Limitations of satellite radar altimetry for operational hydrology include its spatial and temporal sampling as well as measurement problems caused by local topography and heterogeneity of the reflecting surface. In this study, we develop an approach that eliminates most of these limitations to produce an approximately 3 day temporal resolution water level time series from the original typically (sub)monthly data sets for the Po River in detail, and for Congo, Mississippi, and Danube Rivers. We follow a geodetic approach by which, after estimating and removing intersatellite biases, all virtual stations of several satellite altimeters are connected hydraulically and statistically to produce water level time series at any location along the river. We test different data-selection strategies and validate our method against the extensive available in situ data over the Po River, resulting in an average correlation of 0.7, Root-Mean-Square Error of 0.8 m, bias of 20.4 m, and Nash-Sutcliffe Efficiency coefficient of 0.5. We validate the transferability of our method by applying it to the Congo, Mississippi, and Danube Rivers, which have very different geomorphological and climatic conditions. The methodology yields correlations above 0.75 and Nash-Sutcliffe coefficients of 0.84 (Congo), 0.34 (Mississippi), and 0.35 (Danube). Maillard et al., 2015]. Such studies were motivated to a large extent by the premise that satellite altimetry may fill the gap left by the decline of gauge stations database. Surprisingly, other hydrological data like discharge are available in the open domain globally to a larger extent than in situ water level data. Since it cannot realistically be expected that the distribution and availability of global in situ water level stations will be improved in the future, of course with regional exceptions, research on the use of geodetic satellite data needs to be expanded. It is expected that time series from individual altimetric missions over most rivers are of poor quality, due to the neighboring topography and the heterogeneity of the reflecting surface. Therefore, the time series from individual missions often carry uncertainties and contain data outages, which limit the operational use of altimetry for improving the global river water level databases. As a result, these limitations inhibit also the operational use of altimetric water level into hydrological and hydrodynamic models [Alsdorf et al., 2007].