It flows along this border in a generally south-southeast direction to the border between Rumonge Province and Bururi Province, which it defines for a short distance, then turns west and flows to its mouth on Lake Tanganyika, which it enters to the south of Magara.

[1] The surroundings of the Ruzibazi River are a mosaic of agricultural land and natural vegetation.

[6] The 15MW Ruzibazi Hydroelectric Power Station is in Rutumo colline, Minago zone in the Commune of Rumonge.

Construction by the Chinese company Sinohydro began in October 2018 and was completed ahead of schedule in July 2022.

It was inaugurated on 6 September 2022 in a ceremony attended by Evariste Ndayishimiye, President of Burundi.