In water stressed regions such as the Central Rift Valley of Ethiopia, increasing Crop Water Productivity (CWP) is imperative for sustainable food and water security. This PhD research presents CWP of Teff (Eragrostic Tef), a staple food in Ethiopia and an important export crop. Field experiments were conducted under irrigated agriculture during the dry seasons in the periods: 1) November 2010 to March 2011; and 2) December 2011 to April, 2012 at Melkassa Research Centre in Ethiopia. Teff crop was irrigated at four different water application depths ranging from 100% to 25% of the optimum Crop Water Evapotranspiration (ETc) during the four growing stages, the initial, development, mid season and late season. The effect of seeding rates at 25 kg/ha and 10 kg/ha on lodging and yield of the crop was also determined. Overall, the research has demonstrated the potential and the limitations of combining experimental fieldwork with modelling to optimize agricultural water productivity for Teff cultivation.