In April 2009
Banro Corporation, a Canadian gold miner, reported results of a feasibility study for a hydroelectric power plant on the river. The project would exploit a drop in the river over a distance of . It would cost about US$133.8 million, giving a "green" source of power for the
Twangiza gold project. The mining concessions cover and are located south-southwest of
Bukavu. The proven and probable reserve based on a 0.5-gram-per-tonne cutoff grade is 4.54 million ounces of gold. The planned power plant will be in a "pristine montane forest", and will impact local fish-farming. A study showed that 1,860 households living in the area between the Twangiza and Lulimbohwe rivers would be affected, with 1,257 having to be resettled. Most of the people are farmers or artisanal miners. In the rivers downstream of the project about 1,725 workers are engaged in recovery of gold, tin, tungsten and tantalum, in operations controlled by various rebel groups and warlords, often under the protection of local authorities. The illegally extracted metals are sold on the black market. Decades of
artisanal mining have contaminated the river beds with lead, chromium, arsenic and possibly mercury. ==References==