Even with the availability of urban water services, nearly half of the global urban population still relies on groundwater.
In Southeast Asia, many urban water supply systems are increasingly stretched to breaking point by sprawling urbanization, industrial demands and economic growth. Combined with inefficiencies in urban water use and degraded water quality from pollution, many urban communities have no choice but to draw on groundwater for their daily needs.
According to the 2022 UN World Water Development Report on Groundwater, the key challenge facing groundwater resources is the excessive abstraction for domestic and non-domestic consumption.
In cities with limited water catchment areas, groundwater recharge might not keep up with the abstraction pace. It often causes side effects, such as land subsidence that accelerates the sinking cities phenomenon in municipalities such as Bangkok.
Urban water systems and groundwater
Urban water systems and groundwater are interlinked, in which enhancing urban water use through demand management strategies could potentially ease the pressure on groundwater resources.
At least three major challenges affect the efficiency of urban water, namely technical, administrative, and consumer preferences.
First, the technical challenges of urban water service occur in the distribution network, which include water losses and intended or unintended overconsumption. Water losses include physical losses occurring along the distribution line, such as leakage and pipe bursts, and commercial losses, such as meter reading faulty and illegal connections. Both losses cause non-revenue water or lost income for the water utilities.
Meanwhile, overconsumption in homes such as the use of piped water for gardening and water intensive household devices adds unnecessary pressure to urban water systems.
Second, administrative issues often prove a persistent challenge. In cities with vast informal settlements, such as Bangkok, Jakarta and Manila, water utilities are often unable to extend their connections to these settlements due to the uncertain tenure status and the absence of permanent addresses. As a result, the residents in informal settlements often get water access from outside of their premises or dig boreholes for groundwater.
Lastly, urban water services may not always be affordable to many given the upfront installation cost and the monthly water bills compared to the “free” water pumped out of the ground. Moreover, biased consumer preferences also hinder the use of urban water service. Despite the urban water treatment systems that make water suitable for drinking, many customers do not fully trust its quality. In turn, this results in many households trying to seek alternative water sources for cooking and domestic use.
Even when the technical, administrative, cost and consumer preference challenges are addressed, certain urban water services still rely on groundwater for their main raw water sources. As a result, improving water use efficiency is always critical.
Urban Water Demand Management
Urban water demand management (WDM) has been used for reducing urban water consumption through efficiency enhancement in water-scarce regions, such as the Middle East, Australia and Singapore. WDM ensures reduction in overall water consumption and eventually groundwater (over-)extraction.
Several of the most common measures used in urban WDM include tariff setting, water loss reduction, water-saving devices and finding alternative water sources.
Tariff setting in urban water should ideally reflect cost recovery with an increasing block tariff scheme. Consumers are charged higher prices for higher consumption, hence nudging them to reduce consumption. Water utilities also implement multiple strategies to reduce water losses, such as leak detection technologies and meter reading upgrades.
On the consumer side, water-saving devices can help them cut their water consumption without having to consciously plan for it. However, using these devices also means paying an upfront cost to purchase and install them.
Customers can also use alternative water sources such as rainwater harvesting for non-potable consumption like toilets, car washing and gardening. Utilities in many countries are also exploring alternative water sources like seawater desalination and water recycling to increase raw water supply. These strategies often come with rebate programme for customers to encourage higher adoption rate.
Implementing urban WDM measures provides a range of benefits. For consumers, the improvement in water consumption efficiency will help reduce their water bills. Water utilities benefit from efficient water consumption as their water distribution networks are often overstretched to treat and distribute clean water across sprawling urban areas.
Lastly, many water utilities in the region are fully or partially run by the government. WDM measures can reduce the pressure on public finances allocated through tariff subsidies and the water utility’s operational costs.
In combination with urban WMD, governments also need to incrementally strengthen regulations for groundwater use.
In designing urban WDM policies, policymakers should ask themselves: do the ends (efficient urban water and thus less reliance on groundwater) justify the means (WDM policies) or is it the other way around?
For instance, imposing a tariff structure that reflects cost-recovery, albeit proven effective to improve efficiency, may deprive low-income households from accessing clean water. At the same time, staying at the status quo of inefficient urban water will continue pressuring groundwater resources which cause other bigger problems, such as land subsidence.
There is no right or wrong approach to urban water management as it is very much context dependent. However, policymakers need to also reflect on the intended and unintended consequences of their choices given that access to clean water is a basic human right.