Engraved in the rock are 163 inscriptions and pictures, which include 114 hydrologic annotations, which give detailed records of water levels in the river over 1200 years, since the first year of the Tang dynasty Guangde era, 763; the assembled inscriptions and fish carvings, taken together, formed the longest such sequence in the world. One fish carving originally carved in the Tang dynasty was recarved at a moment of lowest water in 1685: modern measurements recorded the elevation of their eyes, 137.91 meters, almost the same as that of the zero point of the modern water level gauge.

The fish carvings and hydrological inscriptions were virtually unknown in the West until the 1970s, when Chinese experts presented photos of these two fish and hydrological data of Fuling for the past 1,200 years at an international hydrological symposium held in the UK.

The best-known of the fish carvings was a 2.8-meter carp, carved from a section of freestone. Hundreds of poetical homages to the place were inscribed in rock faces, which have disappeared beneath the rising waters as the dam has been completed. In 2003, Xinhua News Agency, the People's Republic's official press agency, headlined the on-line story, June 10, "Accident-maker reef no longer threatens Yangtze navigation".

The inscriptions on the "White Crane Ridge" will be on display in an underwater museum, due to finish construction in 2007. Main body of Baiheliang underwater museum completed

See also

• Nilometer

References

• China.org: Baiheliang: Ancient Hydrologic Station
• "Accident-maker reef no longer threatens Yangtze navigation"