Environmental assessment framework for identifying and mitigating the effects of linear development to wetlands

Notwithstanding various environmental assessment legislations and policies for wetland conservation in Canada, wetland habitat continues to be lost to the cumulative effects of development on the landscape. Ensuring no net loss of wetlands requires consideration of the direct, indirect, and potentially induced effects of development; however, many projects that affect wetlands are often deemed insignificant and do not trigger any formal environmental assessment process. When such small scale or routine projects are assessed, indirect and induced effects, and in particular effects to small or seasonal wetlands, are often not included in impact assessment and subsequent wetland mitigation. As a result, mitigation of the total or cumulative effects to wetlands is often insufficient or completely lacking in development planning and impact assessment. Part of the problem is that there currently exists only limited guidance as to how to identify effects to wetlands in project planning and environmental assessment for relatively routine, small-scale projects. In response, this paper presents a methodological framework for the integration of effects to wetlands in project planning and environmental assessment application. Focused on effects to wetlands from linear developments, in particular transportation corridors, a four-phase, nine-step assessment framework is developed to provide guidance to effects assessment for wetlands during the early stages of project planning. The framework will aid practitioners and regulators in identifying the potential effects of a project to wetlands, and in determining the acceptability of impact management practices. Although situated in the Canadian context, the framework and principles are broadly applicable in other jurisdictions.

Research highlights▶ Most projects that affect wetlands are deemed insignificant and go unmanaged. ▶ Assessing total effects to wetlands is insufficient in current EA practice. ▶ A framework to assess effects to wetlands in project planning and EA is presented. ▶ No net loss requires that EA consider direct, indirect, and induced effects. ▶ Assessing wetland effects must be sensitive to the constraints of small project EA.