Experiences and Lesson Learned from AgWA-FAO program in Africa International Symposium on Rainwater Harvesting and Resilience Addis Ababa, June 1-2 2015 Fethi Lebdi, AgWA Coordinator
The context - Rainfed agriculture in Africa Arable land Rainfed area % of rainfed area (million ha) (million ha) Africa 247 234 94.5 Northern 28 21.5 77.1 Africa Sub-Saharan 218 211 96.7 Africa - 80% of Ugandans depend on rainfed farming which covers 60% of export earnings (CDKN) - In Burkina Faso there are 3.5 millions ha of farming land of which 0.68% is irrigated (INERA); - In Morocco there are 8.4 million ha of farming land of which 1.5 millions ha are irrigated (potential of 1.6) (Aquastat)
Countries overview
Burkina Faso is recurrently hit by droughts that curb agricultural production; Precipitations range between 500 mm/yr in the north and over 1000 mm/yr in the south-west The extreme droughts of the 70s raised the attention on the issue and consequently triggered numerous interventions with strong WH components (e.g. GERES, PAF) (Source: Atlante de l’Afrique , 2005)
Zai pits • Local practice originated in the northern province of Yatenga. It is now also spread all over the central plateau; • Dug during the dry season and enriched with composted manure; • Coupled with stone lines and stone bunds; • Yield can be as high as 1500 kg/ha with good use of FYM; • OM is the limiting factor to higher productivity. (Source: F. Sambalino)
Cordon Pierraux • Used on gentle slopes to slow down runoff, spread it and augment infiltration; • Used in conjunction with Zai pits and demi-lunes; • Can be implemented step-wise over the years as resources become available; • Stones are often the limiting factor. (Source: J. van der Zaag)
Private water harvesting ponds • Government initiative to provide loans and technical assistance to construct over 10.000 ponds (ca. 300 m 3 ); • Used for SSI in small vegetable gardens but designed to water 0.25 ha of Maize; • Promoted all over the country, but started from local initiative near Ouagadougou (Rawalgue). (Source: F. Sambalino)
Water Harvesting Morocco • Precipitations range between 1200 mm/year in the Rif in the North and < 100 mm/year in the south and on the fringes of the Sahara; • In most of the country, crop production is not possible without some forms of irrigation or WH. Source: E. Roose
Water Harvesting Morocco Water Harvesting in Morocco • In the Rif : Metfias, diversion weirs, trenches, and terraces; • In the Semi-arid Areas : , Metfias, terraces, stone and soil bunds, check-dams; • In the South: Metfias , water spreading weir, spate irrigation and Khettara.
Water Harvesting Morocco Metfia – Cisterns • In arid and semi-arid areas • Great variation in size and design; • Communal or private; • Multiple uses , sometimes SSI of small vegetable gardens; • Good government support.
Water Harvesting Morocco Jessours • In arid areas , to harvest water from degraded lateral slopes; • Earthen embankment (Tabia) across dry valleys; • To capture water and build up fertile soil; • Equipped with a lateral spillway;
Water Harvesting Morocco Lac Collinaire and Liman • At the confluence of two (Liman) or three valleys (lac collinaire); • It is being spread on the hills and higher valleys;
Water Harvesting Morocco Spate irrigation • Use of flash floods for production purposes; • Common on the southern side of the Haute Atlas where precipitations are < 200 mm/year; • Can be spread in all arid regions where a wadi and an appropriate topography are present.
Water Harvesting UGANDA • Bimodal rainfall pattern that is more suitable for rainfed production; • Water harvesting for crop production is not well spread except in few locations (e.g. the southwest).
Water Harvesting UGANDA Trash-lines • Improved following a participatory process ( ISWC ) • Crop residues and weeds are heaped in mounds along contour lines; • Preferred to physical structures because they require less work; • Higher yield near the trash-line;
Water Harvesting UGANDA Terraces • Common in the Kabale district (SW) and surrounding hills; • As the population is increasing their use is spreading also in more gentle landscapes – intensification;
Water Harvesting UGANDA Valley dams/tanks • built in Karamoja and in the cattle corridor; • They are used to water cattle even though some first experiences with SSI are present; • Smaller ponds constructed by MoA (with drip - SSI).
Water Harvesting Considerations – The downstream Externalities of (small) WH – Downstream effects - Very few studies available; - There are examples of reduced dam impounding, but also examples of Groundwater Recharge
Water Harvesting Considerations Critchley, 2012: “ an increasing number of studies show that when these small water harvesting interventions become numerous they can have an aggregate impact downstream” Bouma et al., 2011 : “ The results indicate that the downstream impacts are considerable and that net benefits are insufficient to pay back investment costs” Nyssen et al., 2010 : “ Emerging wells and irrigation are other indicators for improved water supply in the managed catchment. Cropped fields in the gullies indicate that farmers are less frightened for the destructive effects of flash floods.” Aboaubdillah, 2009 : “The simulation results have clearly shown that contour ridges (considered as pothole in this study) within the watershed have an important role of the retention of sediments; whereas, they showed to have an impact on the hydrologic regime in the catchment by reducing the surface runoff by 32 % .”
Water Harvesting COMPARATIVE ANALYSIS Burkina Faso Morocco Uganda Mapping of past initiatives Many studies are Scattered and opportunities is being available or in the information, no study Diagnostic studies prepared (INERA-MoA- process (Roose, at national level; WaHaRA) AGIRE factsheets) WH high up in the agenda WH high up in the Only few (PNSR) agenda (Maroc Vert) technologies are Political Agenda prioritized (Valley dams), but present in main policy (NDP) Some regions have been Water harvesting in Lower adoption of changed by a farmer many forms WH measures except movement promoting in situ throughout the valley tanks in the WH; country; cattle belt and in WH on the Karamoja; ground Relevant initiatives in WH and valorisation promoting WH ponds and of production coupled Presence of local SSI to boost benefits; agronomic measures to upscale (trash- lines, mulching)
Water Harvesting COMPARATIVE ANALYSIS Burkina Faso Morocco Uganda Agricultural AES at municipal level, but AES restructured NAADS disbanded, Extension System under funded; (ONCA--CCA) due to (AES) mismanagement and corruption; Inera, 2iE have a strong IAV, INRA, ENAM Research need focus on AWM; cover aspects on strengthening on WH, but could benefit WH; At university level WH can of specific courses; be strengthened; Specific courses on Education and Some technical WH are lacking; Research CAP-Matourkou can be a schools that form key entry to technician technicians have WH formation in their programs; Need of trainings on landscape approach that integrates disciplines Lack of information on downstream externalities Crosscutting Excellent potential to support SSI
Water Harvesting (Some) RECOMMENDATIONS Burkina Faso Morocco Uganda • • • Fertility management Siltation of Lac Valley tanks enhancement Collinair can be coupled with (vermicomposting, rock curbed with SWC; capacity building; • • dust, micro-dosing); WH and WH • Promote cheap carts for Groundwater demonstration plot stone transportation; recharge against should be salinity affordable; Technical • Control ET, leakge and siltation from ponds • Couple road development with WH and SSI • Build up on local initiatives and aim to boost short term benefits • Couple fertility management with WH • Work at landscape level and promoting Recharge, Retention and Reuse (3R) • WH storage developed jointly with skills of users • Farmers innovators and local champions – Farmers Field Schools Capacity • Exchange visits and in-country as well as inter country knowledge exchange building • Capacity building of government staff and • Curricula strengthening knowledge • On the job coaching of technician sharing
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