This aerial photo taken on Nov. 16, 2023 shows a view of Panxi River in Yubei District of southwest China's Chongqing Municipality. (Xinhua/Wang Quanchao)

China's water quality levels saw stable improvement in the first three quarters of this year, data from the Ministry of Ecology and Environment shows.

During the period, the proportion of surface water at or above tier three in the country's five-tier water quality system rose 0.8 percentage points year on year to 87.1 percent, according to the ministry.

The proportion of surface water at tier five, the lowest level, stood at 0.7 percent, 0.2 percentage points lower than the same period last year.

The water quality of China's major rivers, lakes and reservoirs generally improved in the January-September period. The proportion of water at or above tier three in the Yangtze River, the Yellow River and other major river basins increased 0.7 percentage points year on year to 89.2 percent.

Of the 209 key lakes and reservoirs monitored by the government, 74.6 percent saw water quality levels at or above tier three, up 0.8 percentage points from one year earlier.