Climate-Ready Upgrades to the Town of Faro’s Water, Sewer, Storm, and Road Infrastructure

In 2019, Yukon Government – Community Services (YG-CS) contracted WSP Canada Group Limited (WSP) to conduct a Climate Resilience Assessment (CRA) for the Town of Faro as part of upgrades to its water, sewer, storm water and road infrastructure. As a Northern Canadian community, Faro faces unique threats caused by climate change, including increases in temperature and precipitation, as well as permafrost thawing. The CRA helped the town identify potential climate risks and incorporate recommendations into the detailed design and construction phases, ensuring that infrastructure upgrades are designed to withstand future climate conditions.

The Town of Faro is situated in a remote part of central Yukon, approximately 400 kilometers northeast of Whitehorse. The town is accessible only through a single road crossing the Pelly River. Faro was home to one of the largest open-pit lead-zinc mines in the world, which supported a community of 3,000 residents and led to the development of water, sewer and road infrastructure. Faro’s population decreased to 400 following the mine’s closure in 2003, leaving an overabundance of older infrastructure that was costly to maintain and repair. This prompted the Yukon Government to develop a community master plan and design the required upgrades to the water, stormwater, sewer systems, and roads.

The Town of Faro’s proposed upgrades are spread over several years and into four phases. The CRA focused on the design stage of Phase 2 and Phase 3 with upgrades to watermains, water services, sanitary sewer mains, sanitary sewer services, storm sewer mains and culverts, utility access roads and public roads. The assessment followed the Climate Lens Guidance from Infrastructure Canada and used the Public Infrastructure Engineering Vulnerability Committee (PIEVC) Protocol. The CRA showed that storm sewer mains, culverts and watermains are most vulnerable to increasing precipitation, warmer temperatures, more heavy rainfall events, decreasing frost events, and permafrost thaw. The assessment identified high level resilience measures, such as additional testing to better understand permafrost zones, rerouting sewer mains away from areas with high potential for erosion and implementing erosion control measures and optimizing drainage.

This project acknowledges the longevity of infrastructure projects, their important role in providing essential community services, and the significance of building infrastructure with future changes in climate in mind.

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Understanding and Assessing Impacts

To assesses the vulnerability of the Town of Faro’s water, sewer, storm and road infrastructure, the WSP assessment team identified the following infrastructure and climate parameters: temperature (average annually and by season), precipitation (including summer precipitation, heavy precipitation, and snow), frost, and cumulative events. Trends of these climate parameters were studied using modelled data from the Pacific Climate Impacts Consortium (PCIC) downscaled models, provided through the Climate Atlas of Canada, and supplemented with a literature review. Downscaled models were derived from 12 CMIP5 global climate models. RCP8.5 was selected for this study to best represent exposure in the worst case, business as usual scenario. Estimates for future maximum daily precipitation were calculated using the IDF_CC tool developed at Western University. The climate change analysis looked at the 2040- and 2070-time horizons, based on information provided in the Town of Faro Infrastructure Master Plan — 20 years (2040s) for roads, culverts, and drainage ditches and 50 years (2070s) for underground infrastructure, based on standard service life of the infrastructure components.

Historical data was obtained from Environment Canada’s climate normal station data collected between 1981 and 2010 at the Faro Airport meteorological monitoring station and reviewed to develop an understanding of the climate over 30-year periods to understand average conditions and extreme events.

At the onset of the project, it was determined that there was insufficient capacity within the town to hold a workshop. Instead, questions were sent to operational staff to share reflections on previously experienced weather events and observations about the assessment. The assessment team felt comfortable taking this approach as many of the experts involved had previously conducted site visits and worked in Faro. Examples of feedback received include less snowfall in the Winter of 2018/2019 and no observed changes in freeze-thaw cycles. Overall, the feedback helped identify potential climate trends and identify areas for further investigation.

Results of the climate change projections when compared with modelled historical data showed a projected increase in mean annual temperature, more heavy and intense rainfall events, less frost events, and permafrost thaw, which increases the vulnerability of the town’s infrastructure to failure or loss of function. For example, as permafrost thaws, settlement could impact underground infrastructure that is designed to flow with gravity (like sanitary and storm sewers) and changes to the slope could cause sags and blockages. For water services, cracks and ruptures could occur and lead to water quality impacts. Similarly to permafrost thaw, heavy rain and changes to rainfall patterns could result in washout and erosion.

A unique feature for climate resilience assessments conducted in Northern Canada is the consideration of permafrost. After completing the assessment, further borehole testing was conducted in the town, revealing no presence of permafrost. These findings were fortunate as the absence of permafrost significantly reduced the vulnerability of the infrastructure systems to climate change. Nonetheless, other assessments in permafrost regions must not overlook these vulnerability factors.

Identifying Actions

As part of the funding application under the Investing in Canada Infrastructure Program (ICIP), Phases 2 and 3 each exceeded the $10 million threshold and thus required a Climate Lens Assessment, as stipulated by Infrastructure Canada. To complete the Climate Resilience Assessment (CRA) component of the Climate Lens, YG-CS commissioned WSP in 2019 to conduct a CRA for these phases using the Public Infrastructure Engineering Vulnerability Committee (PIEVC) Protocol, which is an approved methodology. The CRA used the steps laid out in the Protocol to define the potential vulnerabilities of the upgraded water, sewer, storm sewer, road infrastructure to the impacts of climate change.

In total, the PIEVC Protocol process assessed 48 climate/infrastructure interactions. The majority of identified risks were medium and a few low-risk interactions. The three interactions from highest to lowest risk included:

  1. Storm sewer mains and culvert capacity and increased heavy precipitation events;
  2. Storm sewer and sanitary sewer mains in permafrost areas interacting with increasing temperature, increasing precipitation, and decreasing frost events; and
  3. Watermain in permafrost areas interacting with increasing temperature, increasing precipitation and decreasing frost events.

Using the results of the CRA, the WSP assessment team developed a list of specific recommendations for the future design of Phase 2 and 3 of the upgrades. In total, 9 recommendations were included in the CRA report. Examples of the recommendations included:

  • Conduct additional borehole tests prior to project to confirm permafrost zones.
  • Reroute sewer mains away from areas with high potential for erosion.
  • Implement erosion control measures.
  • Optimize road drainage to reduce the impacts of additional frost action.
  • Ensure adequate horizontal and vertical trench separation between watermains and sanitary sewer mains.

Additionally, since the extent of permafrost degradation wasn’t determined with precision, the Town of Faro was encouraged to develop an emergency response plan to efficiently answer to potential additional failures of the water, sewer and storm water system. It was also recommended that the project periodically revisit the vulnerability, risks and control measures considered in this assessment as new information becomes available, including climate projections, changes to operating parameters, local conditions and design standard and guidelines updates.

Implementation

To inform the design of Phase 2, additional borehole testing was completed to confirm and better understand if and where permafrost exists in the town. The borehole analysis yielded a crucial finding for climate change vulnerability: no permafrost was detected. This outcome meant many of the recommendations, including the installation of superpipe, was no longer required and vulnerability to climate change was reduced.

During the CRA, the team employed the IDF_CC Tool to apply future climate projections to Intensity-Duration Frequency (IDF) curves. This data was used to complete stormwater modelling during the design of Phase 2, which helped address concerns over the potential inadequate capacity of storm sewer infrastructure (ditches, culverts, and storm sewer mains) to handle projected increases in heavy precipitation events. The climate adjusted IDF curves were used to determine the sizing of storm system capacity. By incorporating these projections, the design team was able to better anticipate and accommodate the potential impacts of climate change on stormwater management infrastructure.

To date, the design of Phase 2 is complete, and construction is underway. The design of Phase 3 will be completed in the future and the findings from the CRA will continue to influence the design.

Outcomes and Monitoring Progress

The Town of Faro’s Phase 2 infrastructure upgrades project successfully met its initial objectives, with many of the climate resilience measures seamlessly integrated into the design and construction phase.

The results of the CCVRA provided valuable insights into how climate change may affect each type of infrastructure associated with the Phase 2 upgrades. It is anticipated that the results of the CCVRA will also help inform the design of the Phase 3 upgrades.

A significant advantage of the project’s approach was the ongoing involvement of the same team members from the climate resilience assessment through to the design and construction stages. This continuity ensured that recommendations were consistently revisited and implemented where necessary. Interviews emphasized the collaboration between the Government of Yukon and WSP, underscoring how this joint effort assisted a small town with limited capacity in becoming more climate resilient. The Government of Yukon provided comprehensive support throughout the initiative, including assistance in securing funding, managing contracts, and overseeing project management.

Despite these successes, the project experienced several challenges. For instance, the design of Phase 2 took longer than expected, as scope was added. The assumed length of time to complete construction was also underestimated. While originally set for 2021/2022, Phase 2 construction remains underway (2024).

Additionally, like many small towns in the north, Faro’s aging infrastructure needs upgrades that are costly, yet will benefit the community. Funding opportunities, like the Green Infrastructure Stream (GIS) of the Investing in Canada infrastructure plan has helped to bridge this challenge.

While there are many potential climate impacts across the Yukon, the investments made in the Town of Faro’s water, sewer, storm, and road Infrastructure upgrades to consider future climate change represents an important step towards enabling access to services that support a healthy community.

Next Steps

The project is set to complete construction of Phase 2 in 2024. The design of Phase 3 will begin once construction of Phase 2 is complete. Phase 4 is pending approval. The climate data may be reassessed to ensure the best up to date data informs the project going forward. For each Phase of the project, the project team will incorporate the adaptation recommendations into the design before they present it to the town.

Resources

Link to Full Case Study

Additional Resources:

Using climate change projections enables better adaptation decisions, as it allows you to better understand how the climate may change. To learn how to choose, access, and understand climate data, visit ClimateData.ca’s Learning Zone.