| 100% | ORANGE | 6 | River rising in the Drakensberg mountains that forms the boundary between South Africa and Namibia |
| 46% | AMUR | 4 | River that forms the boundary between Manchuria and Russia |
| 45% | DRINA | 5 | River that forms the boundary between Bosnia and Herzegovina and Montenegro |
| 44% | TWRCH | 5 | River that formed the ancient boundary between Brecknockshire and Carmarthenshire |
| 43% | LIMPOPO | 7 | River forming the border between Zimbabwe and South Africa |
| 43% | RHYMNEY | 7 | River in Wales forming the boundary between the historic counties of Glamorgan and Monmouthshire |
| 41% | LIMPOPO | 7 | River that serves as the border between Zimbabwe and South Africa |
| 40% | SAAR | 4 | River rising in the Vosges Mountains that flows north to the Moselle in Germany |
| 40% | SAAR | 4 | River rising in the Vosges Mountains that flows north to the Moselle River in Germany |
| 39% | EBRO | 4 | River that rises in the Cantabrian Mountains |
| 39% | MORAVA | 6 | River that forms the border between Slovakia and Austria |
| 39% | MEKONG | 6 | River that forms the border between Laos and Myanmar |
| 38% | DRINA | 5 | River forming the boundary between Bosnia and Herzegovina and Montenegro |
| 38% | SAN | 3 | & 15D River rising in the Sierra Nevada that forms a large delta with the Sacramento River near Suisun Bay |
| 37% | MAMORE | 6 | River rising in the Andes that forms part of the Bolivia-Brazil border |
| 37% | DNIEPER | 7 | River rising in Russia near Smolensk that flows south to the Black Sea |
| 37% | RUBICON | 7 | Stream that formed the ancient boundary between Italy and Cisalpine Gaul |
| 37% | DON | 3 | River that rises in the Cairngorm Mountains before flowing east to the North Sea |
| 37% | URAL | 4 | River forming part of the boundary between Europe and Asia |
| 36% | TALLAHATCHIE | 12 | River rising in Mississippi, US, that converges with the Yalobusha at Greenwood to form the Yazoo |
| 35% | EBRO | 4 | River rising in the Cantabrian Mountains |
| 35% | INDUS | 5 | River rising in SW Tibet that flows south-west across Pakistan to the Arabian Sea |
| 35% | MURRAY | 6 | River rising in New South Wales, Australia, that flows into the sea at Encounter Bay |
| 35% | ODER | 4 | River that forms part of the border between Germany and Poland |
| 35% | TAMAR | 5 | River that forms most of the border between Cornwall and Devon |
| 35% | ORINOCO | 7 | River that forms part of the border between Colombia and Venezuela |
| 35% | MOSELLE | 7 | River that forms part of the border between Germany and Luxembourg |
| 35% | DOURO | 5 | River that forms part of the border between Spain and Portugal |
| 35% | RIONEGRO | 8 | River that forms part of the border between Colombia and Venezuela |
| 35% | LIMPOPO | 7 | River that rises in South Africa whose name is derived from Rivombo |