Technology for a Solar-Punk future.
Airships and hydroponic farms...
The whole point of this article is the apparent culture that made these irrigation methods possible. However, instead of telling you about it, it keeps repeating itself, over and over again, and never really tells you why or what made irrigation better 1,500 years ago.
The article is 6 A4 pages long, and can very succinctly be summised in those 4 lines OP attached to the post as a lure.
The article is definitely lacking details about the Moche and Chimu cultures. The coast of Peru has a history of severe droughts and floods and landslides and earthquakes, yet these people had advanced irrigation systems and managed to live in such an environment for centuries. From what I understand, it's the communal management and temporary nature of the irrigation infrastructure that differs from modern methods, but the how of managing it and moving it over time is left out. If anyone knows more, perhaps they can comment here.