According to the
"Useful Environmental Maps" page of my website, you can find a map of the DR's basins and sub-basins at this link:
http://www.medioambiente.gov.do/cms/...s/mapa-003.jpg
FYI, a map of the DR's subterranean waters can be found at:
http://www.medioambiente.gov.do/cms/...s/mapa-003.jpg
Hope this helps.