Despite the increasing push towards collaboration between the natural and social science, little is still known about work at disciplinary boundaries. How does work actually take place at disciplinary boundaries? In the literature, the topic is often addressed in hierarchical terms and an on the basis of fundamental epistemological differences. In this contribution I apply on autobiographical notes to give account of my own experience of collaboration with urban hydrologists on a project aiming to assess the performances of devices for the treatment of urban runoffs. While the work among disciplines in the project is framed as separation, I wish to suggest a more critical perspective on work at disciplinary boundaries by introducing how I became entangled with urban hydrology practice. By applying on Practice-based studies, I give account of my own apprenticeship in urban hydrology through the selection of attention on instrumenting processes, the participation to a heterogeneous community of practitioners, the encounter with these devices materially and the development of aesthetic skills on urban infrastructures. So, I bring the attention on the work at disciplinary boundaries not as cognitive work but as situated and sensible knowledge and as the development of a “way alongside” (Latimer, 2019). I claim this does mean to overcome epistemological differences but rather to let emerge alternative narratives on the same object/practice and to give life to science.