive near Erieau collectively assessed at a value of $20 million. A planned retreat program and cost benefit analysis has estimated the cost of buyouts at at least the assessed home value and is currently under consideration.

A standard transportation planning approach was used to reactively realign portions of Bluff Line and Talbot Trail (e.g. identify a preferred rerouting option, carry out environmental assessment studies, acquire land, and then realign the road). The process identified proactive planned retreat as an option for multiple portions of roadway stretching from Erieau and Leamington. Once the areas at risk were identified, a series of adaptation options were identified using the familiar PARA (protect, accomodate, retreat, avoid) framework, and a cost-benefit analysis was carried out for each option.

Towards Leamington, several planned retreat projects are already completed, and more are at the proposal phase. One 500 m portion of a bluff top road known as Bluff Line was realigned approximately 75 m inland due to nearby rapid bluff erosion of 1.4 m/year.

Outcomes and Monitoring Progress

While some actions to relocate infrastructure and buildings have been implemented to date, planned retreat is still being considered as an adaptation strategy for many portions of the Talbot and Bluff Trails, but many questions remain. How will the planned retreat of buildings deal with the issue of compensation (e.g. assessed value vs. market value)? Will an effort be made to support homeowners, farmers and building owners throughout all stages of the retreat process? To what extent will retreated lands need to be remediated before coastal erosion or coastal inundation consumes the land left behind?

The main lesson learned from this case is that reactive post-erosion retreat can be used constructively to trigger and signal the need for proactive climate change adaptation. Once several assets were threatened by erosion, the Chatham-Kent authorities commissioned future-oriented hazard assessment studies that allowed them to proactively identify planned retreat as a viable climate change adaptation option.

Next Steps

Once the most vulnerable areas are prioritized, planning and engineering studies will be required to implement the climate change adaptation approaches outlined in the study. Government and stakeholders must continue to work together to pursue viable funding models and implement solutions. Moving forward, Chatham-Kent and other coastal communities must focus on building resilience to coastal hazards with proactive planning and zoning, recognizing some locations are simply not suitable for coastal development. The most cost-effective adaptation strategy is ‘avoid’ and the path to more resilience will be embracing nature-based solutions, climate adaptations, and retreating from high-risk coastal areas.

Resources

Link to Full Case Study

Additional Resources

Further understand how climate information can be applied in decision-making by exploring the Transportation Module on ClimateData.ca