Water-related energy accounts for around one-quarter of California's energy use. Most of the influence is within cities. This project aimed to identify research and policy needs associated with managing energy related to urban water. A workshop was convened with diverse representation from water and energy sectors in federal (US), state (California) and municipal governments, research and regulatory agencies, universities, utilities, not-for profit and private sectors. The workshop established a vision of future cities, including elements of success, research needs and barriers. A subsequent on-line survey was used to estimate the potential, effort and ‘potential-to-effort’ ratio of each suggested element. First suggested steps in the roadmap include: development of educational programmes, combined standards, guidelines, funding and planning for water and energy efficiency, improved understanding and management of factors motivating consumers, and improved methods to quantify and track targets of ‘water-related energy and related greenhouse gas emissions’. The ‘roadmap’ could help streamline future effort and sequencing action. The authors note and reflect on the importance of representation at such a workshop, and an effort is made to understand sources of variability in viewpoints. The semi-quantitative method used could have relevance to wider resource management issues and complex problem resolution.