Ethiopian television on Tuesday celebrated the start of a project to divert the Blue Nile, one of the Nile River’s two major tributaries, Turkish news agency Anadolu reported.

The Ethiopian government's decision to divert the river surprised many observers when it was announced on Monday.

The power-generating dam will reduce Egypt's and Sudan’s share of Nile River water by 18 billion cubic meters annually, Egyptian Minister of Irrigation and Water Resources Mohamed Bahaaeddin predicted in comments published in the Ethiopian Review.

Ethiopian government spokesperson Bereket Simon said he expects "outrage" from the downstream countries of Egypt and Sudan, which fear their share of the Nile's water will be reduced. 

The project is the first of its kind by an upstream Nile Basin country.

Egypt has been suffering from water shortages over the past few years. According to the National Planning Institute, Egypt will need an additional 21 billion cubic metres of water per year by 2050, on top of its current 55 billion cubic metres quota of Nile water, to meet the needs of a projected population of 150 million people.