Wetland ecosystems hold an important part of theworld’s biodiversity and are complex social-ecologicalsystems. Aiming to understand interdependencies amongtheir components and to define management policies, thesocial-ecological trajectory of Oussudu lake – a wetlandof Pondicherry region in South India – was reconstructedand analysed. During the last decades, this wetland hastransformed from an irrigation tank to a lake to caterbiodiversity conservation and recreation. Theenvironmental history highlights a governance changethat has contributed to “black boxing” the wetland’sfunctional environment and to conceal major waterissues at regional and local levels. This study emphasizesthe importance of implementing an approach thatcombines the management of this urban lake commonswith a multi-scalar, socio-ecological and multistakeholderanalysis. A trade-off on the seasonal waterregime between different users - including fauna andflora - has to be found.