Final answer:
The doctrine of water usage in Arizona is best described as Western history, with the Newlands Reclamation Act and strain on water resources as key aspects.
Step-by-step explanation:
The doctrine of water usage in Arizona is best described as Western history. Water usage has played a significant role in shaping the settlement patterns and development of the Western United States, including Arizona. The Newlands Reclamation Act of 1902, which created the Reclamation Service, allowed for the distribution of water to arid regions like Arizona, leading to agricultural and urban development. In recent times, the strain on water resources, especially in arid states like Nevada, has become a hot-button political issue.