Water Harvesting in Sub-Saharan Africa

The results of the water harvesting technologies revisits carried out in the first phase of the WHaTeR project, together with contributions from other scientific sources, formed the basis for the publication of this book. Water Harvesting in Sub-Saharan Africa is the first spin-off of the WHaTeR project (

Edited by: William Critchley and John Gowing

Produced by: VU University Amsterdam in collaboration with the consortium partners of the EU-FP7 WHaTeR project.

Published by: Earthscan – Routledge, November 2012

Summary: Agriculture in Sub-Saharan Africa is constrained by highly variable rainfall, frequent drought and low water productivity. There is an urgent need, heightened by climate change, for appropriate technologies to address this problem through managing and increasing the quantity of water on farmers’ fields – water harvesting. This book defines water harvesting as a set of approaches which occupy an intermediate position along the water-management spectrum extending from in situ moisture conservation to irrigated agriculture. They generally comprise small-scale systems that induce, collect, store and make use of local surface runoff for agriculture. The authors review development experience and set out the state of the art of water harvesting for crop production and other benefits in Sub-Saharan Africa. This includes an assessment of water harvesting schemes that were initiated two or three decades ago when interest was stimulated by the droughts of the 1970s and 1980s. These provide lessons to promote sustainable development of dryland agriculture in the face of changing environmental conditions. Case studies from eight countries across Sub-Saharan Africa provide the evidence base. Each follows a similar format and is based on assessments conducted in collaboration with in-country partners, with a focus on attempts to promote adoption of water harvesting, both horizontally (spread) and vertically (institutionalization). Introductory cross-cutting chapters as well as an analytical conclusion are also included.

About the book: "This important and timely book addresses one of the most critical issues related to water and food security – enhancing the role of rainfed agriculture... The book addresses the vital question of how to make this happen, and thus provides critical information to practitioners and researchers. The authors argue that there is little time to waste; and while more research is certainly valuable, enough is known to go forward with confidence. That surely is an important message" – from the forward by David Molden, Director General ICIMOD and leader of the Comprehensive Assessment of Water Management in Agriculture.

Journal article


Authors: Ralph Lasage, Jeroen Aerts, Peter Verburg  and Alemu Seifu Sileshi

Journal: Mitigation and Adaptation Strategies for Global Change

The role of small scale sand dams in securing water supply under climate change in Ethiopia

Abstract: Community-based water storage in semi arid areas can help to adapt to climate change and mitigate household water shortages. Since little is known on the downstream effects of local water storage, this study employs a water balance model to perform a catchment scale assessment of upscaling local scale water storage in sand dams. The impacts of increasing water storage is evaluated under current climate conditions and future climate change scenarios. Survey information is used to estimate current and future water demand and assess the benefits derived from current sand dams in the Ethiopian study area. Using an indicator of the environmental flow concept, downstream hydrological impacts are simulated for different scenarios. Storage by 613 dams, supplying water to 555,000 people, has no impact on environmental flow downstream of the sand dams. Storage by 2190 dams leads to a modest increase in the number of months with low flow (4 to 9 %). Projected climate change leads to a larger increase in the number of low flow months of 0 to 29 %. Joint climate change and maximum storage scenarios cause an increase in low flow months from 4 to 50 %. Under the most extreme climate change projection 4.5 % of the wet season discharge is stored in sand dams. Because of the local benefits of improved water supply and the acceptable range of downstream impacts, sand dams appear to be a viable way for supplying drinking water in this catchment as well as in other semi-arid regions with similar conditions.

Keywords: Water harvesting . Adaptation . Climate change . Catchment model . Environmental flow . Storage . Sand dam

Journal article


Authors: Lauren Bulcock and Graham Jewitt

Journal: Physics and Chemistry of the Earth

Key physical characteristics used to assess water harvesting suitability

Abstract: Water harvesting (WH) techniques, which aim to increase water availability to crops, have long been used in arid and semi-arid areas to decrease the risk of reduced yields and crop failures due to dry spells. The landscape conditions dictate the type of WH system that can be implemented as well as the quantity and quality of water that will be collected. The measurement and understanding of how these landscape characteristics influence the hydrological function of WH systems is important and essential for further studies which seek to understand and enhance efficiency, extend uptake and model the impacts of WH within a catchment. However, commonly used guidelines often only prescribe optimal conditions for WH which results in many sites which may be suitable being over looked. Various statistical analyses was performed on 28 WH sites gathered from the available literature to try and identify whether the landscape conditions under which WH is currently taking place differs to the recommended guidelines. The results show that WH is taking place under a much broader range of conditions than those recommended by the guidelines. The recommendations for minimum and maximum slope in particular are too restrictive, with examples of successful WH taking place on slopes much steeper than the stipulated guidelines. A new set of guidelines are suggested, which take into account not only optimal conditions but also a range of suitable conditions on either side of the optimal range.

 Keywords: Water harvesting . Site characteristics . Upscaling . Statistical analysis . Site guidelines

Journal article


Authors: Marta G. Rivera-Ferre, Laura Pereira, Timothy Karpouzoglou, Kimberly Nicholas, Sheila Onzere, Wilma Waterlander, Fawzi Mahomoodally, Anton Vrieling,  Fola Babalola, Caroline C. Ummenhofer, Atul Dogra, Aline de Conti, Susanne Baldermann, Chijioke Evoh, Silke Bollmohr

Journal of Agriculture, Food Systems, and Community Development

A vision for transdisciplinarity in Future Earth: Perspectives from young researchers

Abstract: Meeting the demand for food, energy, and water as world population increases is a major goal for the food systems of the future. These future challenges, which are complex, multiscalar, and cross-sectoral in nature, require a food systems approach that recognizes the socio-ecological and socio-technical dimensions of food (Ericksen, 2008; Ingram, 2011; Rivera-Ferre, 2012). The United Nations’ Future Earth Program aims to provide a new platform for consolidating the knowledge required for societies to transition to global sustainability (Future Earth Transition Team, 2012). In this paper, we explore how Future Earth could become a vehicle for inspiring the production of new research ideas and collaborations for sustainably transforming the future food system. We do this on the basis of a synthesis of views from 28 young (below 40 years old) food system scientists, representing five continents. Their expertise comes from disciplines including food engineering, agronomy, ecology, geography, psychology, public health, food politics, nutritional science, political science, sociology and sustainability science. This paper begins with an outline of the institutional framework of Future Earth and how it might support innovative transdisciplinary research on food systems, and the position of young scientists within this framework. Secondly, we outline the key insights expressed by the young scientists during the Food Futures Conference in Villa Vigoni, Italy, in April 2013, including the core research questions raised during the meeting as well as some of the challenges involved in realizing their research ambitions within their professional spheres.

Keywords: Agri-food systems research . Future Earth .  Sustainability . Trandisciplinarity

Conference paper


Authors: Denyse Snelder, Douglas Gumbo, William Critchley and Sabina Di Prima

Conference: NASAC and KNAW conference on Water Management issues in Africa, Mauritius

Water Harvesting Technologies Revisited: Potentials for Innovations, Improvements and Upscaling in Sub-Saharan Africa

Abstract: One of the major challenges for Africa is to address poverty and hunger by promoting agricultural growth in general, and specifically by increasing productivity per unit area. Recent water management assessments reveal that farmed areas solely dependent on rainfall offer significant potential for improving agricultural productivity, and this is especially the case in Sub-Saharan Africa (SSA). At present, productivity is constrained by highly variable rainfall and frequent dry spells, making rainfed farming a risky undertaking. An estimated 70-85% of the rainfall on SSA dryland farms is lost through non-productive evaporation, surface runoff and drainage. Innovative Water Harvesting Technologies (WHTs) represent a key new intervention to strengthen productivity of rainfed agriculture. Traditionally, water harvesting technologies have been used throughout SSA. Yet these need to evolve with the times, taking into account environmental, economic and demographic change. WHaTeR, an EC-funded project launched in January 2011, has been set up to contribute to the development of WHTs that strengthen rainfed agriculture, and thus rural livelihoods, food production, and food security in SSA. This paper presents the first results of the “revisit” study and situation analysis of selected water harvesting technology sites, comparing the “past and present” conditions, in a number of countries in SSA. The abstract uses the Zimbabwe revisit study of standard graded contours and dead level contours, as an example.   

Keywords: Rainwater harvesting . Dead level contour  . Standard graded contour . Zimbabwe 

Conference paper


Authors: Maimbo Malesu, Jan de Leeuw and Alex Oduor

Conference: International Rainwater Catchment Systems Association (IRCSA), China

Water Harvesting Experiences from the SearNet (2003-2012)

Abstract: The main objective of this paper is to share experiences of the Southern and Eastern Africa Rainwater Network (SearNet) on water harvesting. SearNet argues that governments in Sub-Saharan Africa (SSA) have not adequately considered rainwater as a viable water supply option for domestic, industrial, agricultural and environmental use. Consequently planners and engineers only consider blue water or one third of rainwater (in the rivers, lakes, dams and groundwater) leaving out productive rainwater that could boost water supply and food production in the region. The paper therefore challenges the unique focus of government investments on large dams and boreholes or conventional water supply systems due to their limited impact on rural populations. In order to address these concerns, ICRAF has been hosting the SearNet, a regional network that focuses on reviving the ancient practice of water harvesting. The paper shares lessons drawn from policy research and evaluation, awareness creation and networking, building of national networks and assessment of promising water harvesting technologies in Sub-Saharan Africa. The paper concludes that diligent land and water management is necessary for yielding the highest benefits from rainwater. There is need to continuously educate people so as to promote integrated management of land and water resources. In addition to enabling policies and institutions, there is a need for ample budgetary support to increase adoption of the technology.

Keywords: Rainwater Harvesting . Blue water . Water scarcity . Policy . Water harvesting techniques

Last modified: Monday, 5 October 2015, 1:38 PM