Semantic search
- Meuse Basin
- Mino Basin
- Mira Basin
- Mirim Lagoon Basin
- Mississippi Basin
- Mius Basin
- Moa Basin
- Moho Basin
- Mono Basin
- Moselle Basin
- Motaqua Basin
- Murgab Basin
- Murray-Darling Basin
- Naatamo Basin
- Nahr El Kebir Basin
- Narmada River
- Narmada River Basin
- Narva Basin
- Negro Basin
- Nelson-Saskatchewan Basin
- Neman Basin
- Neretva Basin
- Nestos Basin
- Niger Basin
- Nile
- Nile Basin
- Nile River
- Nyanga Basin
- Ob Basin
- Oder (Odra) Basin
- Oder Basin
- Ogallala Aquifer
- Ogooue Basin
- Okavango Basin
- Olanga Basin
- Orange Basin
- Orinoco Basin
- Oued Bon Naima Basin
- Oueme Basin
- Oulu Basin
- Oyupock (Oiapoque) Basin
- Pakchan Basin
- Palena Basin
- Pandaruan Basin
- Pangani Basin
- Parana
- Parnu Basin
- Pascua Basin
- Pasvik Basin
- Patia Basin