INVESTIGATING THE DETERMINANTS OF DOMESTIC WATER SUPPLY AND CONSUMPTION IN INDIAN CITIES

Abstract

The sixth Sustainable Development Goal (SDG) emphasises adequate access to water and sanitation for all. SDG-6 highlights that the water supply volume for domestic use should be equitable, i.e., every citizen should be able to access their daily water requirement. The water consumers require water for daily use, which is expressed as water demand. Water demands reflect the water requirement for daily activities, while the water supply reflects the quantity of water distributed by the supply utility. When the water supply is less than the water demand, the water consumers either try to adjust for the supplied quantity or collect water from private sources and self-supply. Water consumption refers to the water usage for daily purposes by consumers from both public supply and private sources or self-supply. The present study investigates the critical determinants of water supply and consumption in Indian cities. Multiple standards and benchmarks have been established around the world to estimate the water supply service performance. There are two critical indicators to evaluate the performance of water supply services: (i) water supply continuity, i.e., average hours of supply per day, and (ii) average per capita water supply levels. In India, the Ministry of Urban and Housing Affairs defines 24 hours of supply continuity as the Service Level Benchmark (SLB) for per capita water supply. However, several Indian cities fail to achieve the benchmark due to existing intermittent water supply (IWS). The existing literature on water supply intermittency focuses primarily on its characteristics, causes, and challenges. However, the pattern of IWS within the city, i.e., how supply hours, days, and frequency of the water supply vary among city localities, is not widely studied. It is essential to understand which localities within the city have higher supply hours and which receive fewer hours. Similarly, the per capita water supply has an SLB of 135 litres per capita per day (lpcd). The Ministry of Housing and Urban Affairs of India requires all Indian cities to achieve an average of 135 lpcd of water supply to be considered efficient. However, the Handbook on Service Level benchmarking guideline also states that the key limitation of this indicator is that it provides information on a city-wide basis and does not reveal intra-city variations. There is a need to study the intra-city variation of water supply in Indian cities. Therefore, the present study has examined the interrelationships between the water supply SLB indicators in Indian metropolitan cities. Further, the spatial pattern of water supply continuity within Hyderabad city has been studied. The study tests the hypothesis that the average domestic water consumption follows the SLB of 135 lpcd in Indian metropolitan cities. Finally, the key determinants of domestic water consumption have been investigated in Indian metropolitan cities. Hyderabad, India’s fourth most populous city, has been considered as a study area due to high intermittency levels and dependency on multiple sources of water. Rapid urbanisation and population growth have increased the water demand in the city. The authorities have augmented the water from rivers over 200 kilometres from the city to address the increasing demand, incurring enormous infrastructure investments. In Hyderabad, the Greater Hyderabad Municipal Corporation (GHMC) is accountable for urban administration and governance. At the same time, water supply is the function of the Hyderabad Metropolitan Water Supply and Sewerage Board (HMWSSB). The expert opinion survey was performed to identify the interrelationships between the SLB indicators of water supply using Interpretive Structural Modelling (ISM). Further, Multiple Regression Analysis, fuzzy set Qualitative Comparative Analysis (fsQCA), and Data Envelopment Analysis (DEA) have been used to assess the water supply performance in Indian cities. The spatial patterns in water supply continuity have been studied based on the secondary data collected from the HMWSSB. Spatial autocorrelation, Kernel Density Estimation (KDE), and Geographically Weighted Regression (GWR) have been used to study the spatial patterns of water supply continuity with respect to the population densities in different wards of the study area. The data for water consumption has been collected from the primary source using a sample survey for hypothesis testing and spatial variation of water consumption in the study area. The one-sample t-test was used to test the null hypothesis of average water consumption in the study area, which is not different from the 135 lpcd benchmark. The influence of different water consumption determinants has been identified using Classification and Regression Trees (CART). The Relative Importance Index (RII) and Relative to Identified Distribution (RIDIT) have been used to understand the user perception of the importance of determinants of water consumption. Finally, GWR is used to study the spatial variation of water consumption determinants in the study area. The present study has identified that the water supply coverage, metering, continuity, and non-revenue water are vital determinants of per capita water supply in Indian cities. Water supply continuity has been higher in the central parts of the city and lower in peripheral areas of the study area. The per capita water consumption at the household level is similar to 135 lpcd in the winter season and annually. In comparison, it is significantly different from 135 lpcd in the summer and rainy seasons. However, the average per capita water consumption is significantly similar to the benchmark at the circle level. Further, household characteristics, supply characteristics, climate and consumer behaviour have been identified as significant determinants of water consumption in the study area. Multiple recommendations have been made from the present study for the different stakeholders of urban water supply management. Five critical stakeholders identified for the present study include Urban Planners, Supply Utility, End Users, Researchers, and Policymakers. The present study has studied the interrelationships between the Service Level Benchmarking indicators in India. The study also adds the scope of improvement in per capita water supply and cost recovery by reducing the non-revenue water levels, which cities should prioritise over augmenting water from alternate sources. The present study has established a need to understand both the physical and financial loss components of non-revenue water exclusively in order to study the impact on per capita water supply levels in Indian cities. Further, the predominant amount of existing literature focuses on the causes and challenges of the intermittent water supply in urban areas. The present study indicates that water supply continuity also has spatial inequity, similar to water supply volume and coverage of connections in the urban periphery. The average per capita water consumption at the household level depicts a significant difference from the SLB of 135 lpcd in summer and rainy seasons. At the same time, it is similar in the winter season and annually. However, the average per capita water consumption at the larger spatial units of analysis, such as a circle (indicates sub-city level), is similar to 135 lpcd in all seasons. These results indicate that the water demand assessments need to understand the spatial and seasonal variabilities carefully to plan and implement water infrastructure projects. The present study has a significant contribution to the existing knowledge on water consumption determinants, especially in the Indian context. For example, old buildings in Indian cities have demonstrated lower water consumption as these households usually have traditional water usage methods, such as buckets for bathing instead of showerheads. The results of the study shall be helpful to urban planners, water utilities, and policymakers in understanding the essential characteristics of water supply and consumption in Indian cities.