On February 22, the Yellow River crossing tunnel, a key project of the South-to-North Water Diversion Middle Route Project, began a water-filling test. The test will examine the structural safety performance, lining stress, seepage control, drainage conditions and concrete quality of the tunnel under water-filled conditions.

The Middle Route Yellow River crossing project is located at Gubozui, about 30 kilometers west of Zhengzhou City in Henan Province. Construction began on September 27, 2005. It is a control structure of the South-to-North Water Diversion Project with relatively large investment, the highest construction difficulty and the largest scale of crossing. The main task of the Yellow River crossing project is to safely and effectively convey water diverted by the Middle Route from the south bank of the Yellow River to the north bank.

  The water-filling test uses water from the Yellow River and is carried out by staged filling and staged drainage. The Middle Route Project has a long route, many structures and complex topographic and geological conditions along the line. Before trial water conveyance along the entire line, safety inspections of the control structures and other related facilities of the main canal will play a key role in promptly identifying and addressing possible quality problems in the canal and structures and in screening for hidden safety hazards. It will also create conditions for the smooth trial water conveyance of the entire first-phase Middle Route Project. According to plan, the Middle Route Project will conduct a full-line water-filling test in early June.