In 2017, Kenya launched a national chapter of the Billion Dollar Alliance for WH to construct one million water ponds (Imbai and Onyango 2017). Such initiatives can help African citizens to secure their water needs during prolonged droughts. In 2005, Egypt officially endorsed a National Water Resources Plan (NWRP) to support economic development based on sustainable resource use and to avoid serious water shortages in the future (Egypt, Ministry of Water Resources and Irrigation 2005). The most effective way of utilizing available water resources in an environmentally safe and economical manner is to store it using low-cost techniques where water is collected from watercourses and distributed for its beneficial use. There are two forms of floodwater harvesting: floodwater harvesting within stream bed and floodwater diversion (Prinz and Singh 2000).


4.4 Water use efficiency


Over the past few decades, there has been a surge in global water consumption. This trend is expected to continue into the future


Figure 5: Water-use effeciency by region (US$ per m3


World Oceania


Melanesia, Micronesia, Polynesia Australia and New Zealand


Northern America and Europe Europe


Northern America


Eastern Asia and South-Eastern Asia South-Eastern Asia


Eastern Asia 3.7 Latin America and the Caribbean


Western Asia and Northern Africa Western Asia


Northern Africa Sub-Saharan Africa


Central Asia and southern Asia Central Asia Southern Asia


1.9 1.5 1.9


5.1 6.7 7.9 10.0 12.9 14.8 20.9 ), 2015 15.2 34.4 38.2 33.2 46.0


50.0 50.3


and water scarcity is seen as a global systemic risk. Agriculture consumes 90 per cent of freshwater, making it the largest consumer of this resource, with irrigation being responsible for approximately 70 per cent of total blue water use (Gleick 2014; Hoekstra et al. 2012). Insufficient water resources can thus greatly undermine agricultural production and the situation can be more dramatic with climate change (Geng et al. 2019).


In agriculture, water-use efficiency (WUE) is a broad concept that can be defined in many ways (Cai et al. 2011; Singh, Wani, Pathak and Singh 2011). From an engineering perspective, improving WUE can be achieved by reducing water losses from drainage, canal seepage, non- productive evaporation, and by using water saving devices (Schaldach et al. 2012). In agricultural production, WUE is often defined as physical and economic outputs per unit of water use, i.e., ‘more crop per drop’ (Fishman et al. 2015). FAO defines irrigation WUE as the ratio between effective water use and actual water withdrawal (2018). By improving application, conveyance, distribution, and management of irrigation;


Source: FAO (2019)


43


Our Water, Our Life Force


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