As water flows down any river there has to be agreement with users both downstream and upstream. If downstream users block the waters then upstream will have backlash of sever flooding. On the other hand if upstream users block the water then downstream users will suffer shortages and in severe case drought and famine may occur.
Mishandling of natural resources could cause wars.
In this video Frank Nuramuzi Executive Director Of NAPE in Uganda discusses the struggles over the Nile due to conflict and the demands for resources. With the discovery and extraction of oil and gas in the western parts of Uganda he fears that political conflicts might be triggered if they are not handled well and the countries may end up in wars. Together with the building of dams as mentioned here in this post previously he stresses that it is extremely important for discussion by all parties and leaders and the communities need to be kept informed and work together.