Mechanisms to cope with GBA drought successful

Despite rare drought conditions in the Pearl River Basin that lasted until early March, the Ministry of Water Resources managed to ensure the supply of water to the Guangdong-Hong Kong-Macao Greater Bay Area thanks to intensified efforts to divert water and build emergency water stocks.

Due to a continuous period of low rainfall, the basin suffered from severe drought in 2021 and the first two months this year, said Liu Zhiyu, deputy head of the ministry's information center, at a news conference on Monday.

In the eastern part of the basin, the areas along the Dongjiang and Hanjiang rivers saw 20 to 40 percent less precipitation than normal in 2020 and 2021, he noted, adding that annual precipitation last year in both areas hit its lowest level since 1961.

During the drought, inflows to both two watercourses decreased by 70 percent. Reserves at key reservoirs fell to less than 20 percent of total capacity, he continued.

Frequent salt tides worsened the situation and as a result, water plants in Zhuhai and Zhongshan in Guangdong province sometimes failed to harvest any fresh water from the two rivers for several days at a time.

With limited local water resources, the Guangdong-Hong Kong-Macao Greater Bay Area depends on water from Dongjiang and Xijiang rivers, he said. Macao, Zhuhai, Dongguan and Guangzhou in particular rely heavily on the estuaries for water.

"When the Pear River Basin was simultaneously stricken by drought and salt tides, the estuaries filled with salt water, leading to a sharp decrease in the ability to harvest fresh water there," Liu said.

To cope, the ministry's Pearl River Water Resources Commission and the Guangdong Provincial Department of Water Resources rolled out real-time forecasting for salt concentrations in estuary waters, he said. The forecasts helped water plants take advantage of every opportunity to harvest fresh water.

The two government bodies also boosted water diversion to the area via joint operation of the reservoirs in the Pearl River Basin, he added.