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| | = Background = | | = Background = |
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| − | Rainwater harvesting refers to a wide range of different techniques for accumulation, storage and provision of rainwater. Uses of collected water include provision of drinking water, water for livestock and irrigation, diversion of run-off water for infiltration in water scarce cropping areas, and refill of aquifers (groundwater recharge).<ref name="ICARDA">ICARDA/Oweis, T., Prinz, D. & Hachum, A. (2001): Water Harvesting Indigenous Knowledge for the Future of the Drier Environments, ICARDA, Aleppo, Syria. http://temp.icarda.org/wli/pdfs/Books/Water_harvest_En.pdf [Access 2012-11-18]</ref> Rainwater harvesting is an ancient practice, and has been developed in areas where rainfall is not sufficient to support crop production or is too variable to guarantee a harvest, or where drinking water sources are scarce. Around 80% of crop land worldwide is rainfed. Nowadays, water resources in dry areas are under even more pressure due to population growth, environmental degradation and climate change.<ref name="ICARDA">ICARDA/Oweis, T., Prinz, D. & Hachum, A. (2001): Water Harvesting Indigenous Knowledge for the Future of the Drier Environments, ICARDA, Aleppo, Syria. http://temp.icarda.org/wli/pdfs/Books/Water_harvest_En.pdf [Access 2012-11-18]</ref><br/>Climate change refers to the increased occurrence of droughts and varying rainfall patterns. Rainwater harvesting can be used as a low cost adaptation mechanism at the farm level for increasing soil moisture, reducing soil temperature, and recharging groundwater and other water resources. Around a third of the African continent has the potential for rainwater harvesting; in the past few years, many programmes have been launched for promoting such measures throughout Africa.<ref name="afdb">AfDB (2012): African Water Facility Grant Helps Kenyan Pastoralists Build Resilience to Droughts, Climate Change. Press release 09/08/2012. http://www.afdb.org/en/news-and-events/article/african-water-facility-grant-helps-kenyan-pastoralists-build-resilience-to-droughts-climate-change-9597/ [Access 2012-10-08]</ref> | + | Rainwater harvesting refers to a wide range of different techniques for accumulation, storage and provision of rainwater. Uses of collected water include provision of drinking water, water for livestock and irrigation, diversion of run-off water for infiltration in water scarce cropping areas, and refill of aquifers (groundwater recharge).<ref name="ICARDA">ICARDA/Oweis, T., Prinz, D. & Hachum, A. (2001): Water Harvesting Indigenous Knowledge for the Future of the Drier Environments, ICARDA, Aleppo, Syria. http://temp.icarda.org/wli/pdfs/Books/Water_harvest_En.pdf [Access 2012-11-18]</ref> Rainwater harvesting is an ancient practice, and has been developed in areas where rainfall is not sufficient to support crop production or is too variable to guarantee a harvest, or where drinking water sources are scarce. Around 80% of crop land worldwide is rainfed. Nowadays, water resources in [[Dryland farming|dry areas]] are under even more pressure due to population growth, environmental degradation and climate change.<ref name="ICARDA">ICARDA/Oweis, T., Prinz, D. & Hachum, A. (2001): Water Harvesting Indigenous Knowledge for the Future of the Drier Environments, ICARDA, Aleppo, Syria. http://temp.icarda.org/wli/pdfs/Books/Water_harvest_En.pdf [Access 2012-11-18]</ref><br/>Climate change refers to the increased occurrence of droughts and varying rainfall patterns. Rainwater harvesting can be used as a low cost adaptation mechanism at the farm level for increasing soil moisture, reducing soil temperature, and recharging groundwater and other water resources. Around a third of the African continent has the potential for rainwater harvesting; in the past few years, many programmes have been launched for promoting such measures throughout Africa.<ref name="afdb">AfDB (2012): African Water Facility Grant Helps Kenyan Pastoralists Build Resilience to Droughts, Climate Change. Press release 09/08/2012. http://www.afdb.org/en/news-and-events/article/african-water-facility-grant-helps-kenyan-pastoralists-build-resilience-to-droughts-climate-change-9597/ [Access 2012-10-08]</ref> |
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| | [[File:Rainwater harvesting systems.jpg|border|center|265px|Rainwater harvesting systems, mode of storage and use of water|alt=Rainwater harvesting systems, mode of storage and use of water]] | | [[File:Rainwater harvesting systems.jpg|border|center|265px|Rainwater harvesting systems, mode of storage and use of water|alt=Rainwater harvesting systems, mode of storage and use of water]] |
| − | <p style="text-align: center;">Figure 1: Rainwater harvesting systems, mode of storage and use of water<ref name="UNEP">UNEP (2009): Rainwater harvesting: a lifeline for human well-being http://www.unep.org/publications/search/pub_details_s.asp?ID=4024 [Access 2012-11-18]</ref></p> | + | <p style="text-align: center">Figure 1: Rainwater harvesting systems, mode of storage and use of water<ref name="UNEP">UNEP (2009): Rainwater harvesting: a lifeline for human well-being http://www.unep.org/publications/search/pub_details_s.asp?ID=4024 [Access 2012-11-18]</ref></p> |
| | [[File:Rainwater harvesting classification ICARDA 2001.jpg|center|227px|Classification of rainwater harvesting systems by ICARDA|alt=Classification of rainwater harvesting systems by ICARDA]] | | [[File:Rainwater harvesting classification ICARDA 2001.jpg|center|227px|Classification of rainwater harvesting systems by ICARDA|alt=Classification of rainwater harvesting systems by ICARDA]] |
| − | <p style="text-align: center;">Figure 2: Classification of rainwater harvesting systems by ICARDA<ref name="ICARDA">ICARDA/Oweis, T., Prinz, D. & Hachum, A. (2001): Water Harvesting Indigenous Knowledge for the Future of the Drier Environments, ICARDA, Aleppo, Syria. http://temp.icarda.org/wli/pdfs/Books/Water_harvest_En.pdf [Access 2012-11-18]</ref></p> | + | <p style="text-align: center">Figure 2: Classification of rainwater harvesting systems by ICARDA<ref name="ICARDA">ICARDA/Oweis, T., Prinz, D. & Hachum, A. (2001): Water Harvesting Indigenous Knowledge for the Future of the Drier Environments, ICARDA, Aleppo, Syria. http://temp.icarda.org/wli/pdfs/Books/Water_harvest_En.pdf [Access 2012-11-18]</ref></p> |
| | = In situ rainwater harvesting = | | = In situ rainwater harvesting = |
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| | In situ rainwater harvesting systems are based on changing soil and water management techniques, with the aim to improve infiltration, water holding capacity and fertility of the soil, and to counter soil erosion. Via various types of barriers, rainwater runoff in sloping fields can be captured in the field and stored in the soil for immediate use by the crop. Capture and storage areas are within a small distance. Rainwater harvesting is basically about enhancing the water intake at | | In situ rainwater harvesting systems are based on changing soil and water management techniques, with the aim to improve infiltration, water holding capacity and fertility of the soil, and to counter soil erosion. Via various types of barriers, rainwater runoff in sloping fields can be captured in the field and stored in the soil for immediate use by the crop. Capture and storage areas are within a small distance. Rainwater harvesting is basically about enhancing the water intake at |
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| | *the soil surface (infiltration through diverting surface runoff) | | *the soil surface (infiltration through diverting surface runoff) |
| | *the rooting zone (water uptake by plants) | | *the rooting zone (water uptake by plants) |
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| | [[File:Semi-circular bund with description in Sahel 2012 Wegner.jpg|center|222px|In situ rainwater harvesting with semi-circular bunds in Sahel. Water is captured behind the earthen embankment (Photo: Wegener, M.)|alt=In situ rainwater harvesting with semi-circular bunds in Sahel. Water is captured behind the earthen embankment (Photo: Wegener, M.)]] | | [[File:Semi-circular bund with description in Sahel 2012 Wegner.jpg|center|222px|In situ rainwater harvesting with semi-circular bunds in Sahel. Water is captured behind the earthen embankment (Photo: Wegener, M.)|alt=In situ rainwater harvesting with semi-circular bunds in Sahel. Water is captured behind the earthen embankment (Photo: Wegener, M.)]] |
| − | <p style="text-align: center;">Figure 3: In situ rainwater harvesting with semi-circular bunds in Sahel. Water is captured behind the earthen embankment (Photo: Wegener, M.)</p> | + | <p style="text-align: center">Figure 3: In situ rainwater harvesting with semi-circular bunds in Sahel. Water is captured behind the earthen embankment (Photo: Wegener, M.)</p> |
| | == Ex situ rainwater harvesting == | | == Ex situ rainwater harvesting == |
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| | [[File:Ex situ rainwater harvesting atajado in Bolivia.png|center|247px|Figure 4: Ex situ rainwater harvesting with small-scale water reservoir (atajado) in the Bolivian Andes with sedimentation basin at the inlet (Photo: Picht, H.J.)|alt=Figure 4: Ex situ rainwater harvesting with small-scale water reservoir (atajado) in the Bolivian Andes with sedimentation basin at the inlet (Photo: Picht, H.J.)]] | | [[File:Ex situ rainwater harvesting atajado in Bolivia.png|center|247px|Figure 4: Ex situ rainwater harvesting with small-scale water reservoir (atajado) in the Bolivian Andes with sedimentation basin at the inlet (Photo: Picht, H.J.)|alt=Figure 4: Ex situ rainwater harvesting with small-scale water reservoir (atajado) in the Bolivian Andes with sedimentation basin at the inlet (Photo: Picht, H.J.)]] |
| − | <p style="text-align: center;">Figure 4: Ex situ rainwater harvesting with small-scale water reservoir (atajado) in the Bolivian Andes with sedimentation basin at the inlet (Photo: Picht, H.J.)</p> | + | <p style="text-align: center">Figure 4: Ex situ rainwater harvesting with small-scale water reservoir (atajado) in the Bolivian Andes with sedimentation basin at the inlet (Photo: Picht, H.J.)</p> |
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| | == Overview of rainwater harvesting technologies == | | == Overview of rainwater harvesting technologies == |
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| | [[File:Table 1, Examples of in situ rainwater harvesting systems with description.jpg|left|62px|alt=Table 1, Examples of in situ rainwater harvesting systems with description.jpg]] | | [[File:Table 1, Examples of in situ rainwater harvesting systems with description.jpg|left|62px|alt=Table 1, Examples of in situ rainwater harvesting systems with description.jpg]] |
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| − | Table 1: Examples of rainwater harvesting systems implemented in countries of sub-Saharan Africa, with overview on technique, climate change adaptation potential, effects, success factors and costs. <ref name="GIZ">GIZ (2006): Zanjas de infiltración, La Paz, Boliva. http://proagro-bolivia.org/files/CARTILLA_4_ZANJAS_inflitracion.pdf [Access 2012-10-08]</ref><ref name="GIZa">GIZ/Goetter, J. (2010a): Adaptación al Cambio Climático: Cosecha de Agua de Lluvia con “Atajados” en Bolivia, Lima, Peru. http://www.riesgoycambioclimatico.org/documentos/ACC_con_CA.pdf [Access 2012-10-08]</ref><ref name="GIZb">GIZ/Goetter, J. (2010b): El Cambio Climático en el areá rural del Sur de Cochabamba y Norte de Potosí (Bolivia); La Paz, Bolivia. http://www.riesgoycambioclimatico.org/biblioteca/archivos/DC1115.pdf [Access 2012-10-08]</ref><ref name="GIZc">GIZ/Goetter, J. (2010c): Water harvesting: A promising climate change adaptation option for traditional Andean agriculture in Bolivia, -in: Rural Development News 2/2010. http://www.agridea-international.ch/fileadmin/10_International/PDF/RDN/RDN_2010/9_Water_harvesting.pdf [Access 2012-10-08</ref><ref name="GIZ12a">GIZ (2012a): Good Practices in Soil and Water Conservation, Eschborn. http://www.giz.de/Themen/en/SID-F89EB9ED-AC839C2B/36546.htm [Access 2012-10-08]</ref> | + | Table 1: Examples of rainwater harvesting systems implemented in countries of sub-Saharan Africa, with overview on technique, climate change adaptation potential, effects, success factors and costs. <ref name="GIZ">GIZ (2006): Zanjas de infiltración, La Paz, Boliva. http://proagro-bolivia.org/files/CARTILLA_4_ZANJAS_inflitracion.pdf [Access 2012-10-08]</ref><ref name="GIZa">GIZ/Goetter, J. (2010a): Adaptación al Cambio Climático: Cosecha de Agua de Lluvia con “Atajados” en Bolivia, Lima, Peru. http://www.riesgoycambioclimatico.org/documentos/ACC_con_CA.pdf [Access 2012-10-08]</ref><ref name="GIZb">GIZ/Goetter, J. (2010b): El Cambio Climático en el areá rural del Sur de Cochabamba y Norte de Potosí (Bolivia); La Paz, Bolivia. http://www.riesgoycambioclimatico.org/biblioteca/archivos/DC1115.pdf [Access 2012-10-08]</ref><ref name="GIZc">GIZ/Goetter, J. (2010c): Water harvesting: A promising climate change adaptation option for traditional Andean agriculture in Bolivia, -in: Rural Development News 2/2010. http://www.agridea-international.ch/fileadmin/10_International/PDF/RDN/RDN_2010/9_Water_harvesting.pdf [Access 2012-10-08</ref><ref name="GIZ12a">GIZ (2012a): Good Practices in Soil and Water Conservation, Eschborn. http://www.giz.de/Themen/de/dokumente/giz2012-en-soil-water-conservation.pdf</ref> |
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| | [[File:Table 2, Example of ex situ rainwater harvesting system with description.jpg|left|64px|alt=Table 2, Example of ex situ rainwater harvesting system with description.jpg]] | | [[File:Table 2, Example of ex situ rainwater harvesting system with description.jpg|left|64px|alt=Table 2, Example of ex situ rainwater harvesting system with description.jpg]] |
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| | Table 2: Small-scale basins as an example of an ex situ rainwater harvesting system, with overview on technique, climate change adaptation potential, effects, success factors and costs.<ref name="GIZ">GIZ (2006): Zanjas de infiltración, La Paz, Boliva. http://proagro-bolivia.org/files/CARTILLA_4_ZANJAS_inflitracion.pdf [Access 2012-10-08]</ref><ref name="GIZa">GIZ/Goetter, J. (2010a): Adaptación al Cambio Climático: Cosecha de Agua de Lluvia con “Atajados” en Bolivia, Lima, Peru. http://www.riesgoycambioclimatico.org/documentos/ACC_con_CA.pdf [Access 2012-10-08]</ref><ref name="GIZb">GIZ/Goetter, J. (2010b): El Cambio Climático en el areá rural del Sur de Cochabamba y Norte de Potosí (Bolivia); La Paz, Bolivia. http://www.riesgoycambioclimatico.org/biblioteca/archivos/DC1115.pdf [Access 2012-10-08]</ref><ref name="GIZc">GIZ/Goetter, J. (2010c): Water harvesting: A promising climate change adaptation option for traditional Andean agriculture in Bolivia, -in: Rural Development News 2/2010. http://www.agridea-international.ch/fileadmin/10_International/PDF/RDN/RDN_2010/9_Water_harvesting.pdf [Access 2012-10-08]</ref> | | Table 2: Small-scale basins as an example of an ex situ rainwater harvesting system, with overview on technique, climate change adaptation potential, effects, success factors and costs.<ref name="GIZ">GIZ (2006): Zanjas de infiltración, La Paz, Boliva. http://proagro-bolivia.org/files/CARTILLA_4_ZANJAS_inflitracion.pdf [Access 2012-10-08]</ref><ref name="GIZa">GIZ/Goetter, J. (2010a): Adaptación al Cambio Climático: Cosecha de Agua de Lluvia con “Atajados” en Bolivia, Lima, Peru. http://www.riesgoycambioclimatico.org/documentos/ACC_con_CA.pdf [Access 2012-10-08]</ref><ref name="GIZb">GIZ/Goetter, J. (2010b): El Cambio Climático en el areá rural del Sur de Cochabamba y Norte de Potosí (Bolivia); La Paz, Bolivia. http://www.riesgoycambioclimatico.org/biblioteca/archivos/DC1115.pdf [Access 2012-10-08]</ref><ref name="GIZc">GIZ/Goetter, J. (2010c): Water harvesting: A promising climate change adaptation option for traditional Andean agriculture in Bolivia, -in: Rural Development News 2/2010. http://www.agridea-international.ch/fileadmin/10_International/PDF/RDN/RDN_2010/9_Water_harvesting.pdf [Access 2012-10-08]</ref> |
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| | = Benefits of rainwater harvesting systems = | | = Benefits of rainwater harvesting systems = |
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| | [[File:Benefits of rainwater harvsting systems.jpg|center|394px|Some potential benefits on different aspects of rainwater harvesting systems in rural areas|alt=Some potential benefits on different aspects of rainwater harvesting systems in rural areas]] | | [[File:Benefits of rainwater harvsting systems.jpg|center|394px|Some potential benefits on different aspects of rainwater harvesting systems in rural areas|alt=Some potential benefits on different aspects of rainwater harvesting systems in rural areas]] |
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| − | Table 3: Some potential benefits on different aspects of rainwater harvesting systems in rural areas.<ref name="FAO">FAO/Critchley, W., Siegert, K. & Chapman, C. (1991): Water Harvesting. http://www.fao.org/docrep/U3160E/u3160e00.htm#Contents [Access 2012-10-08]</ref><ref name="GIZ12a">GIZ (2012a): Good Practices in Soil and Water Conservation, Eschborn. http://www.giz.de/Themen/en/SID-F89EB9ED-AC839C2B/36546.htm [Access 2012-10-08]</ref><ref name="Prinz">Prinz, D., (1996). Water Harvesting: Past and Future. In: Pereira, L. S. (ed.), Sustainability of Irrigated Agriculture. Proceedings, NATO Advanced Research Workshop, Vimeiro, 21- 26.03.1994, Balkema, Rotterdam.</ref><ref name="UNEP">UNEP (2009): Rainwater harvesting: a lifeline for human well-being http://www.unep.org/publications/search/pub_details_s.asp?ID=4024 [Access 2012-11-18]</ref><ref name="GIZ (2011a)">GIZ (2011a): Bringing the UNCCD down to earth. Bonn. http://www.desertifikation.de/fileadmin/user_upload/downloads/2011/giz2011-en-Lessons-learned-Bringing-the-UNCCD-down-to-earth.pdf [Access 2012-10-08].</ref> | + | Table 3: Some potential benefits on different aspects of rainwater harvesting systems in rural areas.<ref name="FAO">FAO/Critchley, W., Siegert, K. & Chapman, C. (1991): Water Harvesting. http://www.fao.org/docrep/U3160E/u3160e00.htm#Contents [Access 2012-10-08]</ref><ref name="GIZ12a">GIZ (2012a): Good Practices in Soil and Water Conservation, Eschborn. http://www.giz.de/Themen/de/dokumente/giz2012-en-soil-water-conservation.pdf</ref><ref name="Prinz">Prinz, D., (1996). Water Harvesting: Past and Future. In: Pereira, L. S. (ed.), Sustainability of Irrigated Agriculture. Proceedings, NATO Advanced Research Workshop, Vimeiro, 21- 26.03.1994, Balkema, Rotterdam.</ref><ref name="UNEP">UNEP (2009): Rainwater harvesting: a lifeline for human well-being http://www.unep.org/publications/search/pub_details_s.asp?ID=4024 [Access 2012-11-18]</ref><ref name="GIZ (2011a)">GIZ (2011a): Bringing the UNCCD down to earth. Bonn. http://www.desertifikation.de/fileadmin/user_upload/downloads/2011/giz2011-en-Lessons-learned-Bringing-the-UNCCD-down-to-earth.pdf [Access 2012-10-08].</ref> |
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| | = Limitations and challenges of rainwater harvesting systems = | | = Limitations and challenges of rainwater harvesting systems = |
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| | [[File:Table 4, Limiting factors of rainwater harvesting systems development cooperation.jpg|left|171px|alt=Table 4, Limiting factors of rainwater harvesting systems development cooperation.jpg]] | | [[File:Table 4, Limiting factors of rainwater harvesting systems development cooperation.jpg|left|171px|alt=Table 4, Limiting factors of rainwater harvesting systems development cooperation.jpg]] |
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| − | Table 4: Limiting factors to be taken into account when implementing rainwater harvesting systems through development projects. <ref name="FAO">FAO/Critchley, W., Siegert, K. & Chapman, C. (1991): Water Harvesting. http://www.fao.org/docrep/U3160E/u3160e00.htm#Contents [Access 2012-10-08]</ref><ref name="GIZ (2011a)">GIZ (2011a): Bringing the UNCCD down to earth. Bonn. http://www.desertifikation.de/fileadmin/user_upload/downloads/2011/giz2011-en-Lessons-learned-Bringing-the-UNCCD-down-to-earth.pdf [Access 2012-10-08].</ref><ref name="Prinz">Prinz, D., (1996). Water Harvesting: Past and Future. In: Pereira, L. S. (ed.), Sustainability of Irrigated Agriculture. Proceedings, NATO Advanced Research Workshop, Vimeiro, 21- 26.03.1994, Balkema, Rotterdam.</ref><ref name="UNEP">UNEP (2009): Rainwater harvesting: a lifeline for human well-being http://www.unep.org/publications/search/pub_details_s.asp?ID=4024 [Access 2012-11-18]</ref><ref name="GIZ12a">GIZ (2012a): Good Practices in Soil and Water Conservation, Eschborn. http://www.giz.de/Themen/en/SID-F89EB9ED-AC839C2B/36546.htm [Access 2012-10-08]</ref> | + | Table 4: Limiting factors to be taken into account when implementing rainwater harvesting systems through development projects. <ref name="FAO">FAO/Critchley, W., Siegert, K. & Chapman, C. (1991): Water Harvesting. http://www.fao.org/docrep/U3160E/u3160e00.htm#Contents [Access 2012-10-08]</ref><ref name="GIZ (2011a)">GIZ (2011a): Bringing the UNCCD down to earth. Bonn. http://www.desertifikation.de/fileadmin/user_upload/downloads/2011/giz2011-en-Lessons-learned-Bringing-the-UNCCD-down-to-earth.pdf [Access 2012-10-08].</ref><ref name="Prinz">Prinz, D., (1996). Water Harvesting: Past and Future. In: Pereira, L. S. (ed.), Sustainability of Irrigated Agriculture. Proceedings, NATO Advanced Research Workshop, Vimeiro, 21- 26.03.1994, Balkema, Rotterdam.</ref><ref name="UNEP">UNEP (2009): Rainwater harvesting: a lifeline for human well-being http://www.unep.org/publications/search/pub_details_s.asp?ID=4024 [Access 2012-11-18]</ref><ref name="GIZ12a">GIZ (2012a): Good Practices in Soil and Water Conservation, Eschborn. http://www.giz.de/Themen/de/dokumente/giz2012-en-soil-water-conservation.pdf</ref> |
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| | An enabling environment and governmental support are essential for spreading the concept and implementation of rainwater harvesting systems on a large scale. Mainstreaming in policy agendas, awareness raising, capacity building and technical exchange are all important for enhancing the use of rainwater harvesting systems.<br/>For sustainable impacts of rainwater harvesting systems, experiences of German development projects reveal that a good community organization and moblisation of labour input are essential for the implementation and maintenance of the systems (see Table 1 and 2). The GIZ regional program for implanting UNCCD strategies in Central America and the Carribean benefited from a positive involvement of civil society networks in the implementation and promotion of rainwater harvesting techniques.<ref name="GIZ (2011a)">GIZ (2011a): Bringing the UNCCD down to earth. Bonn. http://www.desertifikation.de/fileadmin/user_upload/downloads/2011/giz2011-en-Lessons-learned-Bringing-the-UNCCD-down-to-earth.pdf [Access 2012-10-08].</ref> | | An enabling environment and governmental support are essential for spreading the concept and implementation of rainwater harvesting systems on a large scale. Mainstreaming in policy agendas, awareness raising, capacity building and technical exchange are all important for enhancing the use of rainwater harvesting systems.<br/>For sustainable impacts of rainwater harvesting systems, experiences of German development projects reveal that a good community organization and moblisation of labour input are essential for the implementation and maintenance of the systems (see Table 1 and 2). The GIZ regional program for implanting UNCCD strategies in Central America and the Carribean benefited from a positive involvement of civil society networks in the implementation and promotion of rainwater harvesting techniques.<ref name="GIZ (2011a)">GIZ (2011a): Bringing the UNCCD down to earth. Bonn. http://www.desertifikation.de/fileadmin/user_upload/downloads/2011/giz2011-en-Lessons-learned-Bringing-the-UNCCD-down-to-earth.pdf [Access 2012-10-08].</ref> |
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| | It is essential to identify and assess potential obstacles before implementing a system. The most appropriate solution, adapted to local circumstances, has to be identified in each situation. This should include assessment of the watershed and its ecological conditions: i.e. rainfall, evaporation, topography, soil properties, soil degradation, and vegetation cover. Remote Sensing and Geographical Information Systems can be used for locating suitable areas. Furthermore, land use and land ownership have to be taken into account, as well as suitable technology and storage medium. To be successful, sustainable and replicable, measures must be technically and physically feasible, of low cost, and have economic benefit for farmers. Especially as some systems are high-maintenance, it is important that rainwater harvesting options are made attractive for farmers themselves to invest in these technologies. | | It is essential to identify and assess potential obstacles before implementing a system. The most appropriate solution, adapted to local circumstances, has to be identified in each situation. This should include assessment of the watershed and its ecological conditions: i.e. rainfall, evaporation, topography, soil properties, soil degradation, and vegetation cover. Remote Sensing and Geographical Information Systems can be used for locating suitable areas. Furthermore, land use and land ownership have to be taken into account, as well as suitable technology and storage medium. To be successful, sustainable and replicable, measures must be technically and physically feasible, of low cost, and have economic benefit for farmers. Especially as some systems are high-maintenance, it is important that rainwater harvesting options are made attractive for farmers themselves to invest in these technologies. |
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| | = Examples of rainwater harvesting measures = | | = Examples of rainwater harvesting measures = |
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| | [[File:Atajado in Potosie with catchment area 2010.jpg|center|259px|Atajados in Potosí District collecting water from an upstream catchment area (Photo: Edmundo Navia).|alt=Atajados in Potosí District collecting water from an upstream catchment area (Photo: Edmundo Navia).]] | | [[File:Atajado in Potosie with catchment area 2010.jpg|center|259px|Atajados in Potosí District collecting water from an upstream catchment area (Photo: Edmundo Navia).|alt=Atajados in Potosí District collecting water from an upstream catchment area (Photo: Edmundo Navia).]] |
| − | <p style="text-align: center;">Figure 5: Atajados in Potosí District collecting water from an upstream catchment area (Photo: Edmundo Navia).</p> | + | <p style="text-align: center">Figure 5: Atajados in Potosí District collecting water from an upstream catchment area (Photo: Edmundo Navia).</p> |
| | <br/>Video in Spanish on atajados in Bolivia: | | <br/>Video in Spanish on atajados in Bolivia: |
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| | <u>For further information on Atajados see:</u> | | <u>For further information on Atajados see:</u> |
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| | *[http://proagro-bolivia.org/ http://proagro-bolivia.org/] | | *[http://proagro-bolivia.org/ http://proagro-bolivia.org/] |
| | *GIZ/Goetter, J. (2010a): Adaptación al Cambio Climático: Cosecha de Agua de Lluvia con “Atajados” en Bolivia, Lima, Peru. [http://www.riesgoycambioclimatico.org/documentos/ACC_con_CA.pdf http://www.riesgoycambioclimatico.org/documentos/ACC_con_CA.pdf] [Access 2012-10-08] | | *GIZ/Goetter, J. (2010a): Adaptación al Cambio Climático: Cosecha de Agua de Lluvia con “Atajados” en Bolivia, Lima, Peru. [http://www.riesgoycambioclimatico.org/documentos/ACC_con_CA.pdf http://www.riesgoycambioclimatico.org/documentos/ACC_con_CA.pdf] [Access 2012-10-08] |
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| | In the southern part of Zambia, the climate is semi-arid / sub-humid with an average rainfall of 700 mm/a. The medium fertile soils are cultivated mainly by poor small-scale farmers with an average land size per household of 2 ha. In order to collect runoff from upstream areas, small earthen dams are constructed (Figure 6). The wall of the dam is compacted for stabilization, the embankment is planted with Kikuyu grass (Pennisetum clandestinum) to prevent erosion, and a fence is built around the dam to stop livestock from entering. Typically, the dam is 50-100 m (length) by 4-8 m (depth) in size, holds a capacity of 50,000 to 100,000 m³, and has a spillway for excess water. The collected water is used for livestock, domestic consumption and irrigation.<br/>The local community is involved in the planning and construction process, and is supported technically and financially by a government agency for the planning, construction and management of the dam. The maintenance of the dam, e.g. (re-)planting of grass on the dam, is conducted by the community, as well as soil and water conservation management of the catchment area. High labour input and well trained technical advisors are required for the construction of the dam, followed by low to medium maintenance requirements.<br/>[[File:Small earth dams Zambia 2011.jpg|center|269px|Construction of a small earth dam in Zambia with communal action|alt=Construction of a small earth dam in Zambia with communal action]] | | In the southern part of Zambia, the climate is semi-arid / sub-humid with an average rainfall of 700 mm/a. The medium fertile soils are cultivated mainly by poor small-scale farmers with an average land size per household of 2 ha. In order to collect runoff from upstream areas, small earthen dams are constructed (Figure 6). The wall of the dam is compacted for stabilization, the embankment is planted with Kikuyu grass (Pennisetum clandestinum) to prevent erosion, and a fence is built around the dam to stop livestock from entering. Typically, the dam is 50-100 m (length) by 4-8 m (depth) in size, holds a capacity of 50,000 to 100,000 m³, and has a spillway for excess water. The collected water is used for livestock, domestic consumption and irrigation.<br/>The local community is involved in the planning and construction process, and is supported technically and financially by a government agency for the planning, construction and management of the dam. The maintenance of the dam, e.g. (re-)planting of grass on the dam, is conducted by the community, as well as soil and water conservation management of the catchment area. High labour input and well trained technical advisors are required for the construction of the dam, followed by low to medium maintenance requirements.<br/>[[File:Small earth dams Zambia 2011.jpg|center|269px|Construction of a small earth dam in Zambia with communal action|alt=Construction of a small earth dam in Zambia with communal action]] |
| − | <p style="text-align: center;">Figure 6: Construction of a small earth dam in Zambia with communal action.<ref name="FAO11">FAO/Liniger, H., Studer, R. M., Hauert, C. & Gurtner, M. (2011): Sustainable Land Management in practice. Prepared by WOCAT. A TerrAfrica Partnership Publication. http://www.fao.org/docrep/014/i1861e/i1861e00.htm [Access 2012-11-10]</ref></p> | + | <p style="text-align: center">Figure 6: Construction of a small earth dam in Zambia with communal action.<ref name="FAO11">FAO/Liniger, H., Studer, R. M., Hauert, C. & Gurtner, M. (2011): Sustainable Land Management in practice. Prepared by WOCAT. A TerrAfrica Partnership Publication. http://www.fao.org/docrep/014/i1861e/i1861e00.htm [Access 2012-11-10]</ref></p> |
| | Due to these dams and the increased water availability, the small-scale farmers obtain an increased crop yield and animal production, resulting in improved income and food security. In addition, the shallow aquifer can be recharged, and the impact of extreme flooding events can be reduced. The communities are strengthened in their institutional capacities through communal action in planning, construction and maintenance.<ref name="FAO11">FAO/Liniger, H., Studer, R. M., Hauert, C. & Gurtner, M. (2011): Sustainable Land Management in practice. Prepared by WOCAT. A TerrAfrica Partnership Publication. http://www.fao.org/docrep/014/i1861e/i1861e00.htm [Access 2012-11-10]</ref> | | Due to these dams and the increased water availability, the small-scale farmers obtain an increased crop yield and animal production, resulting in improved income and food security. In addition, the shallow aquifer can be recharged, and the impact of extreme flooding events can be reduced. The communities are strengthened in their institutional capacities through communal action in planning, construction and maintenance.<ref name="FAO11">FAO/Liniger, H., Studer, R. M., Hauert, C. & Gurtner, M. (2011): Sustainable Land Management in practice. Prepared by WOCAT. A TerrAfrica Partnership Publication. http://www.fao.org/docrep/014/i1861e/i1861e00.htm [Access 2012-11-10]</ref> |
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| | <br/>For further information see: FAO/Liniger, H., Studer, R. M., Hauert, C. & Gurtner, M. (2011): Sustainable Land Management in practice. Prepared by WOCAT. A TerrAfrica Partnership Publication. [http://www.fao.org/docrep/014/i1861e/i1861e00.htm http://www.fao.org/docrep/014/i1861e/i1861e00.htm] [Access 2012-11-10] | | <br/>For further information see: FAO/Liniger, H., Studer, R. M., Hauert, C. & Gurtner, M. (2011): Sustainable Land Management in practice. Prepared by WOCAT. A TerrAfrica Partnership Publication. [http://www.fao.org/docrep/014/i1861e/i1861e00.htm http://www.fao.org/docrep/014/i1861e/i1861e00.htm] [Access 2012-11-10] |
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| | + | == Libón Verde - Rainwater harvesting in Lamielle, Haiti == |
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| | + | The following video describes the success of GIZ supported measures to counteract erosion and the loss of fertile soil along the Libón river in Haiti. |
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| | + | {{#widget:YouTube|id=s2YemC-IJl4|height=500|width=750}} |
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| | + | <br/> |
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| | = References = | | = References = |
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| | <references /> | | <references /> |
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| | + | <br/> |
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| | = Additional Information = | | = Additional Information = |
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| | Agarwal, A. & Narain, S. (2005): Dying wisdom: Rise, fall and potential of India’s traditional water harvesting systems 4th edition. Eds., State of Indias Environment, a citizens’ report 4, Centre for Science and Environment. New Delhi. | | Agarwal, A. & Narain, S. (2005): Dying wisdom: Rise, fall and potential of India’s traditional water harvesting systems 4th edition. Eds., State of Indias Environment, a citizens’ report 4, Centre for Science and Environment. New Delhi. |
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| − | [[Financing_Small-Scale_Irrigation_in_Sub-Saharan_Africa|GIZ/Grimm, J., Richter, M. (2006): Financing small-scale irrigation in Sub-Saharan Africa. Part 2. Case Study Kenya.]] | + | [[Financing Small-Scale Irrigation in Sub-Saharan Africa|GIZ/Grimm, J., Richter, M. (2006): Financing small-scale irrigation in Sub-Saharan Africa. Part 2. Case Study Kenya.]] |
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| | Hasse, R. (1989): Rainwater reservoirs above ground structure for roof catchment. Deutsches Zentrum für Entwicklungstechnologien-GATE. In: Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH. [http://www.itacanet.org/doc-archive-eng/water/Rainwater_reservoirs_GTZ.pdf http://www.itacanet.org/doc-archive-eng/water/Rainwater_reservoirs_GTZ.pdf] [Access 2012-11-18]. | | Hasse, R. (1989): Rainwater reservoirs above ground structure for roof catchment. Deutsches Zentrum für Entwicklungstechnologien-GATE. In: Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH. [http://www.itacanet.org/doc-archive-eng/water/Rainwater_reservoirs_GTZ.pdf http://www.itacanet.org/doc-archive-eng/water/Rainwater_reservoirs_GTZ.pdf] [Access 2012-11-18]. |
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| | Malesu, M, Oduor, A.R., Odhiambo, O.J. eds. (2008): Green water management handbook: rainwater harvesting for agricultural production and ecological sustainability Nairobi, Kenya. World Agroforestry Centre ICRAF. | | Malesu, M, Oduor, A.R., Odhiambo, O.J. eds. (2008): Green water management handbook: rainwater harvesting for agricultural production and ecological sustainability Nairobi, Kenya. World Agroforestry Centre ICRAF. |
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| | + | [http://agriwaterpedia.info/wiki/Water_Harvesting:_Guidelines_to_Good_Practice Mekdaschi Studer, R. and Liniger, H. 2013. Water Harvesting: Guidelines to Good Practice. Centre for Development and Environment (CDE), Bern; Rainwater Harvesting Implementation Network (RAIN), Amsterdam; MetaMeta, Wageningen; The International Fund for Agricultural Development (IFAD), Rome.] |
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| | + | [[Guideline on Irrigation Agronomy|Natural Resources Management Directorate/Natural Resource Sector/Ministry of Agriculture Ethiopia/GIZ (2011): Guideline on irrigation acronomy. Addis Ababa, Ethiopia.]] |
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| | + | [[Small-Scale Irrigation Analysis and Capacity Needs Assessment|Natural Resources Management Directorate/GIZ/Ministry of Agriculture Ethiopia (2011): Small-scale irrigation situation analysis and capacity needs assessment. Addis Ababa, Ethiopia.]] |
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| | PASP (2003): Référentiel des mesures techniques de récupération, de protection et d’exploitation durable des terres. Niamey. | | PASP (2003): Référentiel des mesures techniques de récupération, de protection et d’exploitation durable des terres. Niamey. |
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| | ZEF/Nasr, M. (1999): Assessing Desertification and Water Harvesting in the Middle East and North Africa: Policy Implications: ZEF Discussion Papers on Development Policy Number. Bonn [http://www.zef.de/fileadmin/webfiles/downloads/zef_dp/zef_dp10-99.pdf http://www.zef.de/fileadmin/webfiles/downloads/zef_dp/zef_dp10-99.pdf] [Access 2012-10-08] | | ZEF/Nasr, M. (1999): Assessing Desertification and Water Harvesting in the Middle East and North Africa: Policy Implications: ZEF Discussion Papers on Development Policy Number. Bonn [http://www.zef.de/fileadmin/webfiles/downloads/zef_dp/zef_dp10-99.pdf http://www.zef.de/fileadmin/webfiles/downloads/zef_dp/zef_dp10-99.pdf] [Access 2012-10-08] |
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| | + | [http://www.excellentdevelopment.com/home http://www.excellentdevelopment.com/home] - Pioneering Sand Dams |
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| | + | [[Category:Technologies]] |
| | + | [[Category:Excellent]] |
