Comparison of capacity and length of distribution pipe as performance indicators: a case study at stationary business environment utilities in Japan for the past 20 years

The abstract showing the ratio per length and ratio per capacity showed different trend in terms of ineffective water management. The water utilities sector is impacted by various factors, including population growth, urbanisation, climate change, technological advancements, and an ageing population. Enhancing the management of water utilities is crucial, and this can be achieved by using pre-existing performance indicators and incorporating the findings of research on innovative performance indicators. First, we conducted an analysis using ‘distribution pipe capacity’ as an alternative performance indicator. Second, we tracked changes to these indicators in a stationary business environment utility. Third, we compared the trends of these indicators with those of existing performance indicators to establish correlations. Analysis of data from the past 20 years revealed that the capacity and length of distribution pipes increased, while the maximum daily supply decreased. Earthquake resistance in 2020 was higher in the capacity decrease and length increase groups. The rate of change in the amount of ineffective water was found to be significantly suppressed in the capacity decrease group compared with the capacity increase group (p < 0.10), while the indicator was not significantly different between the length increase and decrease groups. Finally, a breakdown analysis by service population revealed a significant difference in the rate of change in the amount of ineffective water across different service population categories.