Skip to main content

Hydrological Impacts of Flood Storage and Management on Irrigation Water Abstraction in Upper Ewaso Ng’iro River Basin, Kenya


The upper Ewaso Ng’iro basin, which starts from the central highlands of Kenya and stretches northwards transcending different climatic zones, has experienced decreasing river flows for the last two decades. The Naro Moru sub-basin is used to demonstrate the looming water crisis in this water scarce river basin. The objective of the study was to show the extent of dry seasons’ irrigation water abstractions on river flows, and to assess the hydrological impact of flood storage on temporal water distribution and irrigation water management. Decreasing river flows are attributed to over-abstraction mainly for irrigating horticultural crops. The number of abstractors has increased four times over a period of 10 years. The amount of water abstracted has also increased by 64% over the last 5 years. Moreover, the proportion of unauthorized abstractions has been increasing over the years, currently at about 80% and 95% during high and low flows respectively. This has resulted in alarming conflicts among various water users. The situation is aggravated by low irrigation efficiency (25–40%) and inadequate flood storage facilities. The paper analyzes over 40 years’ observed river flow data and 5-year interval water abstraction monitoring records for 15 years. It assesses whether flood storage and management, can reduce dry seasons’ irrigation water abstractions without significantly reducing river flows to affect the sustenance of natural ecosystems downstream. The results demonstrate that flood storage and management can reduce water abstraction and increase river flows during the dry seasons, without significantly reducing high flows to affect the downstream water users. However, socio-economic, hydrological and environmental implications should be considered if a sustainable river basin water resources management strategy is to be developed and implemented. The case study of Naro Moru sub-basin is representative of the situation in the other sub-basins, and hence can be taken as a pilot basin for developing an integrated water resources management strategy that will foster socio-economic development with minimal negative hydrological impacts in the water scarce upper Ewaso Ng’iro river basin.

This is a preview of subscription content, access via your institution.


  1. Aeschbacher J, Liniger HP, Weingartner R (2005) River water shortage in a highland–lowland system: a case study of the impacts of water abstraction in the Mount Kenya region. Mt Res Dev 25(2):155–162

    Article  Google Scholar 

  2. Agarwal A, Narain S (1997) Dying wisdom: the rise, fall and potential of India’s traditional water harvesting systems. Centre for Science and Environment (CSE) and Thomson, Faridada, India

    Google Scholar 

  3. Agarwal A, Narain S, Khurana I (2001) Making water everybody’s business: practice and policy of water harvesting. Centre for Science and Environment (CSE), New Delhi, India

    Google Scholar 

  4. Berger T, Birner R, Mccarthy N, DíAz J, Wittmer H (2007) Capturing the complexity of water uses and water users within a multi-agent framework. Water Resour Manag 21(1):129–148

    Article  Google Scholar 

  5. Croke B, Ticehurst J, Letcher R, Norton J, Newham L, Jakeman A (2007) Integrated assessment of water resources: Australian experiences. Water Resour Manag 21(1):351–373

    Article  Google Scholar 

  6. Decurtins S (1992) Hydro-geographical investigations in the Mount Kenya sub-catchment of the Ewaso Ng’iro River. Geographica Bernensia, African Series, A10. Institute of Geography, University of Berne, Berne, Switzerland

    Google Scholar 

  7. Doorenbos J, Pruitt WO (1977) Crop water requirements. Irrigation and Drainage Paper No. 24. Food and Agriculture Organization (FAO) of the United Nations, Rome, Italy

    Google Scholar 

  8. Falkenmark M (2007) Shift in thinking to address the 21st century hunger gap: moving focus from blue to green water management. Water Resour Manag 21(1):3–18

    Article  Google Scholar 

  9. FAO (2003) Solving water conflicts in the Mount Kenya region. CD-ROM: From the International year of mountains to the international year of freshwater. Centre for Development and Environment (CDE) and the Food and Agriculture Organization (FAO). FAO, Rome, Italy

  10. Gathenya JM (1993) Water balance of sections of the Naro Moru River. Unpublished M.Sc. thesis, Department of Agricultural Engineering, University of Nairobi, Nairobi, Kenya

  11. Gathenya JM, Liniger HP, Gichuki FN (2000) Problems of water resources management for a basin west of Mt. Kenya: challenge to water resource planners. In: Gichuki FN, Mungai DN, Gachene CK, Thomas DB (eds) Land and water management in Kenya: Towards sustainable land use. Department of Agricultural Engineering, University of Nairobi, Nairobi, Kenya, pp 175–180

    Google Scholar 

  12. Gichuki FN (2002) Water scarcity and conflicts: a case study of the Upper Ewaso Ng’iro North Basin. In: Blank HG, Mutero CM, Murray-Rust H (eds) The changing face of irrigation in Kenya: Opportunities for anticipating change in Eastern and Southern Africa. IWMI, Colombo, Sri Lanka, pp 113–134

    Google Scholar 

  13. Gichuki FN, Liniger HP, Macmillan L, Shwilch L, Gikonyo JK (1998) Scarce water: Exploring resource availability, use and improved management. East South Afr Geogr J 8(Special issue)

  14. Gichuki FN, Gichuki PG, Muni RK (1999) Characterization of the flow regime of Ewaso Ng’iro North River. East Afr Agric For J 65(1):70–78

    Google Scholar 

  15. Gikonyo JK (1997) River water abstraction monitoring for the upper Ewaso Ng’iro river basin, Kenya. Proceedings of SPPE workshop, Madagascar, 2–6 June

  16. Government of Kenya (GoK) (1972) The water act, chapter 372, laws of Kenya. Government, Nairobi, Kenya

    Google Scholar 

  17. Government of Kenya (GoK) (2002) The water act, Kenya gazette supplement no. 107 (acts no. 9). Government, Nairobi, Kenya

    Google Scholar 

  18. Hedelin B (2007) Criteria for the assessment of sustainable water management. Environ Manage 39(2):151–163

    Article  Google Scholar 

  19. IWMI (2005) Environmental flows: planning for environmental water allocation. Water Policy Briefing, 15, 6 p. International Water Management Institute (IWMI), Colombo, Sri Lanka, Available at

  20. Kithinji GRM, Liniger HP (1991) Strategy for water conservation in Laikipia district. Proceedings of a water conservation seminar, Nanyuki, 7–11 August. Laikipia-Mt. Kenya papers, D-4. LRP and Universities of Nairobi (Kenya) and Berne (Switzerland)

  21. Leibundgut C (1986) Hydrogeological map of Mount Kenya area (1:50,000 map and exploratory text). Geographica Bernensia, Vol. A3, Berne, Switzerland

  22. Liniger HP (1995) Endangered water: a global overview of degradation, conflicts and strategies for improvement. Development and Environment Report No. 12. Centre for Development and Environment, Lang Druck AG., Bern, Switzerland

  23. Liniger HP, Gikonyo JK, Kiteme BP, Weismann U (2005) Assessing and managing scarce tropical mountain water resources: the case of Mount Kenya and the semi-arid upper Ewaso Ng’iro basin. Mt Res Dev 25(2):163–173

    Article  Google Scholar 

  24. NDMC (2006) What is drought?: understanding and defining drought. USA’s National Drought Mitigation Center (NDMC). Available at

  25. Niederer P (2000) Classification and multi-temporal analysis of land use and land cover in the upper Ewaso Ng’iro basin (Kenya) using satellite and geographical information system (GIS). Unpublished M.Sc. thesis. Centre for Development and Environment (CDE), University of Berne, Berne, Switzerland

  26. Ngigi SN (2003) Rainwater harvesting for improved food security: promising technologies in the Greater Horn of Africa. Greater Horn of Africa Rainwater Partnership. Lino, Nairobi

    Google Scholar 

  27. Ngigi SN, Thome JN, Waweru DW, Blank HG (2000) Low-cost irrigation for poverty reduction: an evaluation of low-head drip irrigation technologies in Kenya. IWMI Annual Report 2000–2001:23–29

    Google Scholar 

  28. Ngigi SN, Savenije HHG, Thome JN, Rockström J, Penning de Vries FWT (2005a) Agro-hydrological evaluation of on-farm rainwater storage systems for supplemental irrigation in Laikipia district, Kenya. Agric Water Manag 73(1):21–41

    Article  Google Scholar 

  29. Ngigi SN, Savenije HHG, Rockström J, Gachene CK (2005b) Hydro-economic evaluation of rainwater harvesting and management technologies: farmers’ investment options and risks in semi-arid Laikipia district of Kenya. Phys Chem Earth 30:772–782

    Google Scholar 

  30. NRM (2003) Water abstractions monitoring campaign for the Naro Moru River, Upper Ewaso Ng’iro North Basin. Final Report. Natural Resources Monitoring, Modelling and Management (NRM), Nanyuki, Kenya

  31. Roth S (1997) Land use classification of the upper Ewaso Ng’iro basin in Kenya by means of Landsat TM satellite data. Institute of Geography, University of Bern, Bern, Switzerland

    Google Scholar 

  32. Smakhtin VU, Revenga C, Doll P (2004) Taking into account environmental water requirements in global-scale water resources assessments. Colombo, Sri Lanka: IWMI. v, 24 p. (Comprehensive Assessment of Water Management in Agriculture Research Report 2) Available at

  33. Tharme RE (2003) A global perspective on environmental flow assessments: Emerging trends in the development and application of environmental flow methodologies for rivers. River Research and Applications 19:392–441

    Article  Google Scholar 

  34. Tharme RE (2005) Environmental flows, ecosystems and livelihoods: the impossible dreams. 2nd Southeast Asia Water Forum, Session Report, 31 August, The World Conservation Union (IUCN)

  35. Thomas MK, Mbui SG, Mikwa GG, Kung’u PW, Kiragu GK, Njeru JN, Gitari B, MacMillian LC, Gikonyo JK (1996) Flood utilization study. A report compiled for the Ministry of land Reclamation, Regional and Water Development (Laikipia District) and Natural Resources Monitoring, Modelling and Management (NRM), Nanyuki, Kenya

  36. UNESCO and WMO (2001) The design and implementation strategy of the Hydrology for the Environment, Life and Policy (HELP) program. Doc. No. H00/1 produced by a HELP Taskforce. Available at

  37. United Nations Educational, Scientific and Cultural Organization (UNESCO) (2005) Hydrology for the Environment, Life and Policy (HELP) program. Available at

  38. WRAP (1987) AP Water resources assessment study in Laikipia district. Water Resources Assessment Program (WRAP). Ministry of Water Development, Nairobi, Kenya

    Google Scholar 

  39. Xia J, Zhang L, Liu C, Yu J (2007) Towards better water security in North China. Water Resour Manag 21(1):233–247

    Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Stephen N. Ngigi.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ngigi, S.N., Savenije, H.H.G. & Gichuki, F.N. Hydrological Impacts of Flood Storage and Management on Irrigation Water Abstraction in Upper Ewaso Ng’iro River Basin, Kenya. Water Resour Manage 22, 1859–1879 (2008).

Download citation


  • River water withdrawals
  • Low river flows
  • Water conflicts
  • Flood storage
  • River basin water resources management