The need to improve food production in semi-arid environments of sub-Saharan Africa cannot be overemphasized. Agricultural production is generally low (1 ton haÝsuperscript -1¨), which is synonymous with a poverty threshold of US$1 dayÝsuperscript -1¨. The situation is aggravated by water scarcity where many countries are below the per capita water security threshold of 1,000mÝsuperscript 3¨ yrÝsuperscript -1¨. However, despite the seemly desperate situation, rainwater harvesting and management (RHM) is a viable intervention for upgrading rainfed agriculture, improving water supply and sustainable livelihoods in water-scarce river basins. The overall objective was to assess the hydrological impacts of land use changes on water resources management and socio-economic development of upper Ewaso Ng'iro river basin in Kenya. This was accomplished through field survey of potential RHM systems, comparative case studies, agro-hydrological and hydro-economic evaluation of on-farm storage & in-situ RHM systems and assessment of the impacts flood storage on dry season irrigation water abstractions.