The objective of this article is to present the process of municipalization, understood as the internalization of management, of the water supply service that is taking place in the city of Terrasa, after 75 years of indirect management through concession, whose contract expired on December 2016. I first discuss some aspects of public services managements that, if practiced, could contribute to overcome the difficulties experienced by Terrasa, to facilitate the government of the services, and, if it should happen, to proceed with a process of municipalization. The legal Spanish framework imposes limitations and requirements to introduce changes in the forms of management of public services. Taking these into account, in addition to the model of administrative process and its practical implementation in Terrasa, it was found that the most efficient and sustainable form of management is direct management though a public local company. The administrative process to implement the change was finally approved on 22 March 2018, World Water day, which opens a new stage in the process of creating the local public company and the start of the provision of service by the municipality, which is set for 10 December 2018. This issue has been published as Volume 5, Number 1 of the WATERLAT-GOBACIT Working Papers (http://waterlat.org/publications/working-papers-series/). This is a special series of the Working Papers, titled “The struggle for democracy in Spain: grassroots initiatives to defend essential water services as a common good”, José Esteban Castro (Ed.), Edurne Bagué (Org.).