Placement of stations
It would be good to be able to select a sub-set of stations in the gauging stations and structures files. One possibility would be for instance to limit to locations (especially for the GRDC gauging stations) which have data over a given period. For that we would need to have the period of data coverage in the gauging metadata file. Then in the run.def file we could specify the period over which we expect to run and thus exclude all the locations which do not have observations for that period.