What is the controversy around the Nile river and How it concerns Ethiopia, Egypt and Sudan?

The UN council recently tried to mediate between the three countries involved in the controversy surrounding the Nile river--Egypt, Ethiopia and Sudan but the stand of all the nations remain unchanged.

But what exactly is this controversy?

So Ethiopia wants to fill a giant dam officially known as the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile, one of the tributaries of the Nile river and upstream nations--Egypt and Sudan believe that this will be a threat to their survival. Egypt, nearly six months ago, had asked for the United States to intervene which was not at all appreciated by Ethiopia.

Together they came to a consensus that Ethiopia will fill the dam only during the wet season but now Ethiopia has decided to go ahead with the process of filling the dam in two weeks. The nation believes that this will be highly beneficial for their people and will boost up their livelihood. Egypt is worried majorly because if Ethiopia plans to fill the dam for a short duration then the flow of the river will be impacted and won’t be enough for Egypt and Sudan. Egypt was the first to raise this concern and further was joined by Sudan. 

Egypt relies on the Nile for 90% of its water. It has historically asserted that having a stable flow of the Nile waters is a matter of survival in a country where water is scarce. A treaty signed in 1929 gave Egypt and Sudan all the control over the Nile river while Ethiopia believes that something that old should not decide the usage of water.

Ethiopia has its reasons to build such a huge dam. Ethiopia has an acute shortage of electricity, with 65% of its population not connected to the grid.The energy generated will be enough to have its citizens connected and sell the surplus power to neighbouring countries.

Each country involved has its own motive so where does that leave us with this controversy? The government officials will now have to come with certain terms that are agreeable to all parties. If Ethiopia does not want foreign mediation, then they can go with regional dialogue and sort the matter. Delaying this matter