is the highest point of land between them. This dividing line, or divide, causes each basin to be drained by a different river system.
In Texas, there are 23 major river basins that drain into the Gulf of Mexico as illustrated in Figure 4-2. Maps of the river basins can be found in the Atlas of Texas Surface Waters at www.tceq.state.tx.us/comm_exec/forms_pubs/pubs/gi/gi-316/index.html