Between June 2003 and November 2008, the water level behind the Three Gorges Dam was raised three times from 135m to 156m and then 172.3m. These occasions go unmarked, with the passage of time and rising tide marked only by the disappearance of these sign boards indicating the height of the water-level. Here, a cargo ship sails past a 175m signboard along the Wu Gorge [Nov 08 2008].
