Q Throughout much of the West, water is a limiting resource with respect to economic growth and development. In deciding who has the right to use the water that is available, the Prior Appropriation Doctrine is frequently applied. Essentially, Prior Appropriation states that whoever was using the water first owns the right to continued use of the water, provided it is put to some beneficial use. Is this a reasonable legal mandate to follow when awarding water rights? Or should whoever can put the water to the “best” use have priority over who was using the water first? How would you decide what the “best” use of water is? When answering these questions, consider the following scenario: A gold medal trout stream flows out of a mountain range near a growing western city into a valley. This supports a commercial guided sport fishing and tourism industry that directly or indirectly supports 22 businesses in the valley (fly shops, outfitters, guide services, lodges, restaurants, etc.) that collectively employ several hundred people. Obviously, this entire industry depends on having adequate streamflow to maintain the trout population. However, cattle-ranching is the oldest industry in the valley. Four ranches with a total beef production of 3000 head annually are located in the valley and are still owned and operated by the descendants of the first white settlers to occupy the valley. During normal years, stream flow is adequate to maintain the trout fishery and irrigate pasture for cattle. During dry years, however, the rancher’s use of their water rights can reduce the stream to a trickle, threatening the continued existence of the trout fishery. Meanwhile, the growing city is looking for new sources of water to support continued growth and economic development, and wants to divert the stream into the urban water supply system. City planners argue that diverting the water to the city would benefit tens of thousands of people both directly and indirectly as a public water supply that would support new growth and economic development. The ranchers argue that they are guaranteed continued use of the stream under Prior Appropriation because their use of the water predates all others. Although the trout themselves have no legal right to the water they live in, the people who earn their livelihoods directly and indirectly from the sport fishing industry argue their rights as water users are important too. What are the successes and failures of Prior Appropriation in this scenario? Who has the best claim to the water? Who could put the water to the best use? Who should get the water? How would you decide?