Oil and water, and the science and technology used to harness them, have long been at the heart of political authority in Saudi Arabia. Oil's abundance, and the fantastic wealth it generated, has been a keystone in the political primacy of the kingdom's ruling family. The other bedrock element was water, whose importance was measured by its dearth. Over much of the twentieth century, it was through efforts to control and manage oil and water that the modern state of Saudi Arabia emerged.

The central government's power over water, space, and people expanded steadily over time, enabled...