The downstream part in the Imbo Plain has V-shaped valley with low slopes, and is most exposed to the risk of flooding.

[6] In April 2018 the Mutimbuzi River in the Buterere area, which had been diverted from its bed, had destroyed over 300 houses, flooded others and devastated many fields.

[7] In October 2018 the Burundi Civil Aviation Authority began dredging the Mutimbuzi River to prevent it from flooding into the airport.

However, given lack of funding and the risk of floods, the agency soon allowed the cooperatives that did manual dredging to resume work.

The cooperatives would pay OBUHA for the construction materials they retrieved, and were committed to building dikes and planting trees to protect the river banks.