The Ndurumu River rises in the north of Karuzi Province and flows south past Buhiga and Karuzi, then south-southwest parallel to the RN 12 highway down to the border with Gitega Province, where it joins the Ruvubu River.

[2] The surroundings of the Ndurumu River are a mosaic of farmland and natural vegetation.

The warmest month is September, when the average temperature is 23 °C (73 °F), and the coldest is April, with 18 °C (64 °F).

[7] A concrete masonry gravity dam diverts water from the upper Ndurumu River into the intake and settling area.

From there, it flows through a 440 metres (1,440 ft) power canal, then down a steel penstock to the turbogenerator.