Case Study - Warragul to Moe Water Supply Interconnect - Gippsland Water

Abstract

At a total project cost of $15M the Warragul to Moe water supply interconnect addresses the shortfall in the Tarago (Warragul) system. The project provides operational security and flexibility to transfer water in both directions up to 8ML per day between the Moe and Tarago systems in the event of supply shortfall and water quality events. Stage 2 of the Warragul to Moe interconnect, constructed by Jaydo Construction in 2018/19, involved 8.3km of DN375 water main from Darnum to Warragul. Trenchless construction included five Horizontal Directional Drill (HDD) DN450 PE bores ranging in lengths from 100m to 250m under waterways and significant flora and fauna, and the installation of a 150m long DN500 GRP microtunnel bore beneath a railway and freeway. This paper provides an overview of the project and discusses changes undertaken during construction to provide risk minimisation and cost savings. Another focus of this paper is on the recovery of the stuck microtunnel boring machine (MTBM) beneath the rail line and discusses the recovery options, methodology, rectification works and key learnings.