A Risk Assessment Tool for Evaluating Geohazards and Fisheries Sensitivity at Pipeline Water Crossings

The Fisheries Act legislates Fisheries & Oceans Canada (DFO) to regulate all development activities affecting fish-bearing waters to ensure no net loss in habitat productivity. To meet the increasing regulatory demands of oil and gas development, DFO is developing a Fisheries Risk Assessment Tool (FRAT). The current focus is along the Mackenzie River Valley, Northwest Territories. The FRAT is applied to proposed pipeline stream crossings and evaluates the risk to fisheries resources from geohazards causing sedimentation impacts. Ultimately, the FRAT may be applied across Canada to streamline DFO’s regulatory process for pipeline stream crossings. The FRAT consists of a Geophysical Database that characterizes physical attributes of the river valley and channel in the vicinity of a crossing, plus a Fisheries Database that characterizes the fisheries resources and habitat of the stream. Algorithms have been developed to quantitatively estimate sedimentation hazard likelihood and fisheries sensitivity, which are coupled in a qualitative risk matrix that assigns an overall risk rating to each stream crossing. The overall risk rating then designates the level of regulatory review and authorization process carried out by DFO under the Fisheries Act. Geohazard algorithms are being calibrated and tested using field data and stream crossing construction scenarios are being incorporated into the risk assessment tool. This paper describes the FRAT and its application in the Mackenzie Valley, and presents preliminary results from risk analysis of pipeline stream crossings.