The Shichahai Lakes

Qianhai and Houhai are two parts of one chain of lakes. Together with Xihai, which lies farther west, they form Shichahai. The name is usually translated as “Sea of Ten Temples”; Qianhai means Front Sea, and Houhai, Back Sea. At the end of the thirteenth century, these names did not yet exist. The body of water was much wider and was called Jishuitan—the Storage Pond.

Grain from the southern regions was then transported to Dadu—the name Beijing bore under the Yuan dynasty. Barges reached Tongzhou, east of the capital. There, the sacks were transferred to carts and pack animals. In autumn, the road turned to mud; donkeys and other draft animals were lost in countless numbers. The final overland stretch cost people and the treasury more than the long voyage from the south.

In twelve ninety-one, Guo Shoujing, the sixty-year-old head of the waterworks bureau, proposed bringing vessels all the way to Jishuitan. Engineering was his service: Kublai Khan, emperor of the Yuan dynasty, assigned him waterworks and expected from him a reliable route for the capital's grain.

There was not enough water nearby. Guo Shoujing chose Baifu Spring north of Dadu and led the water along a route that at first glance seemed strange: first west, along the foot of the mountains, then south, through the Wengshanpo reservoir—today's Kunming Lake in the Summer Palace. A direct route crossed low river valleys, where the flow would have had to be held back by complex structures. Guo Shoujing measured the elevations and proved that, along the roundabout channel, the water would reach the capital on its own. It entered Dadu from the west, filled Jishuitan, and then flowed east toward Tongzhou. The engineer divided the drops between sections with a cascade of locks.

Kublai Khan ordered officials and military commanders ranked below the chancellor to take up baskets and shovels themselves. Guo Shoujing was to direct them: even the highest-ranking participants began digging only after his instructions. Construction continued from the spring of twelve ninety-two until the autumn of twelve ninety-three.

When Kublai Khan returned from his northern residence at Shangdu, he passed Jishuitan and saw that vessels covered the surface of the water. The emperor named the new route the Tonghui Canal—“Universal Benefit”—rewarded Guo Shoujing, and put him in charge of grain transport along the canal. Hauling cargo from Tongzhou along the muddy road ceased. The following year, a separate transport administration was established by the lake; docks, warehouses, and markets appeared along the shore.

In the fifteenth century, Ming dynasty builders incorporated the eastern section of the water route into enclosed imperial territory. Cargo vessels were forbidden to pass through, and the terminal dock was moved outside the city. The shores of the former port were gradually built over and filled in, and the single Jishuitan divided into today's lakes.

At the eastern end of Qianhai, the stone Wanning Bridge survives. Beside it stood the upper lock, which people used to maintain the water level needed by vessels. The lock no longer operates, but the bridge still spans the former outlet of the port, while Qianhai and Houhai occupy the central part of its old water area.