Post-earthquake performance indicators for sewerage systems

Abstract

This paper presents a set of performance indicators (PIs) for assessing loss of wastewater service and the induced functional impacts in three different phases: emergency response, short-term recovery and long-term restoration. Built on the experience and learning of the Stronger Christchurch Infrastructure Rebuild Team in reinstating the resilience of the Christchurch wastewater system following the Canterbury Earthquakes in 2010–2011, the developed PIs aim to evaluate holistically the structural, hydraulic, environmental, social and economic consequences that might arise due to the earthquake-induced physical damage to sewerage components. This includes sewer pipelines, pumping stations, manholes and council-owned laterals. Furthermore, a framework in which the proposed PIs are integrated into is introduced for demonstrating practical applications. The decision support framework includes three modules, namely: (a) physical damage module, (b) functional impact module and (c) serviceability restoration module. The framework is intended to support the decision-making process in terms of restoration strategy selection and resource allocation in the move towards an effective and informed reinstatement of sewerage systems after earthquakes.