In April, Poyang lake covers an area of nearly 4,000 square kilometres, according to state television CCTV. It now covers less than 600 square kilometres, according to the report.
Poyang Lake, located in one of the Yangtze river's flood plains and described as China's "kidney" because of the role it plays in regulating water supplies, is now 67% smaller than the average over the last 10 years, CCTV reported.
China remains on a heat "red alert" for the 12th day on Tuesday, temperatures are expected to fall in parts of central China by Wednesday, and in Sichuan and Chongqing from Aug. 29, the National Meteorological Center said on its official Weibo channel.
State forecasters said China's heatwave, which has lasted more than two months, was about to hit a "turning point," with a cold front looming from the west and a typhoon approaching in the southeast.