The Ubangi River (; ; ; ), also spelled Oubangui, is a river in Central Africa, and the largest right-bank tributary of the Congo River. It begins at the confluence of the Mbomou (mean annual discharge 1,350 m<sup>3</sup>/s) and Uele Rivers (mean annual discharge 1,550 m<sup>3</sup>/s) and flows west, forming the border between Central African Republic (CAR) and the Democratic Republic of the Congo (DRC). Subsequently, the Ubangi bends to the southwest and passes through Bangui, the capital of the CAR, after which it flows southforming the border between the DRC and the Republic of the Congo. The Ubangi finally joins the Congo River at Liranga.

The Ubangi's length is about . Its total length with the Uele, its longest tributary, is . The Ubangi's drainage basin is about . Its discharge at Bangui ranges from about to , with an average flow of about ~. Its mean annual discharge at the mouth is around ~.

Together with the Congo River, it provides an important transport artery for river boats between Bangui and Brazzaville. From its source to below Bangui, the Ubangi defines the boundary between the Central African Republic and the Democratic Republic of the Congo (DRC). Thereafter, it forms the boundary between the DRC and the Republic of Congo until it empties into the Congo River.

thumb|left|Transaqua scheme (in red)

Lake Chad replenishment project

In the 1960s, a plan was proposed to divert waters from the Ubangi to the Chari River. According to the plan, named Transaqua, the water from the Ubangi would revitalize Lake Chad and provide a livelihood in fishing and enhanced agriculture to tens of millions of central Africans and Sahelians. Inter-basin water transfer schemes were proposed in the 1980s and 1990s by Nigerian engineer J.Umolu and the Italian firm Bonifica.

In 1994, the Lake Chad Basin Commission (LCBC) proposed a similar project, and at a March 2008 summit the heads of state of the LCBC member countries committed to the diversion project. In April 2008, the LCBC advertised a request for proposals for a feasibility study.

References

  • Map showing the Ubangi Subbasin at World Resources Institute
  • International Commission of the Congo-Oubangui-Sangha Bassin