Comment by rad_gruchalski
4 days ago
https://en.m.wikipedia.org/wiki/Acre-foot
> The acre-foot is a non-SI unit of volume equal to about 1,233 m3 commonly used in the United States in reference to large-scale water resources, such as reservoirs, aqueducts, canals, sewer flow capacity, irrigation water,[1] and river flows.
Seems to be.
It's a surprisingly convenient unit of measurement. Rainfall and irrigation typically are 0-1m per year, so if you have a 10acre farm you need 10acre-m of water to grow... Though, can't mix units, that would be silly :).