Bernard Barraqué, a mining civil engineer and Harvard graduate urban planner, worked first as an urban environment consultant and then increasingly as a researcher and teacher. Recruited to the CNRS in 1988 as an interdisciplinary department in architecture, urban planning and society, he worked 19 years at the Laboratoire Techniques Territoires et Sociétés (LATTS) before joining the CIRED, where he is now Director of Emeritus Research. It analyses in a comparative and historical way, in Europe and in some emerging countries, the reasonable and equitable sharing of water resources, the sustainable management of public water and sanitation services, and the link between the two. His latest project, Water&3E, was funded by the ANR Ville durable, and left a blog available: http://eau3e.hypotheses.org. He is currently reflecting on the nature of water as a common good, and on the history of economics, law, and related public policies.