Rivers basins across the world have different social, economic and political conditions, with many of them resulting in the need for water management.
Many of these conditions are the same, but some are specific to a particular river basin.
The Colorado is typical of many river basins. The map below shows its location.
More than a hundred dams have been built by the Bureau of Reclamation and the Army Corps of Engineers for flood control and to create hydroelectricity and store agricultural and municipal water.
They harness the river's widely varying flows to generate a steady water supply.