In pre-Columbian Aztec society, calpulli (from Classical Nahuatl calpōlli, Nahuatl pronunciation: [kaɬˈpoːlːi], meaning "large houses", singular calpul[1]) were units of commoner housing that had been split into kin-based or other land holding groups within Nahua city-states or altepetls.
[2] The inhabitants of a calpul were collectively responsible for different organizational and religious tasks in relation to the larger altepetl.
[4] The primary functions of the calpulli were to coordinate land use for growing crops, food production, and manufacturing tribute.
Tribute was owed by each tributary unity, typically determined as a group of course[clarification needed] and co-residents.
[7] Chinampas' effective built-in drainage systems allowed for the flow of water and sediment, which was then stored as mud and used for fertilizer.