Millet production in the Sourou Valley is aided by irrigation. - - Development of the Sourou Valley. The government of Burkina Faso has declared the development of the Sourou Valley top priority. In 1984, construction began on a dam on the Black Volta River and on an irrigation canal leading from it to the Sourou Valley. Volunteer workers receive free transportation to the work sites by the army. The project is expected to provide irrigation for 30 000 hectares. Rice, wheat, sorghum, corn and truck gardens will be the food crops and wheat, sugarcane and soya, the cash crops. Costs of the dam construction and the irrigation canal will be borne by the Government of Burkina Faso, but the development of the resulting 30 000 hectares must be financed by external sources, such as FAO.