Urban stormwater systems in cities around the world are challenged by urbanization and climate change, and a range of Stormwater Control Measures (SCMs) are being implemented as solutions to these challenges. We developed a conceptual framework of technological stabilization based on Social Construction of Technology (SCOT) and Transition Science, and conducted 16 in-depth actor interviews as a basis for mapping the historical development of in the two cities. The SCMs applied in Melbourne and Copenhagen are similar, but using a new framework for technological stabilization we identify differences in their application due to different physical, organizational and cultural contexts in the two cities, drought being the main driver during the past decade in Melbourne (1997–2010) and pluvial flooding in Copenhagen (2007-). In Melbourne there is currently a strong integrated understanding of SCMs: after decades of “new technology” development, “testing” and “opportunity” seeking a large degree of “agreement” about stormwater management as a mainstreamed professional practice has arisen. In Copenhagen there are currently multiple conflicting understandings of SCMs and signs of an emerging integrated understanding that offers “opportunities” for further development and implementation. It is clear from Melbourne's history that: successful full scale demonstration projects supported and developed by a wide range of actors helps building a common vision for SCM technologies, supportive policies across several governmental levels provide incentives for implementation, and inclusive actions in the closure process provides a sense of ownership for SCM technologies across disciplines.