Simplify the following text for a Grade 5 native English-speaking person.
Original: The Niger River is a relatively `` clear '' river , carrying only a tenth as much sediment as the Nile because the Niger 's headlands are located in ancient rocks that provide little silt .
Simplified: The Niger River is quite a clear river . It has only 10 % as much sediment as the Nile because the Niger 's source is in very old rocks that have little silt .