Dānyáng

Danyang lies on the Grand Canal between Zhenjiang and Changzhou. The canal crosses higher ground here, and its waters could become too shallow for grain boats in the dry season. Nearby Lake Lian served as a reservoir, its level higher than the canal and its sluices able to release water when navigation required it.

Officials repaired the lake's embankments and gates repeatedly under the Ming. A local account describes closing the gates at Lücheng and Benniu while water from the lake filled the canal, allowing a line of grain boats to proceed toward the Yangtze. Changes in the timing of transport later reduced demand for stored water, and parts of the lake were turned into fields, making restoration a matter of debate when winter navigation again became difficult.