City of Calgary's Marda Loop Streetscape Project

In 2022, the City of Calgary contracted Dillon Consulting Ltd. (Dillon Consulting) to conduct a Climate Risk and Resilience Assessment (CRRA) for the Marda Loop Main Streets project (The Project). The Project refers to the design, construction, operation, and maintenance of updates to the Marda Loop Main Streets, 33rd Avenue and 34th Avenue from Crowchild Trail to 14th Street SW. It includes changes to the water, stoplight, and road infrastructure in the area. The vision for The Project is to create well-designed, quality public realm elements and public spaces that prioritize the pedestrian experience, and support ongoing redevelopment and a thriving economic environment. Once complete, it will offer Calgarians improved safety and accessibility, and new community gathering spaces and will embody Marda Loop’s unique character.

In Marda Loop, changing demographics and efforts of the Business Improvement Area (BIA) have created a resurgence of residential and commercial development in the area, calling for new retail opportunities and development expansion. Marda Loop is known as a trendy destination that offers a vibrant retail and commercial environment and a diversity of options to live and work in the community, attracting young families, business professionals and university students. This has made the area one of the most popular neighbourhoods in Calgary.

Calgary’s climate is expected to change in the coming decades, and these changes may potentially impact the City of Calgary’s assets, infrastructure, services, and maintenance programs – including public buildings and spaces, transportation networks, and City utilities. Changes to the climate will directly impact how people use the proposed project space in Marda Loop.

To better understand and improve the climate resilience of The Project, The City retained Dillon Consulting to complete a CRRA. The assessment identified potential risks from a changing climate and recommended and prioritized adaptation measures that could mitigate these risks. Identified design features that address climate adaptation considerations include a refreshed urban tree canopy to provide shade, installing public drinking water fountains, and replacing impervious concrete with pervious pavers to manage groundwater and runoff. These measures address potential risks to the construction phase of the Project, the built infrastructure, the natural environment, human well-being, and third-party infrastructure associated with projected increases in extreme heat events, warmer temperatures, wildfires, heavy rainfall, and more. The Project is one of the first projects in The City to implement recommended adaptation measures from the CRRA into the detailed design and construction phases of a project.

Understanding and Assessing Impacts

To better understand how Calgary’s climate may change in the future, The City partnered with the Calgary Airport Authority, Pacific Climate Impacts Consortium (PCIC) climate experts, and GHD (an engineering consultancy with climate experts) to develop climate projections that could be used for risk assessments as well as adaptation planning and other engineering projects. Details on the climate projections are summarized in the Climate Projections for Calgary Report, available online.

Historical weather data was sourced from the Environment and Climate Change Canada (ECCC) station at the Calgary International Airport (which began monitoring in 1953), with quality assurance/quality control conducted by The City of Calgary from 1960-2014. Observed precipitation, air temperature, wind speed and direction, relative humidity, and solar radiation data was collected from the airport. The historical data was then perturbed to the climates of the 2050s and 2080s. The climate projections utilized the Canadian climate normals period (1981- 2010) as the Global Climate Model (GCM) baseline period. The 2050s climate was based on the GCM projections for 2041 to 2070 (mid-century), and the 2080s climate was based on the GCM projections for 2071 to 2100 (end of century). Additionally, the climate projections utilize the ensemble of the CMIP5 global climate models for the RCP8.5 emissions scenario.

PCIC downscaled the daily air temperature and precipitation data using a statistical downscaling methodology (e.g., the Bias Corrected Constructed Analog with Quantile mapping, version 2 [BCCAQv2]) to a grid of approximately 6 by 10 km. The PCIC data include 27 GCMs, and three GCMs have two runs each, for a total of 30 data sets at this grid size. The grid size was selected based on the availability of gridded historical climate observations. The wind, solar radiation, and relative humidity data were dynamically downscaled with Regional Climate Models (RCMs) to a grid approximately 15 by 25 km through the North America Coordinate Regional Downscaling Experiment (NA-CORDEX). The grid size was selected based on the availability and resolution of RCMs. Data for up to 16 GCM pairs is available through this data source. The available high-resolution datasets are currently the highest-resolution data available and provide a clear climate change signal for Calgary within the level of certainty available in current climate modelling. Climate models use approximations to describe the complexity of the climate system while not being able to precisely define phenomena at a scale smaller than their grid cell.

For The Project, The City of Calgary utilized The City’s climate projections to determine climate likelihood scores, in combination with assessing historical weather impacts to determine consequence scores to assess climate risk to the project. The climate hazards of interest that could affect The Project include: extreme heat, increasing air temperatures, wildfires, drought, short duration high-intensity rainfall, severe storms, high winds, heavy snowfall and river flooding.
These changes could impact the infrastructure (built and natural), users of Marda Loop and operations and maintenance of The Project.

Identifying Actions

Increased trends in the magnitude and frequency of climate hazards prompted The City to develop a Public Infrastructure Climate Risk Assessment process that aligns with the Public Infrastructure Engineering Vulnerability Committee (PIEVC) Protocol and Infrastructure Canada’s Climate Lens requirements. The City’s Risk Assessment process includes specific criteria that outline when a CRRA must be undertaken by City projects, accounting for factors such as the infrastructure’s lifespan, value, and ability to reduce climate risk. These criteria, along with the City’s Sustainable Building Policy and federal funding applications (e.g., Infrastructure Canada’s Disaster Mitigation Adaptation Fund), serve as drivers to undertake CRRAs. A CRRA aims to identify a series of recommendations that could be integrated into the design stages of a new infrastructure or retrofit project to reduce climate risks to infrastructure and users.

Using The City’s CRRA process, climate data and pre-determined (already calculated and provided by The City) likelihood scores, Dillon Consulting engaged with City staff and members of the design team in three virtual workshops in March and April 2022 to complete the following:

  1. Impacts assessment (1st workshop) – Workshop participants evaluated how past and projected climate hazards have and may impact assets, operations, maintenance and users for The Project based on previous experiences in the area and potential future impacts.
  2. Consequence scoring and risk assessment (2nd workshop) – Qualitatively assessed the possible consequences of a climate hazard interacting with an asset. Workshop participants scored consequences using a consequence scoring system where “1” represents a very low consequence and “5” represents an extreme consequence. The likelihood and consequence scores were multiplied for each climate hazard-asset interaction to determine the level of risk across the three time periods (baseline, 2050s, and 2080s). High or extreme risks were identified and prioritized.
  3. Adaptation measures identification and prioritization (3rd workshop) – Workshop participants identified possible adaptation measures that could be applied to reduce the highest risks and prioritized the feasibility of implementation.

The CRRA examined risks to all users, built and natural infrastructure in The Project area throughout its life, including during construction. The CRRA used information from the South Calgary Community Climate Risk Profile and the Marda Loop Streetscape Master Plan for 33rd and 34th Avenues SW as context.

The CRRA assessed climate risks in the baseline (1981 to 2010), 2050s (2041 to 2070) and 2080s (2071-2100) periods. The results show the following potential risks by system category:

People (human wellbeing):

  • Extreme heat could affect construction workers through an increased risk of heat stroke and heat-related illnesses, leading to work disruptions.
  • Wildfires could cause smoke events that constrain safe work and worsen respiratory problems.
  • Extreme rainfall could cause work disruptions and create health risks for the public.

Built Infrastructure:

  • Extreme heat could damage sidewalks, road surfaces and other street infrastructure.
  • Increased air temperature could damage sidewalks, curbs, pathways and roads.
  • Drought could affect the soil underneath sidewalks and roads, potentially leading to movement and settlement.
  • Extreme rainfall could damage underground utilities from flooding.
  • Severe storms could cause high winds and impact the integrity of overhead power lines.
  • Heavy snowfall could cause snow accumulation that blocks drainage assets of the stormwater system.

Natural Environment:

  • Extreme heat could damage trees and reduce tree health, especially for new trees.
  • Increased air temperature could bring more invasive species or pests, leading to tree degradation.
  • Severe storms causing high winds and hailstorms could damage trees, lawns and flower beds.


After identifying and prioritizing the highest risks, the CRRA identified 26 measures to reduce risk and enhance resilience. From this list, Dillon Consulting performed a high-level assessment of economic feasibility, known as a Return-On-Investment Analysis (ROI). Using cost data from The City, an ROI provides information on whether the benefit from an adaptation measure exceeds the cost to implement and operate the measure. The measures with benefits that outweigh the costs can then be prioritized for implementation. The approach Dillon sought to apply in the Marda Loop Project follows the guidance in Infrastructure Canada’s Climate Lens General Guidance – Annex G – Return on Investment Guidelines. From the high-level ROI, the City selected five top adaptation measures for further consideration and implementation for the Marda Loop Main Streets project, of which four measures are expected to be constructed in 2024:

  1. Add water bottle refill stations to the Marda Loop Project (two will be constructed in 2024)
  2. Introduce drought-tolerant plants/landscaping elements (to be constructed in 2024)
  3. Replace impervious concrete with porous pavers (to be constructed in 2024)
  4. Allow for greater heat expansion joints in sidewalks and ramps; and
  5. Selection of low lateral tree species planted with structural soils/silva cells (to be constructed in 2024).

Construction on the Marda Loop Main Streets began in June 2023 and is expected to continue into 2024.
In 2023.

Outcomes and Monitoring Progress

The City of Calgary’s Marda Loop Main Streets Project experienced several challenges. The area is challenged with space constraints and utility conflicts. Due to increased labour and material costs, certain recommended adaptation measures were removed.

The project also experienced challenges in getting buy-in from the community and impacted parties for the following actions:

  1. The use of porous pavers in the City of Calgary is a pilot project. Challenges stemmed from operational concerns and maintenance techniques. The team worked with Stantec, the project design consultant and Road’s operations to understand what equipment and/or training is needed for upkeep and maintenance. There were also discussions surrounding asset ownership (stormwater, water, roads.).
  2. Coordination with a third-party utility extended construction in the area (for greater benefit to accommodate trees and desired soil volume) – a challenge featured in media stories because of the duration and intensity of construction.
  3. The project will build an all-access wheeling facility (MUP) that connects to Calgary’s Pathway and Bikeway Network (5A Program). The pathway will also provide an additional mode of transport in the area and connect to the Crowchild Trail Interchange, the future Richmond Green Park space and the Yellow Max BRT Station. The team has hosted multiple engagement sessions regarding the MUP, two online sessions targeting residents and businesses along the South side of 34th Avenue to inform them of the MUP and that public Right Of Way (ROW) is being utilized. Letters will be sent out to inform each site owner along the MUP in late fall in preparation for construction in the spring of 2024.
  4. The communications plan has key messages that describe the project and the goals and objectives of the project based on a hierarchy of priorities from public engagement.

Several steps were taken to help overcome these challenges, including:

  1. Multiple meetings with Business Units, Operations teams
  2. Creation of an Operations and Management Manual for the porous pavers
  3. Creation of monitoring process mobility
  4. Support for the contractor in installing a porous paver system
  5. Support for developers who are constructing and may affect the public urban realm
  6. Early communication and collaboration with business units

There are several lessons learned from this project, including:

  1. Use clear communication with asset owners on the project’s goals and objectives (including climate risk and resiliency). Provide additional review, documentation, technical or other information as requested.
  2. Conduct early and regular communication with business units. Problem-solve and conduct technical reviews as needed.
  3. Provide additional support as needed, during information sessions, individual meetings, or on-site meetings.

For this CRRA, an implementation plan was not prepared for this project. However, since this project has been completed, it is now expected practice that each project undergoing a CRRA complete an implementation plan.

Next Steps

The City will conduct frequent follow-up with project managers and engineers to monitor progress on the construction and implementation of design measures.