Storm water management appeared in the 1970s to both lessen the risks generated by urbanization and optimize centralized urban water treatment systems. To what extent is the sanitation LTS destabilized by the growing number of alternative solutions to the dominant “end-of-pipe” storm water treatment being experimented in new urban projects? We analyse the ongoing process as a "dynamic status quo" between a dominant socio-technical system and a set of innovations diffused by decentralised solutions. The underlying idea is to simultaneously take into account the reconfiguration process of LTS and the continuous process of innovation and change that characterizes the alternative solutions. The diffusion of decentralised solutions does not radically change the socio-technical regime, but instead provides strong evidence of the progressive transition of the sanitation infrastructure.