Poyang Lake’s dry season arrives earlier than ever

China’s largest freshwater lake and critical migratory bird habitat has entered its seasonal dry period at the earliest date since records began in 1951.

On 6 August, water levels in Poyang Lake crept below 12 metres, signalling the start of the dry season. The previous earliest date was 22 August in 2006.

The mark was actually reached after a slightly higher than average level of 19.43 metres on 23 June. Since then, however, a heat wave and low rainfall have shrunk the lake rapidly.

Poyang naturally experiences large fluctuations, with five major rivers feeding it and one draining it. It sees higher levels in summer and lower ones through autumn and winter. This has given the lake an important ecological role as a feeding and breeding ground for migratory birds on the East Asian–Australasian Flyway.

But hydrology is not the only influencing factor. The Three Gorges dam, located upstream, has had a major impact on the water flows through to Poyang. Data shows that the water body’s dry seasons have come consistently earlier, lasted longer and been more severe since the dam started holding back water in 2003.

The situation is becoming so severe that some stakeholders are proposing a technological fix. In 2002, provincial People’s Congress members proposed a dam across the lake to maintain winter water levels at 18 metres. The proposal was quickly shot down by central government, academics and environmental groups. But more recently, the idea of a sluice wall has gained new momentum as the local government touted the project not only as a way to manage water levels, but also as a stimulus to the economy. 

The sluice would aim to maintain winter levels at 10-14 metres, supposedly mimicking the natural fluctuations of the lake based on 40 years of hydrological data. Needless to say, the proposal is controversial.

Read more about the plight of Poyang Lake on China Dialogue.