Water policies are based on ethical assumptions, and efforts to promote more sustainable policies need to address those underlying values. The history of water policies from 'command-and-control' to more ecological approaches reveals an ethical evolution, but adaptation to climate change will require further ethical shifts. The case of the Santa Fe river in New Mexico (USA) illustrates how values that go unrecognised interfere with sustainable management. Exploring the underlying value dynamics is an essential step in the policy reform process and takes on added urgency in the face of climate change and the need to formulate adaptive water strategies. Bringing the topic of values and ethics into the water policy discourse can help clarify management goals and promote more sustainable practices.