NORTH AMERICA

The United States

The United States operates under two major systems of water rights: riparian doctrine in the East and prior appropriation in the West. The quantifying of Native American tribal rights and their integration into these systems is becoming more important. The acequia system found in the Southwest is one of a few hybrids. It was inherited from the Spanish, who brought it from the Arab world.

The United States of America is a federal system. The states are sovereign entities and they have control over water resources. Like other large countries in the world, river basin operations and organizations revolve first around the alignment of powers among these sovereign entities, which rarely fit river boundaries. Second, they revolve around the exercise of bureaucratic power within the federal and state governments. Multiple agencies work with water usually within their own mandates and sector.

However, there are major federal interests affecting water distribution and use. In fact, one of the United States' earliest court decisions was confining the power of the federal government to regulate commerce involving water navigation. Beyond interstate commerce, federal control over water has been established in a variety of areas, such as for emergencies, flood control, irrigation, public health, environmental issues, and fish and wildlife. Many of these interests have been institutionalized in numerous federal agencies, which present a formidable coordination task.