《水经注·卷十二》
沟水从泽地分支流出，往东流经琢县老城南面，又往东流经汉侍中卢植墓南，又分散东流，形成沼泽，就是督亢泽，向北转弯注入桃水。
其水自泽枝分，东径涿县故城南，又东径汉侍中卢植墓南，又东，散为泽渚，督亢泽也。北屈注于桃水。
The canal water flows out of the marsh and splits into several branches, and flows east through the area south of Taocun's old city, then east through the tomb of Han dynasty official Lu Zhi, and then splits up again and flows east, forming a marsh, called Dukan marsh, which turns north and flows into Tao River.