The Ndurumu River () is a river in Karuzi Province, Burundi. It is a left tributary of the Ruvubu River.
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. It is one of the main tributaries of the Ruvubu.
The surroundings of the Ndurumu River are a mosaic of farmland and natural vegetation. The area is quite densely populated, with 239 inhabitants per square kilometer as of 2016. The average annual temperature in the area is . The warmest month is September, when the average temperature is , and the coldest is April, with . Average annual rainfall is . The rainiest month is December, with an average of of precipitation, and the driest is July, with of precipitation.
The Buhiga Hydroelectric Power Station is on the Ndurumu River, near the town of Buhiga. The power station has a hydraulic head of and installed power of 220 kW using an Ossberger turbine. A concrete masonry gravity dam diverts water from the upper Ndurumu River into the intake and settling area. From there, it flows through a power canal, then down a steel penstock to the turbogenerator.