《水经注·卷三》
定水发源于该县南山的定水谷，往东流经定阳县老城南边。
水西出其县南山定水谷，东径定阳县故城南。
The source of the Ding River is in the Ding Shui Valley of Nanshan, the county seat, and flows east through the south of the old city of Dingyang County.