Guangtong Dam Built in 1512

Background

The gazetteer records that in 1512 Suzhou and Changzhou petitioned for a dam at Guangtong on grounds of flooding. The request came from those prefectures and was referred to the provincial authorities, which shows that what was at issue was the water between upstream and downstream, not a matter for Lishui alone.

Time and place

The dam was built in 1512 at Guangtong, the place where sluices had been set up in 1403 with an officer to manage the holding back and release of water.

Guangtong passed to Gaochun when Gaochun was detached in 1491. The Du Shi Fang Yu Ji Yao, juan 20, records that Guangtong is "commonly called Dongba", and traces its water to the Xu River opened in the Spring and Autumn period on Wu Yuan's plan and to the five Lu Yang weirs built by Tai Meng at the end of the Tang; the Qianlong Jiangnan Tong Zhi, juan 25, says "Guangtong, fifty li east of Gaochun County, adjoining the Liyang border, the site of the old Dongba". Both identify Guangtong with the later Dongba, confirming what this entry refers to. On the dating, however, the gazetteer assigns the works to 1512, while the Ji Yao (as quoted at second hand by Fudan CHGIS) dates the stone sluice to "the middle of the Hongwu era" and the rebuilding as an earthen dam to "the beginning of Yongle".

What was done

七年壬申，苏、常等郡以水患奏请筑广通坝。事下抚臣议，加筑高厚三丈，杜塞二闸，厉其禁勿开。先是有闸可以蓄泄，至此水患遂永贻于溧矣！ — Kangxi Lishui County Gazetteer, 卷之一·邑纪·七年壬申

Translated: In the seventh year, Suzhou, Changzhou and other prefectures petitioned on grounds of flooding for a dam to be built at Guangtong. The matter was referred to the provincial authorities, and the dam was raised three zhang in height and thickness, the two sluices were sealed and their opening strictly forbidden. Previously there had been sluices by which water could be held back and released; from this point the flooding was permanently bequeathed to Lishui.

Three measures were decided: the dam raised three zhang in height and thickness, the two sluices sealed, and their opening forbidden by strict order. The gazetteer supplies the contrast — that there had previously been sluices to hold back and release water — and its closing sentence is the verdict of the gazetteer's author, not part of the event. This entry reproduces it and marks it as such.

Consequences

With the two sluices sealed, the water above Guangtong had no outlet. The consequence is recorded in the gazetteer more than a century later: in 1600 the residents Zhang Xiao, Xiong Zicheng and others petitioned the throne, saying that the dam at Guangtong had left the upper waters without release, that more than 80,000 mu of fertile lakeside fields had been destroyed and the quota tax apportioned each year among the villages; they asked with tears for the commutation of grain tax on the Gaochun precedent. In 1622 the prefect of Yingtian Prefecture, Xu Bida, on the report of the magistrate Zhang Ximing, joined the provincial authorities Wang Xiangheng and Yi Yingchang in a joint memorial, and perpetual commutation of Lishui's grain tax was granted; the gazetteer says the whole county was grateful and notes that the matter is recorded in the Complete Book of Commutation.

Uncertainties

First, it is not clear whether the three zhang is the total height and thickness after the work or an addition to an existing dam; the gazetteer's wording allows either reading and no choice is made here.

Second, the gazetteer does not say which prefectures petitioned or by what procedure, nor does it give the position, length or labour of the dam.

Third, the residents' petition of 1600 concerned the commutation of grain tax; the gazetteer links it to the flooding with the single phrase "because of the dam at Guangtong" and gives no calculation of water levels or of the change in field area, so only the wording of the petition is reproduced here.

Fourth, after commutation was granted in 1622, the local officials Yang Gonghan and Zhao Tiyuan petitioned again for it in 1644; before long the dynasty changed and collection resumed as before. The reversals of commutation are recorded in the gazetteer and may be read alongside this entry.

Fifth, on the dating: the Du Shi Fang Yu Ji Yao, juan 20 (as quoted at second hand by Fudan CHGIS), dates the stone sluice to "the middle of the Hongwu era" and the rebuilding as an earthen dam to "the beginning of Yongle", whereas the Kangxi gazetteer dates the sluices and dam to the first year of Yongle and the raising of the dam to 1512; the two chronologies are set side by side. The raising "three zhang" in 1512 is recorded, so far as this library can find, in no corresponding entry of the Wuzong Veritable Records or of the Ming Shi "Rivers and Canals" treatise, and remains peculiar to the county gazetteer.

Sixth, on the seven layers of sources searched: the official websites layer, the published documents and lists layer, the academic layer, the media layer and the maps and fieldwork layer yielded no authoritative material directly on the dam of 1512 (local history writing and news reports that touch on it are second-hand, following the gazetteer or of unstated origin, and are not cited here); the classical-text layer yielded only the two items above, the Du Shi Fang Yu Ji Yao and the Jiangnan Tong Zhi, which cover the identification of Guangtong with Dongba and the general sluice-and-dam history, but not the raising of 1512. The core fact of the dam raised and the two sluices sealed in 1512 therefore still rests on the Kangxi gazetteer alone, and the confidence remains medium rather than being raised by the two later works.