Which of these is a policy or recommendation that ADWR would be likely to oversee?

The choice regarding a policy that allows for no new groundwater drilling in Phoenix is likely correct because it aligns with the Arizona Department of Water Resources (ADWR) mandate to manage and protect the state's water resources effectively. In particular, Phoenix is located in a region that has faced significant challenges related to groundwater depletion due to its rapid urban growth and increasing water demand.

By overseeing a policy that restricts new groundwater drilling, ADWR can work toward sustainable water management practices. This would help mitigate the risks of over-extraction of groundwater, promote water conservation, and encourage the use of alternative water sources. In areas where groundwater supplies are limited or depleted, policies that restrict further drilling help safeguard existing supplies for current users and future generations.

In contrast, other options, such as encouraging groundwater drilling or promoting new well projects, might exacerbate the issue of water resource depletion, and the recommendation to reduce water use by a specific percentage is more of a goal than a specific policy ADWR would craft. Therefore, the oversight of a policy prohibiting new groundwater drilling would represent a proactive measure towards sustaining water availability in a major urban area like Phoenix.