China’s Largest Freshwater Lake Poyang Lake Sees Sharp Water-Level Drop

September 30, 2026

Poyang Lake, China’s largest freshwater lake, has experienced a rapid decline in water levels in recent weeks, with the retreat occurring significantly earlier and faster than the historical seasonal pattern. Data from Jiangxi’s hydrological monitoring authorities show that the lake’s representative Xingzi hydrological station fell below the 12-meter low-water threshold on September 20. By 8 a.m. on September 29, the water level had dropped to 10.26 meters.

The decline accelerated sharply in mid-September. According to information released by the Jiangxi Provincial Department of Water Resources, the Xingzi station recorded a water level of 15.55 meters on September 8. By 8 a.m. on September 22, the level had fallen to 11.29 meters, a decline of 4.26 meters in just 14 days. Between September 16 and September 22, the lake level dropped by 2.47 meters, with daily declines exceeding 0.4 meters for several consecutive days. The provincial water authorities described the speed of the decline and the frequency of records being broken as unusual.

Low-Water Season Arrives 42 Days Early

Poyang Lake is a highly seasonal, river-connected lake whose water levels fluctuate significantly depending on rainfall, inflows from rivers across the basin and conditions in the Yangtze River.

The lake normally enters its low-water season later in the year. This year, however, the Xingzi station dropped below the 12-meter low-water threshold on September 20 — about 42 days earlier than the long-term average date.

The rapid decline has also caused the lake’s open-water area to shrink considerably. By September 22, the area of water directly connected to the river system had fallen to about 41% of its annual peak. Large areas of mudflats and grasslands became exposed, attracting egrets and other birds seeking food in the shallow areas.

What Is Behind the Rapid Decline?

Hydrological authorities have attributed the recent decline primarily to weather conditions and reduced inflows from upstream areas.

Poyang Lake has a distinctive seasonal hydrological pattern. During periods of falling water levels, reduced rainfall and lower inflows from major rivers can accelerate the decline, particularly when water continues to flow out of the lake toward the Yangtze.

On September 21, inflows from the lake’s five major tributaries were reported at about 2,150 cubic meters per second, while the outflow was approximately 3,920 cubic meters per second. The difference between inflow and outflow provided an important hydrological background for the rapid fall in water levels.

Implications for Water Resources and Ecology

Changes in Poyang Lake’s water level affect far more than the appearance of the landscape. They can influence water supplies for agriculture and local communities, as well as the lake’s wetland ecosystem.

As water levels fall, the lake’s connected water area and storage volume decline. Data released earlier in September showed that the connected water area had fallen to about 1,330 square kilometers by September 21, 443 square kilometers smaller than a year earlier. The lake’s water volume was approximately 2.7 billion cubic meters, 1.22 billion cubic meters below the same period last year.

Lower water levels can also alter habitats for aquatic plants, fish and migratory birds. With the autumn and winter migratory-bird season approaching, changes in water levels and wetland conditions are expected to remain an important focus for ecological monitoring.

Authorities Expect Water Levels to Continue Falling

The current low-water episode has not yet ended.

Based on current rainfall and hydrological conditions, Jiangxi’s water authorities expect Poyang Lake’s water level to continue declining in the near term. Authorities have urged areas around the lake to closely monitor water conditions and strengthen water-use management, drought preparedness and water conservation.

The sharp decline should not, however, be interpreted as the lake drying up completely. Poyang Lake is a large river-connected lake whose water level naturally changes in response to rainfall, tributary inflows and the level of the Yangtze River. Historical fluctuations have included both rapid declines and subsequent rebounds.

The current event is more accurately described as an unusually rapid retreat of the lake’s water level and an early onset of the low-water season.

Hydrological authorities are continuing to monitor the lake closely. Future rainfall, tributary inflows and Yangtze River conditions will be key factors in determining how Poyang Lake’s water level develops through the coming weeks.