Al-Hasa Oasis changed in many respects during the Faisal decade — in urban development, administration, economics and population distribution. This chapter presents a radical, perhaps even a revolutionary change in the irrigation patterns of the oasis of al-Hasa in Eastern Arabia, achieved as the result of direct action by the Saudi Arabian Government during the Faisal decade. Beginning in the mid-1960s the Saudi Arabian Government decided to attempt stopping the deterioration of al-Hasa oasis by completely dismantling the old water distribution system and substituting it with a modern one. By all standards of measurement the oasis of al-Hasa is truly extraordinary. Al-Hasa has close to five hundred springs, but approximately two thirds are privately owned, producing only enough water to irrigate individual gardens. As a 'true' oasis, al-Hasa is entirely surrounded by desert; mostly sand-dunes to the East and North and a rather flat, thin sand mantle over a limestone floor to the West and South.