Rethinking water storage for agricultural adaptation to climate change in sub Saharan Africa. Dr. Matthew McCartney and Dr. Irit Eguavoen Tropentag Conference on International Research on Food Security, Natural Resource Management and Rural Development Tropentag ,Zürich, 16 September 2010

1. Rethinking water storage for agricultural adaptation to climate change in Sub-Saharan Africa Dr. Matthew McCartney¹ and Dr. IritEguavoen² Tropentag Conference on International Research on Food Security, Natural Resource Management and Rural Development Tropentag,Zürich, 16 September 2010 Research funded by: 1= International Water Management Institute, 2= ZEF, Center for Development Research, University of Bonn

3. Project rationale – water storage as adaptation to CC*

4. Water Storage Continuum

5. Approach

6. Research results – example Koga watershed

7. Project output – evaluation metrics*CC- Climate Change

8. Project 2008-2011 Objective Guidance on storage options that ensure optimal adaptation to CC-induced impacts on water availability in SSA* Research Questions How can the need for water storage and the effectiveness and suitability of different storage options be evaluated and compared for different climate scenarios? How can water resource planning and management processes be modified to better account for the uncertainties arising from climate change? Principal output Guidelines on how to build climate change into decision-making processes for the planning and management of agricultural water storage in sub-Saharan Africa *SSA- Sub-Saharan Africa

9. Project 2008-2011 Blue Nile River basin/ Ethiopia Volta River basin/ Ghana Source: IWMI Partners Arba Minch University (AMU), Ethiopia Ethiopian Economic Association (EEA) Water Research Institute (WRI), Ghana Institute of Statistical, Social and Economic Research (ISSER), Ghana Center for Development Research (ZEF), Germany Potsdam Institute for Climate Impact Research (PIK), Germany Source: ZEF- Centre for Development Research, GLOWA Volta project

10. Project Rationale Water storage is widely advocated as a key mechanism for CC adaptation Little analysis of how CC affects existing water storage or how to account for CC in the planning and management of new water storage Photo credit: Irit Eguavoen, ZEF

11. Physical Water Storage Continuum Conceptual overview developed by project participants (IWMI Policy Brief 31)

12. Project Rationale Each type has niche in terms of technical feasibility, socioeconomic suitability, externalities and institutional requirements Considered within the context of a basin or a sub-basin, they can collectively contribute to overall water and food security CC will affect the function and operation of different storage types, differently Because of uncertainties in CC predictions, storage options need to be able to function under a range of CC scenarios How to build consideration of CC into the planning and management of water storage?

14. The effectiveness of different options

16. CC scenarios (downscaled to the basins)

17. Current and future storage plus water use in each basin

18. Evaluation of climate change impacts on storage at the basin scale

20. future water resource development Results: Water availability for irrigation/hydropower Effectiveness of existing and planned storage SWAT: Soil and Water Assessment Tool SWIM: Soil and Water Integrated Model WEAP: Water Evaluation and Planning

21. Climate Modeling (Blue Nile and Volta) Approaches of downscaling Dynamical climate models: CCLM and REMO (both for A1B) + bias correction Statistical climate model: WettReg (for different scenarios and GCMs) Resolution: 0.5° (attempt 10 km but not yet complete) Further regionalization / interpolation to locations of interest Mean annual total precipitation (mm) 1971-2000 Source: Hattermann 2010 CCLM: Climate Limited AreaModellingREMO:Regional Model

22. Hydrological Modeling (sub-catchments) Rainfall-Runoff simulation to determine impacts of CC on flow regimes and groundwater recharge Daily simulation to deduce impacts on extremes – floods and droughts

24. Water accounting model (mass balance) – optimizes water use (monthly time-step) Sources of data MoWR: Ministryof Water Resources

26. rules & regulations

27. land & water rights

28. management bodies

29. resettlement & compensation

30. livelihood change

32. identification of water sources

33. cost & benefits of water storage

34. farmers´ perception of storage and climate change (data analysis on-going) Indris Source: ZEF

35. Research results – Blue Nile basin Blue Nile/ Ethiopia Existing and planned schemes Results (no climate change) Source: McCartney et al. 2009

36. Regulated flows Unregulated flows (downstream of proposed dams and unregulated rivers) Beles hydropower transfer Gilgel Abay Ribb Gumara Megech 1925 216 244 176 Koga Intermediate flow Gondar town 2180 116 246 Lake pumping schemes Lake Tana Andassa 270 Tis Issat Falls Tis Abay power plants Legend Abay (Blue Nile) Irrigation Scheme Mean annual inflow (Mm3) 116 Dam Withdrawals Return flow Rivers Water Resource Modeling WEAP model set up for Lake Tana sub-basin Source: McCartney et al. 2010

37. Koga site Source: Image provided by ZEF, obtained from the Koga irrigation project planning office

38. Research results – Koga watershed Evaluating the technical Performance of the Koga and Gomit reservoirs in the Blue Nile under Existing Conditions and Possible Climate change Fuad Abdo Yassin & Matthew McCartney RRV for Koga and Gomit dams in the Nile Basin: Challenge = need to be able to compute these metrics for a number of storage types within a storage system

39. Research results – Koga watershed Tropentag 2010 poster session: water management Evaluating the technical Performance of the Koga and Gomit reservoirs in the Blue Nile under Existing Conditions and Possible Climate change FuadAbdoYassin & Matthew McCartney Poster created by FuadAbdoYassin & Matthew McCartney

40. Research results – Koga dam & irrigation Institutional and organizational aspects of irrigation management Pilot project for farmer-based management - runs at risk to fail Re-organization of farmers in groups – unclear formal/ legal status Training and involvement of farmers – not sufficient Livelihood changes through irrigation agriculture – unexpected workload Conflicts with Christian orthodox authorities – holidays and religious duties How Winners become losers. Relocatees re-establishment of livelihood. Delay in land allocation - long period of non-farming 400 households were relocated to close town Irregularities in compensation payments Change of livelihood - giving up livestock rearing/ urban activities Process of urbanisation, integration in small town settlement Problems with land for houses Importance of social networks New sources of vulnerability (e.g. HIV/ AIDS) Source: Tesfai 2010, Marx 2010

42. The effectiveness of different options

44. The same for all storage types

45. Applicable across a range of scales

46. Applicable now and under climate change scenarios

47. Transparent in its evaluation approach

48. Easy to use by advisers and policy makers

49. Illustrate policy options

50. Include veto/ exit options, if needed► score-based approach, possible to visualize

52. The effectiveness of different options technical economic environ- mental Social evaluation criteria Accessibility 2a. Social cost 2b. Social benefits Management/ Maintenance 4. Options to Adapt social Water storage needed? YES. Water storage effective? YES. socio- economic 2a. Social cost - Measures the social cost of the storage system. Topics: relocation/ compensation, social stratification, social and patronage networks, bargaining power, conflict, health The lower the social cost the greater the social value of the storage system.

53. Social cost scores (emic perspective) Does the project entail high social costs? ► No (score 4-3). ► Considerably high (score 2) ► Continue ► Yes (score 1 - veto) ► Stop because not suitable.

54. Thank you. Project leadership: Dr. Matthew McCartney IWMI East African regional office Addis Ababa m.mccartney@cgiar.org IWMI project homepage: http://africastorage-cc.iwmi.org/Default.aspx ZEF project homepage: http://www.zef.de/1393.html

55. References Eguavoen, I. (2009) The aquisition of water storage facilities in the Abay River basin, Ethiopia. ZEF Working Paper 38. Hattermann, Fred (March 2010). Regional climate scenarios for the Blue Nile and Volta. PIK presentation. IWMI (2009) Flexible Water Storage Options and Adaptation to Climate Change. Policy Brief 31 Johnston, R.& McCartney M. (2010) Inventory of Water Storage Options in the Blue Nile and Volta River basins. IWMI Working Paper 140. Marx, S. (2010) Chances and Obstacles in Implementing a large-scale Irrigation Schememanaged by Farmers: Koga Irrigation and Watershed Management Project. Field research report. Bonn. ZEF. McCartney, M.P., Ibrahim, Y., Seleshi, Y. & Awulachew, S.B. (2009) Application of the Water Evaluation and Planning Model (WEAP) to simulate current and future water demand in the Blue Nile. In: Awulachew, S.B., Erkossa,T., Smakhtin, V. & Fernando, A. (Eds) Improved water and land management in the Ethiopian Highlands: Its impact on downstream stakeholders dependent on the Blue Nile: Intermediate Results Dissemination Workshop 5-6 February, 2009. Addis Ababa, Ethiopia. 78-88. McCartney, M.P., Alemayehu, T., Shiferaw, A. & Awulachew, S. B. (2010) Evaluation of current and future water resources development in the Lake Tana Basin, Ethiopia. Colombo, Sri Lanka: International Water Management Institute. Colombo, Sri Lanka: International Water Management Institute. IWMI Research Report 134. Tesfai, W. (2010) Relocatees re-establishment of livelihood in the Koga irrigations project, Amhara Region, Ethiopia. Field research report. Bonn. ZEF.