Crossing the sea to upgrade the stability of water supply in Qijin

Qijin Second Transmission Mains Design and Construction Management Services

Qijin is a long slender island located in western Kaohsiung City. Currently, for its running water, Qijin relies on one three-decade-old transmission main which is attached to the cross-harbor tunnel and has had a gradual increase in leakage incidents over the years. However, as this is the only active transmission main and there’s no storage tank on the island, repair services are limited to nighttime (or off-peak time) work. With these challenges in mind, the Taiwan Water Corporation (TWC) launched a new transmission main build project intended to reduce the risk of water scarcity in normal operation and when repairs are needed. Our job? Conduct the design work and construction supervision.

The method of installation needed to minimize the impact to the harbor operation as much as possible. Therefore, the team chose trenchless construction as the main technique. The method includes one kilometre of curved horizontal directional drilling (HDD), shield tunneling, and pipe jacking in a limited working space.  

Besides the preliminary engineering design, compilation of bidding documents, and procurement, our team provided supervision of the construction period and completion acceptance. We also provided geographic investigation of the buried routes, path design, material and construction specification, design drawing, cost budgeting, coordination with stakeholders, and permit application.

After project completion, the TWC and the Qijin community benefitted from the increased water dispatch backup capability. The water supply impact to local citizens—in the case of repair services—was reduced, ensuring the stability of running water and industrial water needs.