Optimizing Rural Drinking Water Supply Infrastructure to Account for Spatial Variations in Groundwater Quality and Household Welfare in Coastal Bangladesh

Orlando Roman,Jim W Hall,Mohammad Monirul Alam,Sonia Ferdous Hoque,Mashfiqus Salehin,Robert Hope,Lucinda Ford

doi:10.1029/2021wr029621

Abstract

AbstractAchieving water security requires reconciling multiple objectives while prioritizing scarce resources for the provision of safe drinking water supplies. We examine decision‐making to invest in drinking water infrastructure in coastal Bangladesh where increasing saline intrusion in aquifers intersects with high levels of poverty for the 20 million people living in the coastal region. Multi‐objective optimization is used to explore the trade‐offs between two public policy goals: (a) maximizing overall access to improved water supplies (the greater good) and (b) maximizing access for the population with the lowest welfare (the greater need). To elucidate this trade‐off, we make use of groundwater salinity measurements, an extensive household survey and an audit of drinking water infrastructure in 1 out of Bangladesh’s 139 polders, which is home to nearly 60,000 people. We quantify the costs of a variety of drinking water supply options including deep tube wells, desalination plants, and piped systems. The recommended solutions are sequences of investments in water supply assets that are optimized to specified locations within the polder. The method is potentially scalable and transferrable to inform investments to achieve the Sustainable Development Goal (Target 6.1) of universal access to safe and affordable drinking water.

Highlights

The 2030 Agenda for Sustainable Development, as articulated in Target 6.1, aims to achieve universal and equitable access to safe and affordable drinking water, using the proportion of population using safely managed drinking water services as the associated indicator (UN, 2015)
We examine decision-making to invest in drinking water infrastructure in coastal Bangladesh where increasing saline intrusion in aquifers intersects with high levels of poverty for the 20 million people living in the coastal region
We focused on three objectives: (a) maximize the total population served with safe drinking water supplies, (b) maximize the number of low

Summary

Introduction

The 2030 Agenda for Sustainable Development, as articulated in Target 6.1, aims to achieve universal and equitable access to safe and affordable drinking water, using the proportion of population using safely managed drinking water services as the associated indicator (UN, 2015). Despite the progress in increasing “access” to technologically improved sources as part of the Millennium Development Goals (MDG), as of 2017, over 2 billion people lack safely managed drinking water and 785 million do not even have “basic” services (WHO/UNICEF, 2019). Progress to improve water security is most challenging in contexts where financial and institutional resources are limited and where water resources are threatened by chronic (e.g., groundwater contamination) and acute (e.g., floods and cyclones) threats. Bangladesh typifies these chronic and idiosyncratic water security risks, in the coastal region, where around 20 million people live precarious lives with uncertain futures A. Hoque et al, 2016; Shammi et al, 2017)

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