Decreasing availability of in-situ river monitoring data can be met with increasing availability and quality of satellite altimetry data over rivers. CryoSat-2 is an altimeter mission launched in 2010 by the European Space Agency (ESA). With its unique drifting orbit, common procedures of working with satellite altimetry data over rivers cannot be easily applied. This work presents a way of informing a hydrologic-hydrodynamic model of the Brahmaputra River with CryoSat-2 altimetry. For one, CryoSat-2 data with its high spatial resolution was used to calibrate water levels in the 1D hydrodynamic model. For the other, a data assimilation framework was developed and applied, showing promising results for assimilation experiments with real and synthetic CryoSat-2 data.