<Tr> <Td> 8 </Td> <Td> Rybinsk Reservoir </Td> <Td> Russia </Td> <Td> 4,580 </Td> <Td> 1,770 </Td> <Td> </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Caniapiscau Reservoir </Td> <Td> Canada </Td> <Td> 4,318 </Td> <Td> 1,667 </Td> <Td> </Td> </Tr> <Tr> <Td> 10 </Td> <Td> Lake Guri </Td> <Td> Venezuela </Td> <Td> 4,250 </Td> <Td> 1,640 </Td> <Td> </Td> </Tr> <Table> <Tr> <Th_colspan="6"> The world's ten largest reservoirs by volume </Th> </Tr> <Tr> <Th> Rank </Th> <Th> Name </Th> <Th> Country </Th> <Th_colspan="2"> Volume </Th> <Th> Notes </Th> </Tr> <Tr> <Th> km </Th> <Th> cu mi </Th> </Tr> <Tr> <Td> </Td> <Td> Lake Kariba </Td> <Td> Zimbabwe, Zambia </Td> <Td> 180 </Td> <Td> 43 </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Bratsk Reservoir </Td> <Td> Russia </Td> <Td> 169 </Td> <Td> 41 </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Lake Nasser </Td> <Td> Egypt, Sudan </Td> <Td> 157 </Td> <Td> 38 </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Lake Volta </Td> <Td> Ghana </Td> <Td> 148 </Td> <Td> 36 </Td> <Td> </Td> </Tr> <Tr> <Td> 5 </Td> <Td> Manicouagan Reservoir </Td> <Td> Canada </Td> <Td> 142 </Td> <Td> 34 </Td> <Td> </Td> </Tr> <Tr> <Td> 6 </Td> <Td> Lake Guri </Td> <Td> Venezuela </Td> <Td> 135 </Td> <Td> 32 </Td> <Td> </Td> </Tr> <Tr> <Td> 7 </Td> <Td> Williston Lake </Td> <Td> Canada </Td> <Td> 74 </Td> <Td> 18 </Td> <Td> </Td> </Tr> <Tr> <Td> 8 </Td> <Td> Krasnoyarsk Reservoir </Td> <Td> Russia </Td> <Td> 73 </Td> <Td> 18 </Td> <Td> </Td> </Tr> <Tr> <Td> 9 </Td> <Td> Zeya Reservoir </Td> <Td> Russia </Td> <Td> 68 </Td> <Td> 16 </Td> <Td> </Td> </Tr> </Table>

Why are reservoirs built along a river's journey