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Groundwater, Aelf-supply and Poor Urban Dwellers

This article was adapted from the paper, Groundwater, self-supply and poor urban dwellers: A review with case studies of Bangalore and Lusaka Jenny T. Grönwall, Martin Mulenga, Gordon McGranahan, published on the International Institute for Environment and Development website (IIED).

The International Institute for Environment and Development is a global leader in sustainable development. As an independent international research organisation, the group specializes in linking local to global. In Africa, Asia, the Caribbean, Central and South America, the Middle East and the Pacific, they work with some of the world's most vulnerable people to ensure they have a say in the policy arenas that most closely affect them — from village councils to international conventions.

Through close collaboration with partners at the grassroots, they make research and advocacy relevant to their needs and alive to their realities.

Download Groundwater, Self-supply and Poor Urban Dwellers

Introduction

PagesfromGroundwaterself-supplyandpoorurbandwellers-3.jpgHundreds of millions of people in low-income urban settlements rely on wells for drinking and other domestic purposes. Efforts to enhance the quality, reliability and sustainability of these water sources receive little attention, locally and internationally. The implicit justification is that wells do not provide adequate water, but that little can be done to improve these sup­plies as they are essentially a residual that needs to be eliminated by the continued expan­sion of piped water systems. For the poorest urban households in many Asian and African countries, however, far from being a small and declining residual, these groundwater sources are vital. Of all the countries surveyed, this group reports the greatest dependence on wells as the main source of drinking water.

While it is hard to generalise about the possibilities for improving these groundwater sup­plies, hydrogeological assessments, water quality monitoring, point-of-use treatment, and the upgrading of sanitation facilities, among others, all have important roles to play if applied ap­propriately and in the right circumstances.

The objectives of this review are:

  • to explore the extent to which urban dwellers, and especially those living in low-income areas, depend directly and indirectly on groundwater 
  • to explore the difficulties they face as a result
  • to raise awareness of and emphasise the need for better integration of groundwater in the planning and management of urban water resources.

The paper is based on a review of literature, substantiated by two case studies of Bangalore, India, and Lusaka, Zambia, and discussions with experts. The study on Bangalore builds on PhD and post-doctoral research carried out by Jenny Grönwall during six field trips between 2005 and 2007 (Grönwall 2008) and in 2009. The Bangalore study included a survey of close to 300 households. The Lusaka study builds on research conducted by Martin Mulenga dur­ing field trips in 2004 (Mulenga, Manase et al. 2004) and 2010. In both cities, views were sought from people in the relevant authorities, NGOs and slum/low-income settlement areas. Field trips also allowed for observations of some of the development over the past four to six years, as well as insights into the general situation of other Indian and Zambian cities.

The conditions in Bangalore are fairly typical of cities in India and elsewhere which are un­derlain by low-yielding weathered crystalline bedrock, However, Lusaka’s karst terrain cre­ates a groundwater access problem which consists less in the quantities available and more in the poor quality of the water. Consequently, the two cities have responded differently to their different situations. Indeed, one of the lessons learned is that local hydrogeological conditions, together with the cultural and political situation, influences the strategies of the poor for accessing water, and the strategies of city governments and utilities for providing it. Our attempts to draw general conclusions must be tempered by this importance of locality.

In order to substantiate the literature and the two case studies, we analysed statistics from USAID’s Demographic and Health Surveys (DHS) on people’s sources of water for drinking and other domestic purposes, with the help of statisticians at the University of Southampton. The DHS, together with similar surveys, helps to evaluate progress towards the Millennium Development Goals’ (MDGs).

Self-supply, and the direct and indirect use of groundwater

This paper is concerned primarily with what we define as the urban self-supply of water and the direct use of local wells by low-income households. Direct use refers to water drawn or pumped from wells, which is consumed by or delivered directly to households in the same neighbourhood. It is not mixed or delivered with other sources, as when a piped water net­work relies in part on groundwater. The well may be one’s own or a community well, or someone else’s. The water will often be available for free, but is sometimes purchased. It may be taken from a shallow dug well or pumped from a deep borehole. It may be used only by nearby households, or maybe distributed via pipes, trucks or carts to more distant house­holds. The important point is that while such water is seldom taken into account or planned for in either water resource assessments or city water safety plans, it is often of vital impor­tance to a large proportion of a city’s inhabitants.

By indirect use of groundwater, we primarily mean groundwater provided through pipes, tubes and mains that forms part of a public or private utility’s reticulated water supply system. This mostly means that the supplier makes conjunctive use of water from both surface water sources and aquifers. Where the utility takes water from well-fields or springs situated out­side the city and trucks it to customers – including those living in low-income settlements and slums – it is also considered an indirect use of groundwater. Where there is conjunctive use of groundwater, city planners tend to have a better level of knowledge of the wells and groundwater conditions.

There can be no exact division between the two categories. Indirect use of groundwater may be monitored and measured by the utility that provides it, but it is not always categorised in official water statistics. Most direct use of groundwater is not monitored at all. Households with their own well are aware that they are using groundwater, but may be less aware of the quantities involved or whether the well can be depended on in the long term. Other ground­water users do not always know whether the water comes from aquifers or a surface water body if the water is delivered via a tap or container. Household surveys may ask whether households are using well water, but such surveys underestimate groundwater dependence because they neglect indirect groundwater use and do not identify all direct use.

Our definition of the self-supply of water in the urban context recognises that a large propor­tion of the urban poor depend directly on groundwater. Self-supply has become essential for those who are not served by the public utility, and for those who need to complement an in­adequate supply received via the household connection. Sourcing water from aquifers via different kinds of wells is a local, small-scale method used where hydrogeological and other factors allow. Investments can be made to construct wells both at household and community level. The feasibility of digging shallow wells – together with space requirements – tends to determine whether individual or shared solutions are more common. Community boreholes and deeper dug wells may have been constructed by NGOs (sometimes in villages that have subsequently been merged with a growing adjacent city). Water from such wells is less likely to be distributed for free; users may have had to contribute financially both for their construc­tion and subsequently for the water itself.

Our definition of self-supply has an area which is less clear-cut: it includes people who rely on groundwater via public taps and standpipes, or purchase it from a private vendor. Al­though these people do not have control over the source as they would if they had access to their own or a shared well, this practice is included in our definition of self-supply because they are not, or not adequately, served by the public system, and must therefore provide for their own needs.

There is a grey area also in regard to self-supply in the sense that poor people who rely on (ground)water via public taps and standpipes or purchase (ground)water from a private     vendor are not so much in charge of the source as if they have access to their own or a shared well. Equally, they are not, or not adequately, served by the public system and must therefore provide for their own needs.

Trends in urban groundwater use

This paper draws on aggregate statistics produced and analysed specifically for this study. The survey evidence is based on USAID’s Demographic and Health Surveys (DHS) on sources of water used for drinking purposes.

The analyses show that an estimated 269 million urban dwellers depend on wells as their principal source of drinking water. In urban Nigeria, it is estimated that almost 60 per cent of the population use local wells. This rapidly increasing trend seems to be partly due to peo­ple’s need to self-supply for lack of alternative sources, and partly due to cheaper borehole drilling technologies. Many more urban dwellers in the surveyed countries can, however, be presumed to depend both directly, and even more indirectly, on groundwater distributed via taps (defined as ‘piped water’). For instance, in urban Zambia only 18 per cent is officially reported to use wells, but our case study of Lusaka suggests that many more urban resi­dents depend on wells. This under-reporting may be partly because many people with dug, shallow wells may not want to admit that they use them, since such wells are banned by the authorities.

It is difficult to discern a general trend from the very varied patterns of urban direct depend­ence on groundwater; there is great variation between the surveyed countries, especially in Sub-Saharan Africa and Asia. In principle, a reported increase in the use of groundwater could be a positive sign, reflecting projects and policies that are successfully expanding the number of wells, and thereby improving water access by poor people. There are, neverthe­less, situations where increasing direct dependence on groundwater is a symptom of prob­lems that need to be addressed.

Groundwater, the Millennium Development Goals and quality issues

In the quest to achieve Target 10 of the Millennium Development Goals – to halve the pro­portion of people without sustainable access to safe drinking water and basic sanitation by 2015 – proxy indicators are used to define ‘improved’ sources of water and sanitation. Groundwater distributed by pipes and taps, including public standpipes, is regarded as im­proved. Likewise, tubewells, deep boreholes and ‘protected’ dug wells and springs are im­proved sources of water. Unlined dug wells that are not protected from runoff surface water by being raised above the ground and equipped with a platform, or covered to protect it from bird droppings and animals, are defined as unimproved on the grounds  of water safety. However, this definition is flawed, as even protected wells can yield non-potable water; in­deed, where the groundwater is contaminated, an ‘improved’ well offers no real protection at all. Similarly, several latrine types, including some in the ‘improved’ sanitation categories, al­low faecal matter to percolate out into the groundwater.

Many poor urban dwellers in African and Asian countries rely on getting water from open, shallow dug wells, often drawing it by hand. While these wells are considered ‘unprotected’, the fact that they provide easy access to water is actually advantageous for users’ health: increased quantities of water promotes good hygiene, and can prevent the faecal-oral trans­mission of endemic diarrhoeal diseases.

However, good water quality is also important. Urban groundwater resources are highly vul­nerable to pollution from human activities. For instance, in tropical Africa the incidence of childhood diarrhoea rises substantially during rainy seasons when pathogenic contamination of drinking water sources occurs. During the dry seasons, though, good availability of water rather than its quality tends to reduce the incidence of diarrhoeal disease.

During the rainy seasons in particular, there is thus a central nexus between the manage­ment of urban groundwater resources on the one hand, and the infrastructure for solid waste disposal, drainage, sanitation, and so on, on the other. The lack of water supply and sanita­tion coverage goes hand-in-hand in low-income settlements and the practice of using simple pit latrines (or open defecation) may have a detrimental impact on the local water source as most sewage and solid waste is discharged without treatment. Faecal matter containing pathogens may be washed straight into open wells, particularly during the rainy season. Con­taminated water, including wastewater from latrines, may also pollute aquifers by seepage through the ground.

Considering that many people who live in slums and low-income areas would benefit from access to more water than is currently available to them, it is important not to discourage people from using water from ‘unimproved’ wells. Instead, the emphasis needs to be on maintaining this resource’s quality, combined with education about hand-washing and other hygiene measures. Awareness-raising about the various transmission routes for diarrhoea and the importance of safe water storage in the home is often more vital than the quality of the water source used, as not all water used needs to be of potable standard. This is a les­son learned in Lusaka, where a large number of residents in the low-income areas have dug their own wells and thereby benefit from improved access to water within a short distance. Rather than the existence of shallow wells, environmental conditions such as the lack of sanitation, drainage, and solid waste disposal infrastructure, along with poor hygiene aware­ness, are to blame for ill-health. Diarrhoeal disease is endemic, and cholera outbreaks are regular, yet the use of chlorine or other water treatment methods is irregular.

The public health messages given to the residents of Lusaka’s low-income settlements are contradictory: on the one hand, measures are taken to steer households from using their own, dug wells for fear of poor water quality; on the other, adequate water access is not pro­vided. During cholera outbreaks, chlorine and soap is distributed, either subsidised or for free, by the health authority, foreign donors and NGOs. However, it is not uncommon to find NGOs promoting self-supply via wells.

Sustainable groundwater development

One assumption underlying this paper is that urban poor people’s direct dependence on groundwater remains, but that this is not fully appreciated in planning and decision-making at strategic city level, or in the international debate on groundwater, water access, and poverty alleviation. In part, this may be because the poor as a group do not have a voice. It may also be due to the fact that groundwater is a hidden resource, out of sight, underground, and in­sufficiently monitored; it is also not fully accounted for in the DHS and other statistics.

While increased use of groundwater at the urban level is predicted as well as promoted by several experts in the field today, the problems of sinking water tables and over-extraction from aquifers are reported in many parts of the world. This is pronounced where abstraction rates increase rapidly and changing precipitation patterns – some of which are linked to cli­mate change – affect aquifers’ recharge possibilities. 

Under-reporting water use from wells and springs, and especially the direct use of such sources, undermines the potential for informed research and debate on groundwater sus­tainability in the short as well as the long term. However, interpreting what ‘sustainable’ groundwater development may mean is a complex task since ecological, social as well as economic aspects should be taken into account. Determining how much water can be with­drawn from a given aquifer or aquifer system under or by a city before the abstra­tion/recharge rate is deemed unsustainable depends on a multitude of factors. These include local hydrogeology; the climate system and future changes to it; scale and purpose of the withdrawals; alternative water sources; the potential of accurate monitoring and modelling, and political will to enforce measures. The natural background levels of, for example, arse­nic, together with man-made contamination sources are important to take into account and deal with, as are the needs of the ecosystem.

The groundwater availability within a city can vary hugely because the aquifer conditions are rarely uniform. For instance, in Bangalore there is high dependence on groundwater and most wells are drilled to great depths in the characteristically low-yielding, weathered crystal­line bedrock. The conditions are, however, highly variable and hence unpredictable. Many attempts to drill wells fail, and existing boreholes and tubewells are routinely reported to dry up. At the same time, a large number of landowners have not noticed any significant lowering of the water table despite continuous pumping and selling of water for 15 years.

Differences between two neighbouring wells may be explained by highly localised fissures and fractures. Some of the variability may also depend on the fact that urban aquifers usually receive additional recharge via substantially leaking pipes and water mains.

Whether or not there are risks of sinking water tables and aquifer depletion is also deter­mined by what alternative water sources are available to different groups, both in socio­economic and in technical respects; and what quantities are being abstracted elsewhere from the same aquifer system, especially by large commercial abstractors, but also for irriga­tion. From the perspective of the generally water-deprived and under-served group of urban poor, temporary over-exploitation of aquifers may prove beneficial for development, health and well-being, provided that measures are taken to promote artificial recharge, rainwater harvesting, re-use, recycling, and in the long run perhaps reduced dependence on self-supply via wells.

Alarmist reports on water and groundwater scarcity and looming water crises seldom take all the above into account, and are, in many cases, not accompanied by consistent or easily as­sessable observations of the actual development. This does not serve a situation where growing urban populations require more water. Increased use of groundwater necessitates increased attention to the resource, based on a holistic view of availability, supply, demand and needs, and how the urban environment influences the dynamics of the water cycle.

Climate change and groundwater

The lack of data about groundwater resources also has implications for climate change re­search and policy-making. There are general uncertainties due to gaps in knowledge related to water including groundwater, which affect predictions of, for instance, altered precipitation patterns and how this may impact on aquifer recharge under a continuously changing cli­mate. These uncertainties are critical since the climate system and groundwater storage are fundamental, integrated parts of the hydrological cycle and, in turn, of all life on Earth.

Experienced climate researchers have suggested that global reliable surface water supplies are likely to decrease due to increased temporal variations of river flow, which are in turn caused by increased precipitation variability and decreased snow and ice storage. It may therefore be beneficial to take advantage of the storage capacity of aquifers, and plan for in­creased groundwater withdrawals for different purposes, including urban water supplies. Climate change in areas affected by reduced (or periods of reduced) river flow may cause an increase in the use of groundwater, both direct and indirect. In this case it is already appro­priate to take measures to enhance the recharge of local aquifers and to safeguard their quality.

Main messages and policy measures

Increased water availability is key to improved health. As a general message this paper wants to stress the importance of groundwater to poor urban dwellers who are often un­served and need to self-supply via wells. This direct dependence on groundwater needs to be acknowledged as a resource to be taken into account accurately in planning and inte­grated resource management at city level, and also in a larger, regional context.

This paper shows how lack of awareness of the importance of groundwater to poor urban dwellers, together with a lack of baseline data, obstructs a holistic view for planning and safeguarding groundwater resources in the short as well as the long term. Follow-up studies of urban self-supply are necessary, however. Local conditions must be understood, including an area’s hydrogeology, how its wells are monitored, along with government policies, institu­tional capacity, and interventions carried out by foreign aid programmes and NGOs. Any measures taken need to be contextualised; for instance, rainwater harvesting and other aqui­fer recharge-inducing steps may be pertinent in most city environments where large amounts of water are drawn from wells, but in a city such as Lusaka such measures are largely irrele­vant, due to the shallowness of its groundwater table for most parts of the year. Rather, it is more important to improve drainage possibilities in order to avoid floods during the rainy sea­son. In all urban areas, steps need to be taken to protect both aquifers and wells from con­tamination.

The following is a selection of measures integrating local well water resources into urban wa­ter resource management. Its focus is on improving the situation for urban poor people:

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Groundwater, self-supply and poor urban dwellers: A review with case studies of Bangalore and Lusaka Jenny T. Grönwall, Martin Mulenga, Gordon McGranahan

International Institute for Environment and Development website (IIED)

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