Floods and drought
The European Flood ALert System (EFAS) - http://floods.jrc.ec.europa.eu/efas-flood-forecasts.html
and the European Drought Observatory (EDO) - http://desert.jrc.ec.europa.eu/.
provide web services for nowcasting and forecasting of floods and droughts, respectively.
Both services are managed by JRC using the LISFLOOD model: http://floods.jrc.ec.europa.eu/lisflood-model.html.
Nutrients and chemicals
The fate and impacts of pollutants in terrestrial and aquatic ecosystems is assessed in the FATE activity: http://fate.jrc.ec.europa.eu/rational/home
More information on the modelling of nutrients and chemicals: http://fate.jrc.ec.europa.eu/modelling/chemicals