Yuan Shizu reused outstanding scientistsGuo Shoujing, let him be in charge of water conservancy work across the country, dredging rivers and canals, to facilitate transportation and material exchanges between north and south. On January 26, 1291 AD (December 25, the 27th year of the Yuan Dynasty), according to Guo Shoujing's suggestion, Yuan Shizu diverted springs from the northwest of Dadu and re-built them on the basis of the original grain transportation river in the Jin Dynasty. It runs east to Tongzhou and enters the Baihe River. It has a total length of 164 miles, with 11 Jianba lakes, totaling 20. Named it "Tonghui River". In this way, supplies from Jiangnan can be transported directly to Dadu via Hangzhou.