The Canadian Environmental Assessment Act mandates that environmental assessments are undertaken in the planning and proposal stages of projects that may impact the environment. Environmental Assessments evaluate the impact of a project on the environment and are used to advise decision making and to determine mitigation measures. Environmental Assessments include mandatory consultation with effected communities, including First Nations. Certain projects and government actions interact with environmental legislation such as the Fisheries Act and trigger mandatory environmental assessments.
In general, any action that causes a harmful alteration, disruption, or destruction of fish habitat or that will result in fish mortality in a way other than fishing requires an environmental assessment.