In its most basic form, irrigation takes water from an available natural source and diverts it to crops through man-made channels or ponds. The Egyptians had little need for such methods as the River Nile naturally flooded their farmlands every year. They perfected systems that diverted the Nile to feed their crops and deposit its nutrient-rich silt. For those less fortunate, living in harsher conditions, engineering offered the opportunity to improve on these primitive methods. The most effective early techniques involved the building of diversion dams to channel water from rivers into canals.
