Adopted Stormwater control measures (SCMs) for more than 30 years. These facilities include both source control facilities (rain garden, swales, green roofs...) and catchment scale facilities (ie. wet or dry retention or infiltration basins, wetlands...). Since their emergence, they have proved their efficiency on a hydrological point of view, but some questions still remain about their ability to retain urban pollution. After several decades of operations, there is, however, a growing concern regarding the long-term performance of such facilities. Thus depending on the management of these systems, both hydrological and environmental performance may change over the years (ie. clogging, decrease of retention capacity due to sediments accumulation). It is necessary to develop an effective framework to ensure the operating activity of maintenance and the asset management on long-term management of SCMs. Moreover, these issues may be a hard topic for municipalities, due to the various functions SCMS have to ensure, on a technical point of view (i.e. hydraulic/hydrological and environmental functions) but also because they bring a social point of view (landscape amenities, vegetation, meeting point in the city, walking and playing area...). Asset management of SCMs will concern firstly an exhaustive inventory of SCMs taking into account any available descriptive characteristics, and then a study of their maintenance practices and ageing feedback. Both maintenance practices and management costs differ from one city to another. Costs are even often poorly known. Better knowledge of these practices is expected both for both municipalities operational needs and research studies about SCMs asset management. The paper focuses on public domain SCMs and describes the methodology adopted to investigate the maintenance practices of these facilities and the main costs related to their management. As the aim was to have on-site results, two French cities have been chosen: Nantes and Strasbourg.