CSA S503: Community Drainage Planning, Design, And Maintenance In Northern Communities

In 2020, the Canadian Standards Association (CSA) published the second edition of CSA S503: Community Drainage Planning, Design, And Maintenance In Northern Communities, to address existing and anticipated community drainage management challenges arising from the need to adapt to future changes in climate. Community drainage systems in Canada’s North are different than systems in most other regions of Canada because of, among other factors, the unique climate, geology, and geography of the North. This region has long periods of extremely low temperatures; underlain by permafrost and other ground-related engineering challenges. The North is also a region of small, isolated communities with low population density and a large indigenous population that are difficult to reach and service. Different communities have different needs and, in Canada’s North, the need to address the challenges of climate change could not be clearer. Flooding brought on by climate-fueled extreme weather can impose heavy costs on small communities. Community leaders and insurers are looking for ways to protect vulnerable infrastructure and make their communities safer and more resilient in the face of battering storms. This Standard has been developed in compliance with the Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. CSA Group received funding for the development of this Standard from the Standards Council of Canada, as part of the Northern Infrastructure Standardization Initiative with input from the Northern Advisory Committee (NAC).

Read the Summary Link to Full Case Study

Understanding and Assessing Impacts

Climate change in Northern Canada is occurring faster than expected, resulting in increasingly frequent and unpredictable extreme weather events. While the winters are long and cold, the short warm summers and brief shoulder seasons of spring and fall create perpetual surface drainage issues that are catastrophic in the extreme case, and a constant challenge every year. These challenges are compounded by the limited climate data available, adding to the risk and uncertainty. Many professionals agree that the changing climate has, and will continue to, alter northern weather conditions. Observed impacts in the North include:

  • an increase in the frequency of extreme weather events resulting in greater snow accumulation, winter rain, icing, and higher winds;
  • rapid spring melting;
  • more sudden, intense precipitation events; and
  • greater weather instability in general.

The results of vulnerability assessment studies undertaken in the North so far have confirmed that existing drainage and infrastructure are often inadequate to accommodate the effects of a changing climate. In many instances, there is a need for professional engineering guidance on how to manage drainage in a coordinated manner. A lack of coordinated planning, and not having the necessary equipment and supplies on hand when they are needed, ultimately results in delayed and more expensive repairs in the future. Other conditions often associated with climate change, such as warming and degrading permafrost conditions and pronounced local shifts in hydrogeology, are creating new drainage problems within communities and making existing problems worse. Consistent and regular annual maintenance is expected. However, regular maintenance alone is not sufficient to address the risks, challenges, and impacts of unpredictable catastrophic events where immediate response is required and repair capabilities are limited. New tools and adaptation strategies are needed to manage the effects of climate change on community surface drainage systems.

For additional climate information, look at the Resources section of this example (below). 

Identifying Actions

This standard was developed by the Working Group on Community Drainage System Planning, Design and Maintenance under the jurisdiction of the Technical Committee on Northern Water, Wastewater and Stormwater and the Strategic Steering Committee on Natural Resources, and has been formally approved by the Technical Committee. It specifies the minimum planning, design, and maintenance requirements for community drainage systems in Canada’s northern communities. The main objective is to increase the capacity of communities and individuals to prepare and implement effective community drainage plans. These plans address both existing and anticipated drainage management challenges arising from deficiencies in past practices, as well as the need to adapt to future changes in climate. It provides guidance to practitioners who are involved in the planning, design, construction, rehabilitation, and maintenance of drainage systems in northern communities. The provisions of this Standard are derived from existing best practices and may be incorporated directly into community land use plans. Additionally, this Standard is intended to:

  • specify techniques to plan for and implement community drainage systems to account for the effects of a changing climate and permafrost regime;
  • describe practices for site and community planning that help to maintain the service life of community infrastructure, as well as the natural landscape processes through avoidance, mitigation, and drainage system management practices;
  • provide low-cost, practical solutions that can be adapted and implemented given local constraints on capacity and resources;
  • help northern communities protect community assets; and
  • promote public health and safety in northern communities.

Implementation

Currently, the standard is being utilized to tackle drainage planning in multiple communities across Nunavut. Formal master drainage plans have been completed in the following communities with the support of the mentioned partners:

  • Geotechnical and Drainage Analysis, Clyde River, NU (2020). Stantec Nunami Limited.
  • Hamlet of Kugluktuk Master Drainage Plan (2019). Tetra Tech Canada Inc.
  • Hamlet of Hall Beach Master Drainage Plan and Geotechnical investigation (2020). Tetra Tech Canada Inc.
  • Hamlet of Igloolik Master Drainage Plan and Geotechnical Investigation (2020). Tetra Tech Canada Inc.
  • Hamlet of Kimmirut Master Drainage Plan (2020). Tetra Tech Canada Inc.
  • Hamlet of Pond Inlet Master Drainage Plan and Geotechnical Investigation (2020). Tetra Tech Canada Inc.
  • Geotechnical Investigation and Drainage Planning Services in Sanikiluaq, NU (2020). EXP.
  • Hamlet of Cape Dorset Master Drainage Plan (2020). Tetra Tech Canada Inc.
  • Geotechnical Evaluation and Drainage Planning in Rankin Inlet, Nunavut (2022). Stantec Nunami Limited.

These communities are now incorporating the results of geotechnical investigations into their drainage plans. Furthermore, municipal zoning by-laws are being amended based on the standard to remove vacant lots that have been deemed “not suitable for building” and re-classifying them as “open space” or “recreation zones”. Future subdivisions are being designed based on the drainage and geotechnical studies that have been completed (e.g. the northern expansion of Rankin Inlet, which is being planned as part of the new Community Plan by-law under development). All of this is a significant contribution to community climate change adaptation, as communities try to minimize impacts on subsurface permafrost and to, generally, make regions more habitable.

Outcomes and Monitoring Progress

Advancing climate-resilient drainage systems protects buildings and infrastructure from the costly impacts of flooding by improving the stability of underground permafrost and reducing the risk of sinking soil. The Standard specifies the minimum planning, design, and maintenance requirements for community drainage systems in northern communities. This includes the provisions for site-level and community-wide drainage system planning, development, and operations. The provisions apply to drainage systems used for the collection, conveyance, detention, and discharge of excess surface water in the form of overland flow, originating from precipitation, snowmelt, or ice melt. By following this standard, communities can improve their ability to manage their existing drainage challenges, address existing deficiencies, and prepare for future weather events. This Standard ensures that projects carried out by different suppliers at different sites – often separated by great distances – will all confer a similar level of resilience.

Next Steps

Geo-technical studies are currently ongoing in the following communities:

  • Geotechnical Evaluation and Drainage Planning in Arctic Bay, Nunavut. Stantec Nunami Limited.
  • Hamlet of Grise Fiord Master Drainage Plan. Tetra Tech Canada Inc.
  • Geotechnical Evaluation and Drainage Planning in Gjoa Haven, Nunavut. Tetra Tech Canada Inc.

Once these studies are complete, the Government of Nunavut will train municipalities to implement the standard in their drainage plans.

Resources

Link to Full Case Study

Additional Resources:

Additional Climate Information:

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. To further understand how climate information can be applied in community infrastructure related work explore the Buildings Module on ClimateData.ca.