The remote sensing of water quality in lakes and reservoirs has been hampered so far by the lack of appropiate Earth Observation satellites, which combine the sensitivity, spatial and spectral resolution needed for retrieving information on the optically active constituents (OAC) of inland waters. This situation is about to change with the European Sentinel-2 mission (S2), whose first satellite (S2-A) was launched in June 2015 and is already operational, while the launch of the second satellite of the constellation (S2-B) is expected for mid-2016. The Sentinel-2 satellites allow mapping water bodies with a high revisit time (5 days), a spatial resolution of up to 10 meters and have a set of spectral bands suited for retrieving key variables, namely chlorophyll-a concentration (Chl-a), water transparency, suspended solids (SS) or Colored Dissolved Organic Matter (CDOM).