Simplify the following text for a Grade 4 native English-speaking person.
Original: The Lachlan River flows west and then south , terminating in the Great Cumbung swamp near Oxley ( between Hay and Balranald ) .
Simplified: The Lachlan River flows west and then south , finishes in the Great Cumbung swamp . This swamp is near Oxley between Hay and Balranald .