Lake Hongze  

Lake Hongze which is one of the five major fresh water lakes is situated in the middle reach
0fthe Huaihe River, It is in northwestern Jiangsu Province

Lake Hongze was originally a bay of the Huanghei Sea. As the coast line moved.eastward
and the coastal plain in north Jiangsu extended gradually, it receded to inland to form a
low-lying flat land interceded with rivers and lakes. An earth dike of 15km was built from Laobatou to Wujiadun in the fifth year of Jian'an of the Donghan Dynasty to keep off the 'flood from the Huaihe River. The dike was called Gaojiayan, which was the embryo of the main dike of Lake Hongze. In the 12th year of Daye of the Shui Dynasty, Pofutang, a pool to the right bank of the ancient Huaihe River was renamed Hongzepu ("pu" means "water surface"), and this was how Lake Hongze got its name in the Tang Dynasty. In the reign of Yongle (A.D. 1403 to A.D. 1434) of the Ming Dynasty, Pan Jixun proposed the principle of "Turning the water from turbid to clear by storing it and supplementing the Grand Canal", thus the bottom of Lake Hongze silted up gradually and the lake surface enlarged. To ensure the shipping of the tributes to the emperor through the Grand Canal and to prevent the tomb of the first emperor of the Ming Dynasty from getting submerged, the Gaojiayan Dike was raised repeatedly, and was extended from Laobatou to Jiangba; thus the Huaihe River was forced to go through Qingkou outlet so that it could wash off the silt from the Huanghe River. In the 8th year of Wanli (A.D. 1580) of the Ming Dynasty, a 10kin long upright wall of stonework was built on the Gaojiayan Dike with five overflow dams and culvert. The construction continued and the main dike of Lake Hongze Was not completed till the 16th year of the reign of Qianlong of the Qing Dynasty. The dike raised the water level of Lake Hongze to become a lake with a fairly large capacity for flood storing and discharging. In the first year of Xianfeng, the dike was broken beyond repair at Sanhekou, hence the Huaihe River changed its course to flow through the break at Sanhe and into the Changjiang River through Lake Gaobao.