Simplify the following text for a Grade 5 native English-speaking person.
Original: The Senegal River , or SÃ nÃ gal Fleuve , considered a sweet water river , is a 1790 k long river in West Africa , that forms the border between Senegal and Mauritania .
Simplified: The SÃ nÃ gal River is a river in West Africa . It is 1790 km long and is the border between Senegal and Mauritania .