01 / The world before
Rainfall variation constrained cultivation.
02 / The discovery
Hydrology and engineering made planned water delivery possible.
03 / The people
Farmers, water managers and agricultural engineers.
04 / The obstacles
Water use and ecological trade-offs cannot be ignored.
05 / The world after
Farming could expand or stabilize in some settings.
06 / Why it still matters
Sustainable irrigation requires local water accounting.