Drought originates from a long period of below-normal precipitations. This precipitations deficiency, what might be called meteorological drought, will have repercussions on different components of the hydrological cycle (soil moisture drought, hydrological drought, etc.) and on human activities (socio-economic drought). In this presentation we study hydrological droughts which affected the Mosel catchment since the middle of the 19th century. These events produce severe low flows and can hence be analyzed through river streamflow. Nevertheless, hydrometric data are rarely available before the 1950s. However, climate data (temperatures and precipitations) records longer series and can hence be used to reconstruct past low flows by using hydrological modelling. Droughts intensity and duration will be characteristize by droughts indices and low flow indices to allow a classification in terms of severity. Development and genesis of hydrological drought will also be analyzed. Relations between precipitation deficiency and low flows are nonlinear and other factors have to be considered: catchment physical characteristics, antecedent conditions, anthropogenic pressures, etc. Last we focus on drought impacts on human activities and measures that have been taken to anticipate and reduce the vulnerability to drought hazard.