The suitability of risk reduction indicators to inform dam safety management

Abstract

Risk analysis can provide very suitable and useful information to manage the safety of critical civil infrastructures. Indeed, results of quantitative risk models can be used to inform prioritisation of safety investments on infrastructures’ assets and portfolios. In order to inform this prioritisation, a series of risk reduction indicators can be used. This paper reviews existing indicators for dam safety, tracks how equity and efficiency principles are captured, propose additional indicators and provides insights into how tolerability guidelines and benefit–cost analysis can also play a role in decision-making. All reviewed, analysed and/or combined indicators are later applied in a case study, a portfolio of 27 dams where 93 structural and non-structural investments are prioritised. The case study shows that prioritisation sequences based on risk model results provide suitable and useful information, acknowledging that other concerns may be conditioning decision-making processes. With the results of the case study, a full comparison between all studied risk reduction indicators is made, and three indexes are calculated for all of them to measure how close they are to a theoretical best.

Keywords:

• Dam safety
• decision-making
• risk management
• risk & probability analysis
• quantitative analysis
• risk reduction indicators
• risk reduction principles
• equity & efficiency

Notes

No potential conflict of interest was reported by the authors.

1 Under certain circumstances, due to nonlinearities in the application of risk reduction measures, it is possible that this strategy will not yield the absolute optimum sequence. In these cases, the optimum sequence can still be obtained, but it is computationally more costly. However, the sequence obtained with the simple iterative strategy is typically either optimal or very close to optimal and will therefore be used throughout the paper.

Additional information

Funding

The Spanish Ministry of Economy and Competitiveness (MINECO) has supported the work described in this paper through the research project entitled IPRESARA (Incorporating man-made risk components into general dam risk management [BIA 2010-17852]) within the period 2011–2013 and the project INICIA (Methodology for assessing investments on water cycle infrastructures informed on risk and energy efficiency indicators [BIA 2013-48157-C2-1-R]) within the period 2014–2016.