The Gilgel Gibe III Dam is a 250 m high roller-compacted concrete dam with an associated hydroelectric power plant on the Omo River in Ethiopia. It is located about 62 km (39 mi) west of Sodo in the Southern Nations, Nationalities, and Peoples' Region. 

Roller-compacted concrete (RCC) or rolled concrete (rollcrete) is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Portland cement.

The partial substitution of fly ash for Portland Cement is an important aspect of RCC dam construction because the heat generated by fly ash hydration is significantly less than the heat generated by Portland Cement hydration. This in turn reduces the thermal loads on the dam and reduces the potential for thermal cracking to occur.

RCC is a mix of cement/fly ash, water, sand, aggregate and common additives, but contains much less water. 

It has been the third largest hydroelectric plant in Africa with a power output of about 1870 Megawatt (MW), thus more than doubling total installed capacity in Ethiopia from its 2007 level of 814 MW. It was opened in 2015.

The Gibe III dam is part of the Gibe cascade, a series of dams including the existing Gibe I dam (184 MW) and Gibe II power station (420 MW) as well as the planned Gibe IV (1472 MW) and Gibe V (560 MW) dams. The existing dams are owned and operated by the state-owned Ethiopian Electric Power, which is also the client for the Gibe III Dam.

According to en.wikipedia