To Dig, or Not to Dig: That Is the Question. Improving Environmental, Cultural and Archaeological Outcomes Through Using Trenchless Construction Solutions Over Traditional Open-Cut Methods

Abstract

The Lockerbie Main Sewer Project is a 9 km sewer on Wurundjeri Woi-wurrung Country that was installed through a combination of construction methods. This paper explores the true tangible and intangible costs and program implications of large-scale construction in areas of environmental or cultural significance. It considers the merit of preserving ecological and cultural values through selecting trenchless technology over open cut construction. The project utilised targeted trenchless construction to avoid harming 9 cultural sites. This improved environmental outcomes through reducing construction impacts, while enabling sewer construction at greater depths to service a larger area. In some sections, the real cost of selecting open-cut methods was much higher than if trenchless had been employed, despite direct comparison between fee estimates. Other costs included those associated with cultural heritage salvage conditions, program impacts, and flow-on effects to key stakeholders. It was found that current options assessments do not factor the true cost of disturbing areas of ecological, cultural, and archaeological sensitivity. Extensive engagement with the Wurundjeri Woi-Wurrung Cultural Heritage Aboriginal Corporation (Wurundjeri Corporation) was key to mitigating these challenges. The strong relationship ensured that the project could quickly update salvage requirements to suit changing site conditions, manage resource availability for salvage activities, and modify trenchless layouts to further improve heritage outcomes. This relationship ultimately led to a ground-breaking collaborative research project with Wurundjeri Corporation, which has provided culturally meaningful results to Wurundjeri Woi-wurrung people and the broader community. Overall, the project sets a template for future heritage engagement in civil construction. 1 No-Dig Down Under 2023 To dig, or not to dig: that is the question. Improving environmental, cultural and archaeological outcomes through using trenchless construction solutions over traditional open-cut methods Orry Thomas, Amanda Goldfarb, Ron Jones, Allan Wandin, Bobby Mullins, Ross Mallinson, Caroline Spry, Nina Braid