Product Assessment with GREAT-ER  |  GREAT-ER Sediment Plug-in Module |  Elbe Calibration & Validation The catchment to be incorporated is limited to the south by the Czechian border, to the north by the barrage of Geesthacht. So the area of concern covers about 90.000 km2 and includes the subcatchments of Schwarze Elster, Mulde, Saale and Havel. This project is sponsored by the UBA (Germany).