Seattle Public Utilities (SPU) is a municipal water supply, drainage, wastewater, and solid waste management utility in Seattle, Washington. This utility has explored the impacts of climate change and supported climate adaptation work since 1997. Faced with threats such as sea level rise, drought, wildfires, and extreme precipitation events, SPU has worked to “mainstream” climate science throughout its strategic planning, capital investments, management, operations, staffing, institutional culture, and more. This paper provides a descriptive, chronologically ordered account of how SPU’s climate-change-related work has evolved to become an aspect of a broader social and environmental sustainability orientation, aimed at resilience against climate impacts, but also towards improving greenhouse gas emissions reduction, carbon sequestration, water and waste circularity, green infrastructure, ecosystem and species stewardship, green and blue workforce development, affordability, an intergenerational perspective, and environmental justice. We frame this transition as a movement from a core focus on risk management toward a proactive and integrated mode of sustainable operations. While SPU’s journey has been enabled by a co-productive approach to climate services, we speculate on how this model can be broadened and diversified to help SPU pursue their goal of becoming a sustainable organization. It is our hope that this paper sparks reflection and discussion within the climate services community, amongst utilities, municipalities, and policy entrepreneurs that are interested in sustainability.