1. Introduction

The Nile Basin is one of the largest basins in the world shared by eleven countries. The principal tributaries of the Nile River are the White Nile, flowing from the Great Lakes region of Central Africa and the Blue Nile (Abay), Sobat (Baro-Akobo) and the Atbara (Tekeze), flowing from the highlands of Ethiopia. Ethiopia contributes close to 85% of the Nile river flow. The Nile basin is entering into a new era of challenges and opportunities primarily driven by population explosion, food and water shortage, increase in water demand and water use, climate change, and complicated water right issues. More importantly, upstream countries started to assert their right to develop the Nile water resources challenging the long-held water right hegemony of Egypt and Sudan. Ethiopia unilaterally launched the construction of Grand Ethiopian Renaissance Dam (GERD). The sheer size and storage capacity of GERD has initiated dialogue and diplomacy towards understanding of the current reality in the basin as well as the absolute need of co-operative water resource development. This chapter provides an overview to the Nile basin along with the social, economic, environmental and political implication of GERD. The book mainly focuses on the Blue Nile basin, the GERD design, filling and operation in association with the larger Nile basin.