A hydraulic empire, also known as a hydraulic despotism, hydraulic society, hydraulic civilization, or water monopoly empire, is a social or government structure which maintains power through control over water. It arises through an ecological need for flood control and irrigation, which requires central coordination and a specialized bureaucracy. The term was promoted by Karl August Wittfogel's book Oriental Despotism: A Comparative Study of Total Power (1957).
Often associated with these terms and concepts is the notion of a water dynasty. This body is a political structure which is commonly characterized by a system of hierarchy and control often based on class or caste. Power, both over resources (food, water, energy) and a means of enforcement such as the military, is vital for the maintenance of control.