The Hidden Drought in China’s Subtropics
GUANGDONG, South China — In early December, hydraulic engineering professor Huang Guoru read a surprising notice from his school. The South China University of Technology’s logistics office told staff and students to prepare for unannounced water supply cuts.
“People from other regions are never going to believe this,” he wrote in a post on social networking app WeChat. “We are in the middle of a drought in a place in Southern China with annual precipitation of 1,600 to 1,800 millimeters” — about three times more than the country’s capital, Beijing, for example.
An expert in hydrology, Huang knows it’s long been a challenge for the populous and productive Guangdong province to meet its water needs, but the notice marked the first time in the 16 years he has taught at the Guangzhou-based university that he was personally affected by it.
A lack of water is a more familiar scourge in China’s northern half. There, deserts are growing and underground aquifers are shrinking. Despite country-spanning channels dug to quench the north’s thirst, water scarcity is one of the most pressing challenges for the area’s long-term development outlook. All in all, the amount of water available per person in China is just one-fourth of the world average.
In contrast, China’s south is crisscrossed by rivers and usually has more to fear from floods. Winters are dry, and sometimes lead to droughts. They are getting more severe as weather patterns shift and companies and households consume more water. Subtropical parts of China are now too having to tighten their taps. Will Guangdong, one of China’s economic growth engines, have to throttle back?
The Pearl River
Guangdong is defined by the Pearl River, with the province’s biggest cities clustered around its delta. The river mainly consists of three big tributaries: the West, North, and East rivers, which stretch to and beyond the province’s borders. The latter river, an important source of surface water, has seen low water levels due to a shortage of rainfall since the fall of 2020, according to local media.
The provincial government calls it the most severe drought in over 60 years, and has urged residents to save water while warning of shortages that will last into February. Since November, cities situated along the lower reaches of the river, including provincial capital Guangzhou and Dongguan, have also been dealing with a severe salt tide, a situation when the river’s flow is low enough to allow seawater to push inland and threaten drinking water sources.
Coursing down from the mountains in neighboring Jiangxi province, the East River supplies water to close to 40 million people in the Pearl River Delta, including the people of Hong Kong. Both Shenzhen and Dongguan, for example, rely on the East River for over 90% of water supplies. But as the local economy and population have grown and living standards have risen, it has been under constant pressure to ensure water security, according to Huang.
To make matters worse, “the inflow of water (to the East River) is the smallest since 1991,” Huang told Sixth Tone. Last year, the three major reservoirs in the East River basin were only able to release 1.26 billion cubic meters of water, a three-decade low. “It is seriously mismatched,” he said.
Whereas water scarcity in China’s drier north is a chronic issue, seasonal weather swings can suddenly present China’s south and east with “acute” water stress, according to Luo Tianyi, director of Aqueduct, a water analysis data service at the non-profit World Resources Institute.
A year ago, historically low rainfall over a period of months resulted in a drought across nearly the entirety of eastern China’s Zhejiang province, drying up reservoirs and prompting local governments to cut supplies to water-intensive businesses such as saunas and swimming pools.
“Indeed, from a long-term perspective, water resources in the south are relatively abundant,” Luo told Sixth Tone. “But the more abundance there is in such places, the easier it is to catch everyone by surprise” when droughts do hit.
Pollution and climate change
Global warming is causing more such surprises. Li Kuo, a researcher at the Chinese Academy of Agricultural Sciences, told Sixth Tone that successive months of drought in the East River basin should be seen as an extreme weather pattern influenced by climate change.
The wider Pearl River Delta region is an example of what happens when extreme economic growth comes up against limits imposed by climate change. Its cities have planned their futures assuming water supplies based on weather patterns that no longer hold.
Manufacturing hub Dongguan, for example, gets most of its water from reservoirs and streams fed by precipitation. But rising temperatures have left the watersheds of the rivers Dongguan relies on drier and less dependable, according to Lin Kairong, professor of water resources at Guangzhou’s Sun Yat-Sen University.
Its countless factories have left much of Dongguan’s water sources too polluted to use for tap water. As a result, the city’s 10 million residents have a per person water availability of just 217 cubic meters a year, according to government data — much less than 500 cubic meters, the amount considered by the United Nations to indicate “absolute scarcity.” Amid the drought, the city has rationed water for industrial users.
Provincial officials are looking for new water to tap by investing in infrastructure such as dams, water treatment plants, and water transfer projects. The biggest project on the books, costing an estimated 35.4 billion yuan ($5.56 billion), is a diversion of the West River to supply some of the thirstiest cities. The project is moving ahead despite objections from environmental groups, and, once complete in 2024, it is expected to alleviate water scarcity in Guangzhou, Dongguan, and Shenzhen, as well as provide backup supplies to Hong Kong.
Huang told Sixth Tone that he had previously considered it unnecessary to spend so much money on the water transfer project. But droughts in recent years have changed his mind. “It would be too risky if you didn’t do it,” he said. Considering the “extraordinary” imbalance between water resources and population growth, “it would be very difficult to solve without some large-scale water transfer projects,” he said.
In the end, Huang did not have his water supply cut, a result of an efficient government response, he reckons. Also, in mid-December, heavy rainfall brought by Typhoon Rai alleviated Guangdong’s drought. This too was an effect of climate change. “It was the latest typhoon in history,” said Lin, the water resources professor. Typhoon season commonly ends in October or November.
But droughts will reappear — and this year’s isn’t entirely gone yet. In some neighborhoods, the salt tide is still giving tap water a saline flavor. In a Jan. 28 notice addressing residents of Guangzhou’s Huangpu District, the local water utility company warned that nighttime water pressure would be low, and recommended to stock up on water in case of temporary water cuts during the Lunar New Year holiday, which starts on Jan. 31.
“Cherish water, love water, save water; it starts with me, it starts now,” it reads.
Additional reporting: Zhu Ruiying; contributions: Xu Jialu; editor: Kevin Schoenmakers.
(Header image: A view of the drought-affectedWanlü Lake, Heyuan, Guangdong province, May 23, 2021. Southern Visual/People Visual)