I’m trying to gather climate timeseries data for a project focussed on Madagascar. I found this source, the World Bank’s Climate Change Knowledge Portal. That offers climate data by “watershed”, e.g. the northern-most area for Madagascar is coded as MDG.15041750. That’s the white area shown on their map

When I asked for the reference shapes, they said they use “HydroBasins v4” and gave a link to this site. I tried Hydrobasins Level 04, but the codes don’t match, e.g. the northern-most area for Madagascar is coded as HYBAS_ID: 1040036870. I also tried LEVEL 05 and 06 without finding any matches.
Does anyone recognise their coding system as part of HydroSHEDS?