According to the petitioners, collectively known as the Himba people, generations of their ancestors’ graves would be flooded by the planned construction in the north-east region of Kunene.
Many people would also be forced to move from the area and find new places to live.
The declaration to the government and the UN was signed by 26 tribal chiefs. They are demanding a greater say in decisions affecting them, citing the UN Declaration on the Rights of Indigenous Peoples.
During last year’s consultations with the government, the tribal leaders flatly rejected the ambitious dam project, which would produce 1,700-gigawatts of electricity in the southern African nation.
“We don’t understand why we have to repeat ourselves and the government of Namibia is not listening to us, and is continuing to push for the construction of the dam without our consent,” according to hand-written five-page petition.
The tribes are being aided by local rights group Namrights. Together, they have asked the UN’s special expert on the human rights of indigenous people to visit the vast and sparsely populated nation of 2 million people.