https://en.wikipedia.org/wiki/Reichskommissariat_MoskowienThe administrative capital was tentatively proposed as Moscow, the historical and political center of the Russian state. As the German armies were approaching the Soviet capital in the Operation Typhoon in the autumn of 1941, Hitler determined that Moscow, like Leningrad and Kiev, would be levelled and its 4 million inhabitants killed, to destroy it as a potential center of Bolshevist resistance. For this purpose Moscow was to be covered by a large artificial lake which would permanently submerge it,[1][2] by opening the sluices of the Moscow-Volga Canal.[3] During the advance on Moscow Otto Skorzeny was tasked with capturing these dam structures.[3]
If the Nazis won the war, would Moscow have been razed and turned into an artificial lake like Hitler wanted and could it plausibly have been accomplished?