The description of GIS technology of operative space monitoring the passage of flood waters and floods is given. Its results have found practical application in the work of Agency of Emergency Situations. The optical and radar remote sensing data of different resolution are used in the monitoring process, which list is updated by new available remote sensing data. In recent years in system was included on regularly basis data from new optical Landsat-8 and radar Sentinel-1A satellites. Additional information about zones of flooding is obtained in the processing of complex radar data by methods of a radar polarimetry.