How do irrigation canals work?

Irrigation canals are used to move water from a source, whether a stream, reservoir, or holding tank. The canal may be a few feet wide and less than a foot deep, or very wide, and several feet in depth. flow gates, sluice gates, or valves control the flow of water from the source, to the point of use. read more

Irrigation canals don't always deliver the water directly to the soil being irrigated; in many cases, the water must be delivered from the canal to the crops in other ways. One common way of doing this is to divert water from the canal into irrigation ditches, or "laterals," dug in close proximity to crop rows. read more

The earliest agricultural irrigation canal system known in the U.S. dates to between 1200 B.C. and 800 B.C. and was discovered in Marana, Arizona (adjacent to Tucson) in 2009. The irrigation canal system predates the Hohokam culture by two thousand years and belongs to an unidentified culture. read more