[AStonesThrow]

I am not sure of their operational status today, but in Medieval Western Europe, it was Carmelite communities who built aqueducts; even as they struggled to reform themselves during the Counterreformation, religious communities were undertaking large-scale engineering projects, because they controlled enough labor workforce, as well as technology and supply chains, to make that happen.

I would be unsurprised if the Carmelite Orders likewise invested significant maintenance in the old Roman construction, and learned from it as well.