- United Kingdom
Roger Calow
Overseas development institute, Water Policy, Department Member
It is predicted that climate change will result in big changes to the global distribution of rainfall, causing drought and desertification in some regions and floods in others. Already there are signs of such changes occurring, with... more
It is predicted that climate change will result in big changes to the global distribution of rainfall, causing drought and desertification in some regions and floods in others. Already there are signs of such changes occurring, with particularly serious consequences for poorer countries. The need for international cooperation in managing the effects of climate change, and other influences on the hydrological cycle, is becoming urgent. Future wars may well be fought over water. This book is part of a series focusing on key issues in environmental science and technology. Focusing on the sustainability of water supplies to the growing populations throughout the world, this volume consists of articles contributed by a group of experts drawn from around the globe. Issues covered include: policy making in the European Union; rural water supplies in Africa; chemical monitoring and analytical methods; water use in agriculture; social justice in supplying water; potable water recycling, and ...
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Drought is a recurring event in Africa. The recent drought, affecting large swathes of eastern and southern Africa, is not exceptional. For many, drought is associated with food insecurity: rains fail; crops wither; food supplies dwindle;... more
Drought is a recurring event in Africa. The recent drought, affecting large swathes of eastern and southern Africa, is not exceptional. For many, drought is associated with food insecurity: rains fail; crops wither; food supplies dwindle; entitlement to food declines and people go hungry. The response, on the part of government and donors, is typically food aid ‘to save lives’. Yet food insecurity is not the only concern during drought, and is not an isolated concern. One of the principal aims of this report – a synthesis of over four years’ research – is to show how livelihoods are affected by declining access to food and water, with access to both linked in a number of important ways. Implications for policy, to protect livelihoods before lives are threatened, are highlighted. The report begins with a description of the evolution and scope of the project ‘Groundwater drought early warning for vulnerable areas’, and the rationale for working in the Amhara Region of Ethiopia. Chapte...
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During drought, groundwater is often relied on to provide secure drinking water, particularly in rural Africa where other options are limited. However, the technology chosen to access groundwater significantly affects local water... more
During drought, groundwater is often relied on to provide secure drinking water, particularly in rural Africa where other options are limited. However, the technology chosen to access groundwater significantly affects local water security. Here we examine the performance of springs, hand-dug-wells and boreholes in northern Ethiopia through direct high frequency monitoring of water-levels (n = 19) and water quality (n = 48) over an 18 month period and gathering information on community impacts of declining water access during the El Niño 2015/2016 drought. We found that shallow boreholes equipped with handpumps were the most reliable water supply, recovering within hours to daily abstraction throughout all conditions. Recovery and performance of most hand-dug-wells and springs declined significantly throughout the extended dry season, although in specific aquifer conditions they were reliable. All sources types had negligible measured contamination from Thermo-tolerant Coliforms thro...
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A large number of groundwater projects use geophysics to help avoid costly events such as a failed borehole. Yet what are the methods used and how much guarantee of water can geophysics offer to a water project?
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The article details the development and uses of the water poverty index (WPI). The index was developed as a holistic tool to measure water stress at the household and community levels, designed to aid national decision makers, at... more
The article details the development and uses of the water poverty index (WPI). The index was developed as a holistic tool to measure water stress at the household and community levels, designed to aid national decision makers, at community and central government level, as ...
Research Interests: Environmental Science, Economics, Development Studies, Water, Natural Resources, and 15 morePoverty, Water Availability, Sri Lanka, Environmental Sustainability, Multidisciplinary, Water Management, Environmental Sciences, South Africa, Indicators, Indexation, Decision Maker, Food Products, Environment, Pilot project, and National Survey
Much of southern and eastern Africa is semi-arid and heavily groundwater dependent. Borehole drilling commenced over a hundred years ago with magnetic and electrical resistivity surveys for borehole siting being introduced from 1936.... more
Much of southern and eastern Africa is semi-arid and heavily groundwater dependent. Borehole drilling commenced over a hundred years ago with magnetic and electrical resistivity surveys for borehole siting being introduced from 1936. Formalised training of hydrogeologists led in the 1970s to an almost standard approach to hydrogeological investigation and a period of stability followed, during which some major investigations
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NERC has developed NORA to enable users to access research outputs wholly or partially funded by NERC. Copyright and other rights for material on this site are retained by the authors and/or other rights owners. Users should read the... more
NERC has developed NORA to enable users to access research outputs wholly or partially funded by NERC. Copyright and other rights for material on this site are retained by the authors and/or other rights owners. Users should read the terms and conditions of use of this ...
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This report marks the end of the short inception phase of the DFID KaR project (R8162) increasing the uptake of techniques which increase the success and sustainability of wells and boreholes. The project has been designed to contribute... more
This report marks the end of the short inception phase of the DFID KaR project (R8162) increasing the uptake of techniques which increase the success and sustainability of wells and boreholes. The project has been designed to contribute to two of DFID’s themes for the water sector: Improved water and sanitation (W4) through increased uptake of research (X3). Much of the inception phase has comprised consultation through building an email network, organising an inception workshop and establishing a website. An email network has been established for the project comprising over 200 water professionals and scientists with an interest in rural water supplies. They come from 29 different countries with 18% from government, 23% from NGOs, 20% from the private sector, 31% researchers and the rest from donors and UN agencies. Approximately 35% of the network (73 people) have contributed to the project either through email or attending one of the workshops. Two workshops were held at the Wate...
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This technical brief is aimed at sharing the learning and approaches developed by the UPGro Hidden Crisis Research Project to look at how the functionality and performance levels of boreholes equipped with handpumps (HPBs), can be... more
This technical brief is aimed at sharing the learning and approaches developed by the UPGro Hidden Crisis Research Project to look at how the functionality and performance levels of boreholes equipped with handpumps (HPBs), can be assessed using a common set of definitions and methods. A tiered approach to defining and measuring functionality is found to be useful to examining functionality for different scales and purposes of monitoring. This report is aimed at national and regional actors involved in the provision and monitoring of rural water supply functionality. The brief sets out the tiered functionality definitions, and accompanying survey methods, which were developed by the project and have been applied in functionality surveys across Ethiopia, Uganda and Malawi [5-7]. The brief provides a summary of: • The tiered approach to defining and measuring the functionality and performance levels of boreholes equipped with handpumps (HPBs). • A series of survey methods which were f...
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Climate change represents the most significant challenge of the twenty-first century and poses risks to water and sanitation services. Concerns for water supply include damage to infrastructure from flooding, loss of water sources due to... more
Climate change represents the most significant challenge of the twenty-first century and poses risks to water and sanitation services. Concerns for water supply include damage to infrastructure from flooding, loss of water sources due to declining rainfall and increasing demand, and changes in the water quality of water sources and within distribution of water. Sanitation concerns include damage and loss of services from floods and reduced carrying capacity of waters receiving wastewater. Key actions to reduce climate risks include the integration of measures of climate resilience into water safety plans, as well as improved accounting and management of water resources. Policy prescriptions on technologies for service delivery and changes in management models offer potential to reduce risks, particularly in low-income settings. Water and sanitation services contribute to greenhouse gas emissions. Choice of wastewater treatment technologies, improved pumping efficiency, use of renewa...
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This research report is an output of the project Community Management of Groundwater Resources in Rural India (Comman), funded by the UK’s Department for International Development (DFID) under its Knowledge and Research (KaR) programme.... more
This research report is an output of the project Community Management of Groundwater Resources in Rural India (Comman), funded by the UK’s Department for International Development (DFID) under its Knowledge and Research (KaR) programme. The primary aim of the project has been to assess the feasibility of applying local, user-based approaches to groundwater management as a means of mitigating, or avoiding, groundwater overdraft problems in rural areas. Concern over the sustainability of groundwater systems and groundwater-dependent livelihoods has grown in recent years. The project focus on community-level initiatives as a response to such concern is timely given the emphasis now placed, internationally, on the role of communities in natural resource governance. This Research Report report draws together six of the background papers prepared during the project on different aspects of groundwater resources management in India. The report is split into two sections. The first section looks at the problem of groundwater overdraft from different perspectives – physical controls and symptoms, socio-economic impacts, and from the wider context of livelihood transition and groundwater dependency. The second section addresses the management challenge, drawing distinctions between planned (or conventional) management, and self-initiated user-group management.
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This study evaluates the comparative advantages of public-private partnerships (PPPs) and (public-public partnerships) PuPs in urban water services. Based on literature analysis and case studies, past performance of PPPs and PuPs is... more
This study evaluates the comparative advantages of public-private partnerships (PPPs) and (public-public partnerships) PuPs in urban water services. Based on literature analysis and case studies, past performance of PPPs and PuPs is reviewed against several criteria. Lessons are then identified regarding the barriers and enablers which determine the success of partnerships, and the kind of support donors could usefully provide. The study concludes that while the main determinant of performance is not public or private management but policy, institutions, finance and regulation, there are notable differences between what PPPs and PuPs can offer. In the right circumstances the private sector can improve in efficiency and management, but at high costs. PuPs generally have lower costs and greater focus on capacity building and equity, and have the potential to support more holistic approaches to urban services and the water cycle. Partnerships with local actors can also improve services...
Data from a highland to lowland transect in the Oromia Region of eastern Ethiopia show that household water use is minimal, regardless of presence of improved sources, and variations in use are driven by interactions of poverty and... more
Data from a highland to lowland transect in the Oromia Region of eastern Ethiopia show that household water use is minimal, regardless of presence of improved sources, and variations in use are driven by interactions of poverty and rainfall variability. In the dry season, when many sources fail, use for hygiene drops perilously, particularly among poor households, as collection times rise and coincide with high demands for wage labour. Providing sufficient water for livestock is also a struggle for poor agropastoral households. Poorer households use less water because they have less labour for water collection and fewer storage and transport assets. Labour shortages also make nearer, unsafe sources preferable to more distant protected schemes. The health and livelihood benefits of improved water access depend on continuous use of sufficient safe water, by all, but we have limited knowledge of actual water use patterns. This paper aims to help address this gap, and documents intra-community inequities and seasonal variations in water access. These are not captured in coverage statistics, but are likely to occur wherever pronounced climate variability, inadequate infrastructure and severe poverty coincide.
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Groundwater is an important source of water supply for many cities being both relatively cheap to exploit and generally good quality. However in many developing countries the subsurface from which the water is obtained is also widely used... more
Groundwater is an important source of water supply for many cities being both relatively cheap to exploit and generally good quality. However in many developing countries the subsurface from which the water is obtained is also widely used for the disposal of wastewaters. As a consequence shallow groundwater is frequently polluted. Abstraction from deeper aquifers can reverse vertical water level gradients and induce substantial leakage from shallow layers. Currently the deeper groundwaters beneath cities are usually of high quality being derived from recharge which occurred many decades if not centuries previously. The security of this valuable resource is of major concern. Results from this project suggest that leakage from beneath cities makes a substantial contribution to recharge to these deeper aquifers although travel times from shallow are typically 10-40 years. These timescales ensure that only the most mobile and persistent contaminants are likely to reach these deeper aquifers. For these reasons, nitrogen, chloride and the chlorinated solvents represent the contaminants of most concern. Secondary quality changes caused by a change in the redox potential of these groundwaters can have a major and possibly more serious impact producing increases in iron and manganese groundwater concentrations. In addition arsenic has been identified as a quality concern. A simple methodology for assessing risk based on the importance of urban derived leakage has been developed.
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Africa lags behind the rest of the world in achieving international targets for access to safe water and sanitation services, with more than 300 million people without access to an improved water supply and 600 million without adequate... more
Africa lags behind the rest of the world in achieving international targets for access to safe water and sanitation services, with more than 300 million people without access to an improved water supply and 600 million without adequate sanitation. Therefore, there is renewed emphasis to scale up programmes to increase coverage. Improved water supplies generally rely on the development of groundwater; and sanitation programmes depend on the ability of subsurface to assimilate waste. However, despite the important role of groundwater, hydrogeology and hydrogeologists are rarely given due consideration in planning, implementing and appraising these programmes. Here we discuss what hydrogeological science can contribute to water supply and sanitation (WASH) programmes, illustrated using examples from several programmes across Africa. We propose a framework to help prioritise the involvement of hydrogeologists and the role of groundwater science in improving WASH and making interventions more cost effective and sustainable. The same level of hydrogeological expertise is not required in all areas, but should be targeted to where the impact will be greatest. However, to make the decision on the level of expertise required for a programme requires the contribution from a hydrogeologist early in the planning cycle. The important role of hydrogeological and hydrochemical mapping and resource evaluation in planning programmes is discussed using examples from Nigeria and Ethiopia. Different methods for groundwater exploration are discussed using a recent programme in northern Ghana. The role of hydrogeologists in overseeing construction is illustrated from a world bank project in Ethiopia to assess levels of corruption in rural water supply. Hydrogeological science also has a crucial role in researching future opportunities and issues as a result of climate change, population growth, and food insecurity. Hydrogeologists clearly have much to offer WASH programmes. To be most effective hydrogeology should be communicated effectively and in a manner that is easily integrated into existing programmes. Hydrogeologists should also accept that there are some areas where employing modern hydrogeological techniques will not be cost effective and concentrate on the areas where they can best add value.
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ABSTRACT In order to supply water for growing industrial needs in Ordos City, Hangjin Irrigation District on the south bank of the Yellow River, Inner Mongolia has traded some of its irrigation water to downstream factories. The trading... more
ABSTRACT In order to supply water for growing industrial needs in Ordos City, Hangjin Irrigation District on the south bank of the Yellow River, Inner Mongolia has traded some of its irrigation water to downstream factories. The trading is termed “irrigation water-saving supported by industrial investment, with saved water traded to industry”. At the same time, Hangjin Irrigation District has conducted a comprehensive reform of irrigation water management focused on water rights. This paper describes the current status of water management in the district, outlines some of the problems water trading has produced, and presents a framework for further water rights reform focused on rights allocation, the granting of volumetrically-capped water certificates and tickets, water use planning and monitoring, and the responsibilities of water user associations in ensuring that individual farmers receive fair allocations. The paper then summarizes key recommendations of relevance to Hangjin and other irrigation districts in China.
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Water is essential for all life is and occurs in various natural stores of the Earth’s hydrological cycle, including lakes, wetlands, rivers and aquifers. However, natural spatial and temporal variability in climate means that water of... more
Water is essential for all life is and occurs in various natural stores of the Earth’s hydrological cycle, including lakes, wetlands, rivers and aquifers. However, natural spatial and temporal variability in climate means that water of sufficient quantity and adequate quality is not always available for human needs (drinking, growing crops, generating power, supporting industry or maintaining ecosystem services, such