Integrated performance assessment of urban water systems: Identification and prioritization of one water approach indicators

Conventional water systems are facing challenges of increasing population, aging infrastructure, and climate change incidents. A paradigm shift towards integrated urban water management is desired, which is underpinned by the One Water Approach (OWA) concept. Assessment of integrated urban water system (IUWS) performance is required to manage urban water systems holistically. For this purpose OWA indictors are identified and prioritized in the present study. These indicators represent essential characteristics of water systems relationship, global sustainability attributes, infrastructure features in accommodating increasing water services demands, and holistic building of One Water Community. Twenty-nine indicators have been identified across five performance objectives and ranked by 35 municipal representatives. Fuzzy- Technique for Order Performance by Similarity to Ideal Solution) (F-TOPSIS) was employed to understand the impact of three decision criteria (sustainability, resiliency, and reliability) in identifying indicators and calculate their corresponding scores. Sustainability is a major criterion in identifying indicators, followed by resiliency and reliability. The achieved criteria scores were 0.764, 0.310, and 0.250, respectively. Fuzzy AHP (Analytical Hierarchical Process) was used to prioritize the OWA indicators. Rapid recovery from natural calamities was the top-ranked indicator followed by water leakage reduction, and public willingness to change behaviour, whilst GHG emissions from treatment plants is the bottom-ranked. Statistical analyses were conducted to discern variability in performance scores and determine relationship between decision criteria in indicators identification process. The findings from this study will open new avenues for policy-makers to improve urban water sustainability, resiliency, and reliability by assessing water system performance in an integrated manner to achieve OWA goals.