Kamal Khan Dam has a 52 million cubic meters capacity and will irrigate 174,000 hectares of land.
President Ghani on Wednesday visited western Nimroz province where he officially inaugurated the Kamal Khan Dam.
First and second vice presidents Amrullah Saleh and Mohammad Sarwar Danish and other government officials were also at the inauguration ceremony.
The dam in Chahar Burjak district of the province has a 52 million cubic meters capacity and will irrigate 174,000 hectares of land.
The dam is located 95 kilometers from the city of Zaranj, capital of the province.
The dam built along the Helmand River will irrigate 174,000 hectares of land in three districts and will also supply water to the provincial center.
It is expected to provide nine megawatts of power, and, in the first stage, it will store 52 million cubic meters of water, according to the National Water Affairs Regulation Authority.
The dam is 16 meters high and is intended to irrigate agricultural lands while also preventing flooding in the province.