Ethiopia has begun diverting the Blue Nile as part of a giant dam project, officials said Wednesday, risking potential unease from downstream nations Sudan and Egypt.
The $4.2 billion (3.2 billion euro) Grand Renaissance Dam hydroelectric project had to divert a short section of the river—one of two major tributaries to the main Nile—to allow the main dam wall to be built.
"To build the dam, the natural course must be dry," said Addis Tadele, spokesman for the Ethiopian Electric Power Corporation (EEPCo), a day after a formal ceremony at the construction site.
The natural course of the river was diverted about 550 metres (yards) from its natural course, Addis said, but stressed that water levels would not be affected.
"There is no problem with the river levels," he added.
The first phase of construction is expected to be complete in three years, with a capacity of 700 megawatts.
Once complete, the dam will have a capacity of 6,000 megawatts.
Both Sudan and Egypt, arid nations that rely heavily on the Nile for water including for agriculture, are extremely sensitive about projects that could alter the flow of the river.
However, EEPCo insists the project will not impact downstream needs, claiming the dam will provide "highly regulated outflows" by reducing floods at peak times and providing more water during otherwise low flows.
The dam project, in Ethiopia's northwestern Benishangul-Gumuz region near the border with Sudan, was launched in April 2011 by late prime minister Meles Zenawi.
Funding is being raised publicly, with the state raising funds locally, and no external financing has been provided.
Ethiopia is constructing a series of dams in order to produce hydroelectric power for local consumption and export.
EEPCo has plans to establish transmission lines to neighbouring countries, including Sudan, Kenya and Djibouti.
One of Ethiopia's deputy Prime Ministers, Demeke Mekonnen, officially launched the river diversion Tuesday, alongside EEPCo chief Mihret Dibebe.
When completed the dam wall will stretch almost 1.8 kilometres (about one mile) in length and 145 metres (475 feet) in height.
Explore further: Sudan seeks to tap 'blue gold' with new dam projects