I'm working on a project that will be in the public domain/ creative commons. I would like to find watershed/drainage basin data for Central and South America.
WWF provides HydroSHEDS, which covers the planet very well. Unfortunately WWF provides the data under a license. It's free, but there are terms and clauses on derivative work which would undermine goal of having the project be public domain/ CC.
Short of being able to find other national or NGO sources, the only option seems to be building the polygons from the same SRTM topo data.