Colorado River water

Further, compact delegates distrusted, and in some cases actually feared federal involvement in Colorado River affairs. Arizona v. California opened the door to federal participation. The decision interpreted the Boulder Canyon Act as empowering the Secretary of Interior to act as water master of the Lower Colorado River, to apportion future surpluses and shortages among the states and even among users within the states.

in reference to: Sharing Colorado River Water: History, Public Policy and the Colorado River Compact (view on Google Sidewiki)