The Grand Ethiopian Renaissance Dam (GERD) is not just an engineering structure, but a project intertwined in Ethiopia’s constitutionalized ethnic politics. Ethiopia since 1991 is ruled by dominating ethnic entities. Location of projects is influenced by politics. This is not a chapter to review governance in Ethiopia or the 100s of thousands dead and millions displaced in ethnic conflicts. But to show political systems influence on dam engineering and ethnic competition for limited resources. The analysis of GERD site and size selection leaving out the driving forces of the site selection, construction, contracts, operation, and negotiation with downstream riparian countries cannot be complete without this background. The GERD site was selected secretly without input from experts in the country and in the diaspora. The Ethiopian constitution of 1995 divided the country into 9 ethnic “autonomous” regions which can secede if they wish to and take any national infrastructure in their region. Any opportunity to benefit from power through endemic corruption and ethnic rivalry is not missed. The GERD site geographically is at the Border dam site of the 1960s USBR study. But the size is seven times more than the USBR recommendation resulting in a large surface area and high cost. The real reason of the site selection was based on the small ethnic regional state (Kilil), Benishangul-Gumuz, location than the better dam sites upstream that could encroach to the large ethnic groups of the Amhara and Oromo regions. The plan for incorporating Benishangul-Gumuz into Tigray will be easier through population dilution and coercion-based referendum based on the constitution and who is in power at the time. Since 2018, another ethnic group elites have taken over the state power and pursuing the same modus operandi.