Plans for a harbor tunnel under the South China Sea have been approved, paving the way for the construction of the Hong Kong-Zhuhai-Macao Bridge.

The 6.7-km tunnel will cost 21.1 billion yuan (US$3 billion) and will run 40-m below sea level so it does not interfere with shipping traffic.

Its approval means construction can begin on a 29.6km bridge that will run above the tunnel and connect three major cities in the Pearl River Delta region.

A statement released on Thursday said building of the bridge would begin by the end of the year. The six-lane bridge is estimated to cost up to 72.6 billion yuan and will have a speed limit of 100-kmph per hour.

Two artificial islands will connect the tunnel and bridge at either side.

Zhang Xigang, general manager of the China Communications Construction Highway Consultants, responsible for the preliminary design of the bridge, said: "We give the utmost importance to sea environmental protection, especially protection of the white Chinese dolphins."

Hong Kong highway authorities said an environmental impact assessment would be completed in the coming months.

(China Daily April 9, 2009)