The Gilgel Gibe II consists of a power station on the Omo River that is fed with water from a headrace tunnel and sluice gate on the Gilgel Gibe River. The headrace tunnel runs 26 km (16 mi) under the Fofa Mountain and at its end, it converts into a penstock with a 500 m (1,600 ft) drop. When the water reaches the power station, it powers four Pelton turbines that
operate four 107 MW generators. Each turbine is 3.5 m (11 ft) in diameter.In 2004, the Government of Ethiopia secured €220 million from the Government of Italy for construction. The total cost of construction is €373 million with €50 million provided by the European Investment Bank, and the remaining €103 million from the Ethiopian Government. Construction on the power plant began on March 19, 2005, with Salini Costruttori as the main contractor. The power station was originally slated to be complete in late 2007 but was delayed because engineering problems encountered during construction. In March 2005, the contract to excavate the tunnel was awarded to SELI and in October 2006, a tunnel boring machine (TBM) hit a fault, delaying the project. On June 9, 2009, both TBMs met each other and the tunnel was ready for hydraulic testing that September. The tunnel is "considered one of the most difficult tunnel projects ever undertaken, due to the critical, and in some reaches, exceptionally adverse, ground conditions." The power station was inaugurated on January 14, 2010.