[LibertarianLiz]

Man-made reservoirs, held behind some 1 million dams

This is the real lefty bugaboo: dams. They hate dams.

[where's_the_Outrage?]

According to this website there are only 515,176 Reservoirs of over 2.5 acres in the world.
https://www.currentresults.com/Environment-Facts/number-reservoirs-in-world.php

I guess some have multiple dams as GW research would never exaggerate.