Wuzhong shuili shu 吳中水利書 "Book on water conservancy of the region of Wu" is a description of water conservancy works in the region of Suzhou 蘇州, Changzhou 常州 and Huzhou 湖州 (called Wuzhong or Sanwu 三吳 "The Three Wu"), Jiangsu, compiled by the Northern Song-period 北宋 (960-1126) scholar Shan E 單鍔 (1031-1110), courtesy name Jiyin 季隱, from Yixing 宜興. The book was finished in 1088 and presented to the throne by the famous writer Su Shi 蘇軾 (1037-1101). It is therefore included in Su's collected writings, Dongpo ji 東坡集.
A map of Shan E's book titled Sanzhou jianghu xihai tu 三州江湖溪海圖 is not included in Su Shi's official version and is therefore lost.
The region around Lake Taihu 太湖 was an important economical centre of the Song empire, and it therefore belonged all the more to the duties of the local government to care for irrigation and drainage of this water-rich area. The growth of the urban centres in the Lower Yangtze region required a higher productivity of China's granary. In the early 11th century a thorough repair of dams and dykes and the clearance of the canals were highly necessary. In 1089 Su Shi was appointed prefect (zhifu 知府) of Hangzhou 杭州, which was a good opportunity for Shan E to stress that the government had the duty to undergo large-scale hydraulic works.
In his book Shan E explained what works had to be undertaken and suggested concrete measures at specified points, like the Wuyan Dam 伍堰 and River Wujiang 吳江. The River Wujiang had to be freed of silk and to be furnished with fastened banks, so that the water would run faster. The Wuyan Dam was to be rebuilt in order to control the waters of the Xuxi Canal 胥溪運河. Furthermore, the Jiazhu Canal 夾苧干瀆 was to be amended so that the waters were flowing less quickly and could be forked out towards the Yangtze River. After restructuring these main arteries their waters were to be branched off to provide water for the adjacent fields. In times of flood, water was to be offset in large basins and so could be used to plenish canals and rivers.
The Wuzhong shuili zhi was the first treatise suggesting concrete measures to enhance the use of water in the lower Yangtze area and had a large impact on later writings. The measures Shan E described in his book were applied by many later prefects of the Taihu region, like Xia Yuanji 夏元吉 (1366-1430) or Zhou Chen 周忱 (1380-1453) during the early Ming period 明 (1368-1644).
Yet there were also persons criticizing the construction works suggested by Shan E. Gui Youguang 歸有光 (1506-1571), for instance, saw not advantage in the reconstruction of the Wuyan Dam. Wang Tongzu 王同祖 (1497-1551) even argued that a reinforcement of the banks of River Wujiang would lead to more inundation in the districts of Wujiang 吳江, Kunshan 崑山 and Changshu 常熟.