The origins of civilisation are related to agriculture and water control. In Egypt, Mesopotamia, the Indus Valley, in Peru or China, the first civilisations on Earth emerged linked to irrigation in farming arid and semiarid areas. In one way or another, all these civilisations were hydraulic civilisations, and their training and development has been parallel to the development of water control technology. Since these early beginnings, each new civilisation has contributed with its own original development in water management and hydraulic technology .
But water has influenced human culture much more deeply than as a mere challenge for Engineering. Water is a spiritual and almost global element and is present in myth, philosophy and the religions of all cultures on Earth , determining the customs of its use, rituals and social habits'.
Lao Tzu says .
"Eminent goodness moves like water. Water brings good and favours all things, yet it does not seek power. It retires to places that others disdain. Thus it seems near Tao."
In the Vth Century BC, Herodotus, a Greek scholar who is considered the first European historian, said Egypt was a gift of the Nile. Today, it is still so. Egypt is an example of how much civilisation depends on water.
Egypt now has a population of about 85 million people and 90% of them live in the valley and delta of the Nile, of 55,000 km2 which represents only 5% of the territory of the country. Here almost all the fertile land of the country is located, which amounts to 35,000 km2
The Nile valley is a narrow strip of fertile land, this is to say, land which can be irrigated, over a thousand miles long and ten miles wide on average . Two hundred miles from the mouth of the Nile, the river divides into many channels that form the delta, with a maximum width at the coast of four hundred kilometres . The average population density of the Nile valley and delta is about 1400 inhabitants per square kilometre, greater than that of Bangladesh at the Ganges' mouth and delta.