The search for water is essential to societies living in arid or semi-arid environments. Every time man tried to control his food production, he had to build up his own agricultural territory. The adoption or the discovery of a technique for water supply has always brought about the development of new survival strategies. Successive hydraulic installations have thus become part of the landscape. This is shown in the different contributions on water strategies put together in this publication, where it is also confirmed that large networks could have been created by communities or family groups. The water supply networks outline the social geography of those that installed them. Their management is an important factor for the cohesion and social structure of the communities, a prestige factor to individuals wishing to assert themselves, and sometimes even a tool for power. The strategies for the acquisition of water appear as so many factors of complexity and hierarchy that can change the ways of life and overturn the structures of the society.