Root cause failure assessment of a water retention reservoir at a mining industry Site

Abstract

This paper reports on an investigation into the failure of a double HDPE geomembrane lined retention reservoir constructed in 2018 that failed in 2021, only 3 years after construction. Several technical and non-technical factors contributed to the failure, and these are examined systematically. The primary failure occurred at the outlet pipe penetration, where the design detail had been modified due to constructability issues. Several administrative failures were also identified during the investigation, the most significant of which was the absence of a comprehensive construction report with a concluding statement from the engineer of record verifying the structure was constructed in accordance with the design and specifications and is fit for purpose. The failure highlights the need to better integrate design and construction teams and to keep impeccable records of all technical decisions.