Agree. Also, the bulk of the loss occurred after the USSR collapsed because none of the surviving bourgeois countries around it bothered to care about it, while continuing to make money from farming irrigated by its waters (irrigation also built by the Soviets). The Soviets were tabling massive megaprojects to fix it before the USSR was destroyed.
This complaint is the same kind of bullshit as the Baltic states' whining about Soviet oppression, even though their entire modern economies exist only because the Soviet Union elevated them to sapience.
This shit is also the kind of liberal anti-extractivism that is applied only to Global South countries, where liberals get pissed at any Global South country using its own natural resources to advance productive forces in order to elevate living standards and, one day, reverse any environmental degradation created in the process. Apparently, green liberals just want people in Third World countries to live as cavemen forever so that the environment stays pristine.