2024 – Are the New ALARP Guidelines More Conservative than Standards Based Criteria?

Sam Taubert, Chris Topham, Peter Tsoukalas

Many jurisdictions within the dam industry have been using risk assessment and the ALARP (As Low As Reasonably Practicable) principle for many years in order to assess the tolerability of public safety risks. In some jurisdictions legislation has also been implemented in regard to dam risk positions meeting the SFAIRP principle (So Far As Is Reasonably Practicable), a similar but subtly different and arguably more conservative test. As with risk analysis, consideration of the ALARP/SFAIRP principles requires subjective engineering judgements and it is necessary to develop a repeatable and defendable process. This paper focusses on application of the guidance provided for ALARP in the updated ANCOLD Risk Assessment Guidelines (2022) to an Extreme consequence category dam, with surprising results. Comprehensive consideration of each ALARP criteria is presented with practical guidance for future ALARP assessments provided. The paper then uses a case study dam to illustrate the impact of the new guidelines and ask the question: “is the new ALARP guidance achieving the objectives desired by the working group of the guidelines?” The outcome demonstrates the more holistic assessment required by the new guidance, validates that the new ALARP is an equivalent standard to SFAIRP, and obliges the owner to incorporate a wider range of non-structural measures into the ALARP solution. The paper concludes that, despite the case study outcome, the ALARP approach is not “more conservative” than a standards-based approach, it is more extensive and targeted to the specific site.