The Daliao River proper is formed from the confluence of three rivers at the border between Anshan's Haicheng city and Panjin's Panshan County, after where it runs a length of 94 kilometres (58 mi) covering a catchment area of 1,926 square kilometres (744 sq mi), before coursing in meanders southwest and draining into the Liaodong Bay just west of Yingkou.
The principal river of southern Northeast China, the Liao River, historically bifurcates into two distributaries near the Liujianfang Hydrological Station (六间房水文站) at Xinkaihe Town (新开河镇) of Anshan's Tai'an County, forming the Liao River Delta.
However, the low elevation and the flat, waterway-rich (and often rerouting) topography of the Liao River Delta region created a huge problem in flood control.
During monsoon seasons the storm surges from the Bohai Sea could go as far inland as the Trident confluence, and when meeting the voluminous upstream water from the Liao River, would frequently exceed the capacity of river channels causing massive spill-over flash floods.
This flood risk particularly threatened the cities of Yingkou (which is immediately adjacent to the Daliao River mouth and home to 2 million people) and Haicheng (which has over 1 million residents).