Planning methods for conjunctive use of urban water resources based on quantitative water demand estimation models and groundwater regulation index in Yangon City, Myanmar

Although planned and regulated conjunctive use of surface water and groundwater could help alleviate water shortages in developing countries, unregulated conjunctive use is common due to the lack of water consumption data and management plans. This study aimed to establish planning methods for conjunctive use of urban water resources in Yangon City, Myanmar, for which only limited data on water resources and consumption are available. To obtain accurate operational times for groundwater pumps, vibration loggers were attached to discharge pipes of the groundwater pumps owned by Yangon City Development Committee and households, and the water consumption of residents without piped water supply was estimated based on their housing types. Subsequently, the groundwater consumption by residential and commercial users was estimated from the water mass balance for Yangon City. It was found that the actual groundwater abstraction and consumption in Yangon City is far greater than the amounts reported in the Water Supply Master Plan of 2014. Groundwater abstraction per area (APA) was proposed as an index to prevent land subsidence, and the calculated values of APA for each township of Yangon City were very high compared with those of other Asian cities that have experienced land subsidence. Based on the APAs estimated for three future scenarios with two future water demands, this study calls for immediate regulation of industrial water to minimize the risk of land subsidence in Yangon City. The planning methods for conjunctive use proposed herein could be useful for other cities in developing countries where unplanned conjunctive use is prevalent. [Display omitted] •Novel planning methods of conjunctive water use for cities in developing countries.•Urban water balance model to estimate water consumption and water loss.•Mobile vibration data loggers to obtain operation times of groundwater pumps.•Abstraction per-area proposed as an index to assess the risk of land subsidence.•Phased regulations for groundwater abstraction to avert environmental impacts.