Purpose of Beijing and Hangzhou Grand Canal

It was something that was greatly feared by the people, the ancient Chinese people in the Xia Dynasty (often referred to by other tribes as the Hua xia) who lived along its banks. The river was both a life-giver and a life-taker. Naturally, Xia wished to maximize the former and minimize the latter. Therefore a leader who could offer to minimize the terror of an overflowing river – which was a parameter beyond the control of the individual, while there were many parameters involved in a successful harvest that was indeed within the control of the individual – would instantly have a following.

Not surprisingly, leaders came and went, because it was not easy to tame such violent forces of nature. What had been tried, time and again but with little success was damming the river, for no matter how high the protective walls and no matter how sturdy they appeared to be built during their construction, when the floodwaters came, and in Biblical proportions, it must be said, the dikes and dams were swept away as were they made of matchsticks and mud. A new leader promising a better mousetrap hired a minister to find a better solution to the problem of flooding; the previous Minister for Waterworks, a certain Minister Gun, had in fact been held responsible for the violent floods during his tenure, and ended up paying the ultimate price for his 9 seasons of failure: he was executed!

The new Minister for Waterworks, Minister Yu, decided to try something else: out were dams; in were diversionary canals, i.e., canals that could divert the overflow elsewhere, as well as serve as reservoirs in their own right. The new flood control strategy worked so well that Minister Yu became a national hero, and, as so often happens – from Roman times down to the present – the famous general who wins the war becomes such a hero that he ends up scoring his boss' job, which is precisely what happened in the case of Minister Yu, who became Emperor Yu, or Yu the Great.

A Real-world Example of Minister Yu

It was Sun Shu-Ao (BCE ca.630-ca.593), a minister serving in the government of Chu State during the Spring and Autumn Period of the Eastern Zhou Dynasty. Sun eventually became Prime Minister and was commissioned to create various waterworks: irrigation canals, dams and reservoirs. Most of the waterworks of PM Sun were focused on improving existing and/or extending agricultural land use to new areas.

For example, a dam might be designed to lightly flood a valley (with numerous reservoirs and sluices to regulate the water level) so that rice could be grown there. Reservoirs could hold water to be used to get through shorter drought periods, while canals could divert water to specific locales instead of having to flood entire areas. PM Sun made use of all of these tools to address the agricultural problems he faced. Much later, Sun Shu-Ao was recognized as China's first hydraulic engineer.

Chu State sat in the heart of ancient China's "breadbasket" that lay between the Yellow and the Yangtze Rivers – and, additionally, the Huai River ran through it. (An interesting observation, not related to the discussion at hand, but of interest to the armchair historian – of which there are surely a few among you? – is that the last two of the remaining Zhou Dynasty states by the end of the Warring States period, the Qin and Chu States, were not only large states (they had each absorbed lesser states), but were each situated on the perimeter, compared to the other states, surely thus decreasing their vulnerability to attack. And speaking of vulnerability, given the importance of rivers in warfare during the period, and given the fact that all of China's major rivers in this part of the country flowed from west to east (in particular, the Huai River), it was almost inevitable, caeteris paribus, that Qin State would be victorious over Chu State, it being a lot easier to slip downstream than upstream.)

One of the huge waterworks created by PM Sun is the reservoir known alternatively as Si-Si Pei, Shao Pei (Peony Dam), and Que pi hu (Que pi hu lake [芍陂湖]. This ancient reservoir exists still, though it is known today as Anfeng Tang (Anfeng Reservoir), after extensive restoration (the reservoir was clogged with silt, mainly mud) by the government of the People's Republic of China.

The ingenious practice of diverting the overflow of the Yellow River via flood canals continued down through the Tang Dynasty and Five Dynasties (CE 907-960) period. During these two historical periods, when there was much warring even if there was a certain degree of centralization of power during the Tang Dynasty (the warring was the result of wave after wave of Turkic nomadic invaders arriving from the north, the oldest waves becoming more and more Sinicized over time, therefore the relative peace that ensued during the Tang Dynasty in particular).

The overflows from the Yellow River seemed to increase, not decrease, requiring the extensive dredging and repairing of the canals (their banks required fortifying with tree trunks of saplings (young trees) lashed to stones with ropes, the whole lashed together with more ropes, creating a fortifying wall of wood that helped to reduce the incidence of erosion). Due to the warring, the canals also served as connective waterways for the transport of much-needed grain to the capital, Kaifeng, from the grain-rich valley of the Yangtze River northward via the Shanyang Canal (later to be known as the Yangzhou Canal) to Huai'an, via the Si River from Huai'an to Pengcheng (present-day Xuzhou) and finally via the Bian Canal (note that both the Shanyang Canal and the Bian Canal were originally referred to as rivers, due to their meandering nature).

After the somewhat troubled Five Dynasties and Ten Kingdoms period, the warring between the Han Chinese and the nomadic Turkic tribes broke out even more, in fact, soon after the emergence of the otherwise unifying Song (CE 960-1279) Dynasty, though the unity quickly broke down, such that the Northern Song capital, Kaifeng, was eventually overrun by the invaders, with the Han Chinese remnants of the Song Dynasty regrouping farther south, under the flag, as it were, of the Southern Song (CE 1127-1279) Dynasty, whose capital became the city of Lin'an, or present-day Hangzhou.

This move did not end the need for flood control, for the Yangtze River was at times almost as prone to flooding, if not more so, than had been the Yellow River. Thus the Han Chinese tradition of flood control via the construction of diversionary canals continued, though on the Yangtze River instead. These flood control measures would naturally continue on both drainage systems during most of the remainder of China's dynastic period, with greater zeal during periods of peace, i.e., during periods of unification, which was largely the case after the emergence of the Yuan (CE 1279-1368) Dynasty.

Of course, parallel with the notion of flood canals, China continued to build dams on rivers as a way to contain them, or so it was hoped. At least the dams could contain smaller rises in river levels. Unfortunately, attempts at building very large dams proved a fiasco (alas, this lesson may be repeating itself today on the prestigious Three Gorges Dam, admit PRC officials), for when the large dams were eventually washed away, the amassed volume of water released created devastation on a Biblical scale, almost as devastating as a tsunami.

Ancient Chinese Waterworks

Two famous, ancient – but still functioning – Chinese waterworks, one a dam and the other a canal system, are:

Dujiangyan Dam – a diversionary canal (irrigation canal) system, originally built in BCE 256 during the Warring States period on the Min River in Sichuan Province, near the capital, Chengdu.

Mulan Dam (Reservoir [木蘭陂]) – originally built in CE 1064 as a dam across the Mulan River in Fujian Province near the city of Putian, and financed by two private citizens of the city of Putian, Lady Qian Siniang and Mr. Lin Chongshi who were inspired by the famous Luoyang Stone Bridge built in CE 1059 in the port city of Quanzhou, another famous Maritime Silk Road port (see the link to the Maritime Silk Road section of the Silk Road article in the "100% Canal" section farther below). (Curiously enough, Putian is the natal city of numerous other famous Chinese women, including Lin Moniang, aka Mazu or Matsu [媽祖], believed to be an incarnation of Guanyin, the sea goddess, or the patron saint of seafarers, as it were).

The dam was soon washed away, though in CE 1075 a new Mulan Dam, this time built during the Xining reign (CE 1068-77) of Emperor Shenzong – and financed by the emperor – was built nearby (the problem with the first dam was judged to be the site itself). Its clever system of sluices permitted water to escape long before a dangerous buildup could occur.