Broadly defined a beneficial use is a “lawful appropriation that employs reasonably efficient practices to put water to use without waste.” The original Constitutional meaning held that water must be diverted from the natural stream to be put to use, unless it was put in storage. Any water left in the stream was considered a waste. Only the State can hold an in-stream flow right for the environment, and only governmental entities such Counties or Municipalities can hold in-stream recreational rights. All private rights must be for diverted water.
The State Legislature establishes what a beneficial use is. Initially irrigation, mining, industrial application, stock watering, domestic and municipal use, and other non-wasteful, historical economic activities were recognized.
Over the years concepts of Beneficial use under the Colorado system evolved and included more and more uses. Eventually even in-stream needs for the environment and recreation were established within the priority system.