Nearly all of the streams in Mecklenburg County start in Mecklenburg County.  However, they don't all flow in the same direction.

Streams in the western two-thirds of the County flow to the Catawba River.  Streams in the eastern third of Mecklenburg flow to the Yadkin River, then the Pee-Dee.  Both rivers eventually flow into the Atlantic Ocean, but take very different paths.