Simplify the following text for a Grade 11 native English-speaking person.
Original: To the west , a series of large , winding river systems including the Mitchell , Coleman , Holroyd , Archer , Watson , Wenlock , Ducie and Jardine catchments empty their waters into the Gulf of Carpentaria .
Simplified: To the west , large , winding river systems including the Mitchell , Coleman , Holroyd , Archer , Watson , Wenlock , Ducie and Jardine flow into the Gulf of Carpentaria .