Conservation planning

Knowledge, Perception and Application of the Mitigation Hierarchy Among Officials in Canadian Federal Regulatory and Resource Management Agencies

Poulton, D. and Ray, J.

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Key points

• Mitigation hierarchy is an ordered approach to environmental impact assessment:
  1. avoid impacts first;
  2. minimize impacts that can't be avoided;
  3. restore onsite where possible;
  4. rely on offsetting or environmental compensation only as a last resort.
• Previous case studies have noted that regulators and proponents tend to move too quickly to offsetting as the preferred form of mitigation
• This study examines whether Canadian federal regulatory and resource management agencies tend to disregard mitigation hierarchy, and makes recommendations to improve its application.

Abstract

In the face of a steep decline in biodiversity there is an urgent need to develop new policy tools and improve the application of existing tools, including the assessment and mitigation of environmental impacts at the project level. As impact assessment has evolved as a profession and discipline impact assessment has developed frameworks and doctrines. Among those frameworks is the mitigation hierarchy. This prescribes that that one should avoid impacts first and foremost, then minimize those impacts not avoidable, then restore onsite where possible, and finally rely on offsetting or environmental compensation only as a last resort. It is a dictate that is found in policies, academic literature and professional guidance around the world, and in Canada.

The rationale of the mitigation hierarchy is that intact functional ecosystems, those left undisturbed by avoidance and minimization measures, are more mature, complex and resilient than those created or restored by artificial means, the kind which form the basis for onsite restoration and offsetting. The practical challenges of offsetting in particular are well-documented. Despite the widespread acceptance of the mitigation hierarchy, three previous case studies examining the United States, Australia and the Province of Alberta have noted a tendency on the part of both regulators and proponents to move too quickly to offsetting as the preferred form of mitigation, thereby contradicting the hierarchy by effectively skipping several key stages. Some have suggested that this disregard of the hierarchy in practice is widespread. This may forego opportunities to optimize environmental outcomes by overlooking avoidance and minimization options.

The purpose of this study was to examine whether that suspicion that the mitigation hierarchy is often disregarded was valid with respect to Canadian federal regulatory and resource management agencies. The qualitative method used to do this combined a review of legislation and policies, and of impact assessment processes, with 36 interviews with officials in eight different federal agencies and stakeholders with experience in dealing with those agencies. This was intended to explore experiences, perceptions and ideas among the interview participants.

Recommended citation

Poulton, D. and Ray, J. (2023). Knowledge, Perception and Application of the Mitigation Hierarchy Among Officials in Canadian Federal Regulatory and Resource Management Agencies. WCS Canada. https://www.canada.ca/content/dam/iaac-acei/documents/research/Knowledge_Perception_and_Application_of_the_Mitigation_Hierarchy_Among_Officials_in_Canadian_Federal_Regulatory_and_Resource_Management_Agencies.pdf