The SWAT Approach for Pipeline Watercourse Crossings

Abstract

This paper describes a multi-year program to assess pipeline crossings of sensitive watercourses along a major pipeline project. During the Front End Engineering and Design (FEED) phase a sensitive watercourse assessment team (SWAT) was established to provide a biophysical and construction assessment of selected watercourses to be crossed by a proposed pipeline project in western Canada. The SWAT comprised a fisheries biologist, a pipeline watercourse construction specialist and other technical support personnel. The field work included assessing biophysical data, fish habitat values, access to the crossing location, construction issues, site-specific mitigative measures and potential habitat compensation options, as well as providing photo documentation and a conceptual crossing sketch. The advantages of the SWAT assessment at a crossing site were: • It provided an effective and efficient field assessment of the proposed watercourse crossing in the early phase of the project. • It was a multidisciplinary assessment. • It provided a recommendation as to a preferred crossing location at the site. • It provided a recommendation as to preferred crossing method and timing of construction at the site. • The data were site-specific to the preferred crossing location. Three consecutive years of baseline biophysical field data were compiled and site reports generated using a custom designed database. Over 200 sensitive watercourses were identified based on environmental, geotechnical, and constructability factors and were visited by the SWAT team, sometimes more than once, for a total of 271 individual site assessments. Data collected during the FEED phase included site-specific information that can be used for ongoing project discussions, regulatory and community consultations, permitting and Fisheries and Oceans Canada (DFO) authorizations. The SWAT program also provided recommendations for minor or significant shifts in crossing location for 40% of the sites visited, resulting in changes to the pipeline alignment during the route evolution process.