Since prehistoric times, agriculture in Egypt depended on waters from the Nile River and its steady annual flooding of the Egyptian lands, providing it with water and silt. Thus, the land was irrigated annually in a regular way known as "beds" irrigation, which is a system dividing the agricultural land into beds by mud barriers. The water flows into the beds through canals. Each canal carries water to about eight beds, one after the other. In this way, the lands nearer to the river banks have a bigger share of water than the lands farther away. Eventually, Egyptians advanced to artificial irrigation. It aims at keeping the extra unneeded water left after the flood in the beds near the river banks to use it for watering the farther beds, which the flood water does not reach. This was accomplished through digging a series of canals and bridges. Artificial irrigation was considered an Egyptian achievement that required the people's and government's cooperation and persistence.
Since the stabilization of the central government, Egyptians annually recorded the Nile water level and registered it in official records. The oldest record for the flood levels is found on the Palermo stone from the Fifth Dynasty, on which 63 Nile water levels were recorded. This measurement of water levels continued to be used and developed until 715 AD when the Arabs built the nilometer, or the Roda measure, named for the island it was used on. This measurement was in use until the early twentieth century. Monitoring the Nile water level had a great effect on estimating the taxes and the area of land that could be irrigated in the year. After each flood, the regions were responsible for managing the canals, while measuring the land and recording the water levels were carried out on the national level.
In the Ptolemaic period, Greek temple records presented each region as an economic unit, and referred to the name of the canal which irrigates the region, the cultivated region which is located on the river's banks and is directly irrigated with its water, and the lands located on the region's border that could be reclaimed. The beds irrigation system allowed cultivating one winter crop; while in summer, the only lands that could be cultivated were the high lands away from the flood. Thus, when the Egyptians invented tools to lift water, such as the shaduf, they were able to cultivate two crops per year, which was considered a great advance in the field of irrigation. The shaduf was invented in the Amarna period and is a simple tool which needs two to four men to operate. The shaduf consists of a long, suspended pole weighted at one end and a bucket tied at the other end. It can lift about 100 cubic meters (100,000 liters) in 12 hours, which is enough for irrigating a little over a third of an acre.
In the Ptolemaic era, the waterwheel was invented to lift water. It is a huge wheel with pottery jars fixed around its circumference. The waterwheel plunges into water then turns to lift four to six cubic meters of water. The waterwheel can lift 285 cubic meters (285,000 liters) of water in 12 hours.