Ethiopia is building its $5 billion Grand Ethiopian Renaissance Dam on the Blue Nile River (the Niles largest tributary). The dam will generate 6,000 megawatts of electricity for domestic use and export
The vast majority of Eygptions live along the Niles bank
There are agreements that give water to Eygpt and Sudan but not the 9 other countries as such they believe they have a historical right to it
Eygpt has threatened Ethiopia but it didn't work so they decided to talk to them. Talks started in 2015 but the Dam was 60% by 2016. They now need to fill resevoir and how quickly they do will affect Eygpt