Risk-Based Asset Inspection Priorisation Programme

Wanganui District Council (WDC) has been undertaking a master planning exercise for its wastewater and stormwater networks. This includes prioritising its condition assessments and renewals programmes. 

In order to make sure condition assessment investments were cost effective, WDC primarily wanted to prioritise proactive CCTV inspections based on the criticality, or consequence of failure while also taking into account the age/material index of the asset. The total business risk as a product of criticality and the likelihood of failure was identified as a secondary mechanism of prioritisation. A very broad range of criteria were considered in the identification of critical assets. 

The prioritised results will be used to direct condition assessments going forward in the required 30 year asset management plan. 

This paper explores the methodology adopted in this project, how it differs from more routine risk based assessments and how the results were able to then be used to programme the condition assessments and subsequent renewals. It will be of interest to readers who manage network assets and wish to be able to prove they are doing so in an efficient and cost effective manner.