Egypt's foreign and irrigation ministers are headed to Khartoum on Monday for talks over Ethiopia's large-scale dam project which Cairo fears will affect its Nile water supply. 

On their three-day visit, FM Sameh Shoukry and Irrigation Minister Hossam Moghazi are expected to meet with Sudanese and Ethiopian officials who have been engaged in tripartite talks over the past year tackling the issue. 

Last week, Egypt announced that the three countries had received offers from four firms to conduct technical studies on the $4.2 billion dam project. Alaa Yassin, Egyptian spokesperson on the dam issue, had told Al-Ahram that the tripartite committee would meet soon in Sudan to choose a firm.   

The selected firm's report is expected to include the dam's impact on upstream Nile countries Egypt and Sudan, as well as its environmental, social and economic effects. The tripartite committee should have selected a firm by mid-December, according to original agenda. 

Egypt fears Ethiopia's Grand Renaissance Dam, of which 40 percent is built, will adversely affect its share of the Nile water. Ethiopia is building the dam on the Blue Nile, the river's most significant tributary, supplying most of its water.

Egypt has pointed out previously some technical concerns over the dam, including its storage capacity, currently set at 74 billion cubic metres.

Egypt will likely need an additional 21 billion cubic metres of water per year by 2050, on top of its current 55 billion cubic metre quota, to meet the water needs of a projected population of 150 million, according to Egypt's National Planning Institute.

The 6,000 megawatt dam, set to be Africa's largest, is expected to be fully completed by 2017.