Book excerpt: This report describes the water accounting study for the Nile River Basin carried out by IHE-Delft using the Water Productivity (WaPOR) data portal of the Food and Agricultural Organization (FAO). The Nile River Basin faces a huge challenge in terms of water security. With an expected doubling of the population in the basin in the next twenty-five years, water supply in the basin will be further depleted as demands for agriculture, domestic and industry continues to grow. Water availability in the basin will also be threatened by climate change and variability and pollution from increased agricultural and industrial activities and from urban areas. However with limited up-to-date ground observations, in terms of duration, completeness, and quality of the hydro-meteorological records it is difficult to draw an appropriate picture of the water resources conditions. The Water Accounting Plus (WA+) system designed by IHE Delft with its partners FAO and IWMI has been applied to gain full insights into the state of the water resources in the basin.