On May 15, 2006, Chinese news media reported that engineers were pouring the last of the concrete to finish the construction of the massive Three Gorges Dam on the Yangtze River in central China. The dam is intended to provide flood control and hydroelectric power. When all the generators are operational (projected for 2009), Three Gorges will become the largest hydroelectric project in the world.
This pair of images shows the dam in partial completion in July 2000 and again in May 2006. The Yangtze River flows from upper left toward upper right in the images. In 2000, construction along each riverbank had occurred, but sediment-filled water still flowed freely through a narrow channel near the river’s south bank (bottom left). A smaller passage closer to the north bank of the river, where the water appears calmer, is likely a system of temporary locks that allowed for boat passage. A second dam bypass appears to be under construction about 1 kilometer to the north.
By May 15, 2006, the dam spanned the entire river, and a large reservoir had filled behind it, to the northwest. The new reservoir is more than 3 kilometers (more than 2 miles) across just upstream of the dam. White spray shoots through gates in the center portion of the dam. The former locks are much less prominent, and the new ones to the north appear as a linear arrangement of thin, blue rectangles.
NASA image created by Jesse Allen, Earth Observatory, using ASTER data made available by NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.