At the time of the British Conquest of Palestine (1917) the Negev’s water resources were little known. During the British mandate (1920-1948), the Negev desert turned to a major policy issue between the Bedouins, the Zionist institutions and the colonial power, due to the successive waves of Jewish migration to Palestine. Critical to the desert’s development, water is sought from the 1930s to determine if this arid space, representing almost half of the surface of Palestine, had the capacity to accommodate the settlement of sedentary Jewish populations. This article focuses with the different steps of British and Zionist search for water resources and enlightens the Zionist land strategy in the desert before the outbreak of the Second World War. This article analyses the Bedouin’s hydraulic techniques and engineering and their transformation by the Zionist institutions.