In 2008, the government of the Popular Party in the Community of Madrid announced its intention to privatize the Canal de Isabel II, a public company responsible for bulk water supply and wastewater treatment services in the Region, despite its highly satisfactory technical, social and economic results. The citizens’ response to this decision was immediately articulated through a Platform against the Privatization of the Canal de Isabel II, which organized its activity around three fundamental axes: denunciation and mobilization, citizen incidence, and political and institutional incidence. Although initially the Platform focused on the defence of public ownership of the Canal, as the process moved on it started to develop a proposal for a management model that is 100 percent public, participatory, consistent with the human right to water, transparent and accountable. 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.).