A a part of my PhD research, related to the setup of coupled hydrological/hydraulic models using open data at sub-100m resolution and at a global scale, I'm validating how good / bad is water represented in OpenStreetMap. At present, my study area is limited to Murray-Darling River Basin, but eventually it will be rolled-out to the whole Earth. I use Google Earth Engine and a bunch of open-source tools, like PCRaster, GDAL, Fiona. The idea is to perform most of the analysis in the Cloud.
The methodology includes the use of SRTM 30m, Height Above the Nearest Drainage (HAND), 30m resolution, HydroBASINS and LANDSAT 8 datasets.
Daily routine usually looks like this: