@onlmaps Funny fact about Czech geography. 🙂 The lake would cover most of Bohemia (historical land), i.e. western part of Czechia. This project has been discussed for almost 30 years and according to https://necyklopedie.org/wiki/%C4%8Cesk%C3%A1_p%C5%99ehrada is then significantly delayed, as all constructions in Czechia... BTW, simulation You paste contains 5 dams, while original project only 2. 😉
Regarding map below, "přehrada" is reservoir (dam), "hráz" is dam and "o." stands for "ostrov" - island.