Offset sizing tools: A review of practices used in the field and their operationality

The mitigation hierarchy (avoid, minimize, restore/rehabilitate and, lastly, offset or compensate) is one of the key regulatory mechanisms that exists to include biodiversity protection in land-use planning. Implementing the mitigation hierarchy requires the use by practitioners (developers, environmental consultants and government agencies) of operational mitigation assessment methods, or offset sizing methods. This study focused on one aspect of operationality: usefulness. Through an approach based on ergonomics, we analysed practices used in the field in order to concretely identify in what way an offset sizing method is useful to developers, consultants and public officials. The findings showed that sizing offset measures is a collective process involving all these stakeholders, that these practitioners vary significantly in their level of knowledge about ecology and their degree of expertise in the mitigation hierarchy, and that each method is not equally useful for each type of stakeholder. Our conclusion is that to improve operationality, these methods must be adapted into tools that are relevant to the specific user and context.