ASSESSMENT OF BILLED-UNMETERED WATER CONSUMPTION TO IMPROVE WATER UTILITY MANAGEMENT IN YANGON CITY

抄録

 High rates of non-revenue water (NRW) are the main obstacle against improvements of water utility management in many Asian cities. Yangon City, Myanmar, has a high NRW rate of ca. 60%. Previously billed-unmetered consumption, which is often caused by damaged water meters, was classified to revenue water by International Water Association, but later it was redefined as non-recovered revenue water. Although billed-unmetered consumption could cause a significant revenue loss if there is a large discrepancy between billed and real water consumption, there has been no report of estimating the amounts of billed-unmetered consumption in Asian cities including Yangon. Therefore, this study aimed to estimate the revenue increase by replacing damaged water meters with new meters, and thereby to estimate the factors influencing water consumption. The water consumption in three townships with large or ordinary houses were measured on site and the water consumption before and after meter replacement was measured in a pilot study area. The water consumption per connection was influenced by the number of persons per house, but the per-capita consumption was significantly greater and varied in the large houses than the ordinary houses due to non-essential water consumption such as watering gardens and filling swimming pools at the fixed rates of water bills. After water meter replacement, the revenue increased by 2.6 times or 1.8 times in large or ordinary houses, respectively. Thus, the cost of meter replacement could be recovered in eight or 25 months for large and ordinary houses, respectively. Therefore, it was found that, despite limited budget of water utilities and rules of private ownership of water meters, it is recommended to replace water meters to increase their revenue and to save non-essential water consumption by raising the awareness of the consumers through sending bills of their real water consumption.