From the 7th century, when the Grand Canal was conceived as a unified means of communication for China for the first time, to the mid-19th century, the Grand Canal underwent continuous development and improvements, and numerous projects were undertaken with regard to the Grand Canal using nearly all planning, design and construction techniques available during the period of agricultural civilisation.

The Chang’an Water Gate is an important hydraulic complex connecting the Jiangnan Canal and the Shangtang River Net. In 1068, the Chang’an Weir was reconstructed into the Three Chang’an Water Gates, making a multiple ship lock and a boat-towing dam coexist. It is the earliest multiple ship lock in world water transport history. The Daicun Dam is an important component of the Nanwang hydraulic complex, allowing the Grand Canal to cross the “water ridge” in Shandong, and is one of the most technical sections of the Grand Canal.