 The township is in the Delaware watershed and borders the Lehigh River to the north, which drains Lower Saucon except for the Leithsville area in the extreme south, which is drained by Cooks Creek east into the Delaware River.North-to-south local thoroughfares include Route 378 in the extreme west, Route 412, and Lower Saucon Road in the east.Interstate 78 crosses Lower Saucon east-to-west with access from 412 at the Bethlehem/Hellertown line and Highway 33 in the northeast.