It is unknown who first irrigated his crops with water brought specially from a nearby river, but archeological evidence suggests that, wherever farming began to take place, irrigation soon followed. There is evidence of irrigation from around 6000 b.c.e. in Sumer in Mesopotamia, and also on ancient Egyptian farms near the Nile. Some 2,000 years later, irrigation occurred in Geokysur in South Russia, and in the Zana Valley in the Andes Mountains of Peru. By 3000 B.C.E., the the same techniques were used by the Indus Valley Civilization in what is now Pakistan.
When, at around 6000 B.C.E., the first farmers in Mesopotamia planted their crops of barley, wheat, and other plants near the Tigris or Euphrates rivers, they relied on rain, the occasional flood, and the ability of the soil to hold water to ensure that their crops grew from seed to, harvest. Water could be carried in buckets from the river, but if the rain stopped and there was a lengthy drought, the crops would die.
The problem of over-reliance on natural water supplies was solved by creating artificial means of bringing the water to the fields. The water was either diverted from a major river through canals and drainage ditches that flowed alongside the fields, or it was stored in reservoirs and ponds that were refilled in times of flood, and distributed from these. The effect of this irrigation was to extend the area of fertile land from just a narrow strip on either side of a river to a wide band that could be several miles across. Having more irrigated land resulted in more crops, and thus the ability to support a rising population.
