China's Yangtze River is suffering its worst drought for more than 50 years (Nature doi:10.1038/news.2011.315; 2011). Although people blame the Three Gorges Dam for making matters worse, other factors have also contributed.

In response to April and May's severe water shortage, central government ordered the release of 50 billion cubic metres of water from reservoirs in the Yangtze basin, most of which came from the Three Gorges Reservoir, with some from other reservoirs used for power generation. The result is a cumulative toll on the river's large-scale hydrological balance.

Extensive land reclamation in the middle and lower reaches of the river has exacerbated the drought by removing or shrinking many natural lakes across the river basin. Worse, more than 80% of the remaining lakes are no longer connected with the river, seriously limiting their capacity for buffering the water supply.

Excessive pumping of groundwater is a significant contributor to the current drought (see http://go.nature.com/b6Srkg; in Chinese), as are channel incisions caused by loss of sediment and sand mining.

The drought's severity threatens China's south–north water-diversion project, a huge trans-basin scheme to ease the water shortage in northern China.