How do water-deficient coastal cities ensure sufficient water supply?

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China.org.cn

Aug 13, 2026, 09:00 ET

BEIJING, Aug. 13, 2026 /PRNewswire/ -- A news report from China.org.cn on seawater desalination technology:

It sounds paradoxical for a waterfront city to suffer from water shortage. However, this is the situation in China's many coastal cities where seawater is abundant but freshwater is scarce.

How do water-deficient coastal cities ensure sufficient water supply?

In Qingdao, Shandong province, the per capita water resources have remained at a mere 186 cubic meters for many years, less than half of the 500-cubic-meter international warning line. In Tianjin, the number is 100 cubic meters and, in some years, even lower than in Saudi Arabia. This pressing water deficiency led many people to wonder if there is a way to turn the endless supply of seawater into freshwater for sustainable use.

The solution lies in the transformation of seawater desalination technology.

A giant chemical plant uses more water each year than a city of 1 million residents. If such large consumers use only underground water, the domestic water use will be squeezed tightly. Meanwhile, seawater intrusion caused by lowered underground water level will lead to catastrophic damage to the entire underground water system. Desalination technology can turn seawater into freshwater to provide sufficient supplies for both industrial production and daily life, therefore ensuring water security in coastal areas.

This is not simply an idea. It is what is happening in real life.

At Huni Island in Zhoushan city, Zhejiang province, rainwater used to be the only water resource, and the domestic water supply was limited and available only at certain times. Industrial production was often disrupted due to water outages. The situation changed when a seawater desalination plant was built in October 2025. The plant produces 10,000 tons of clear freshwater daily for local households to use 24 hours a day, not confined to contingency use.

At Nangang Industrial Zone in Tianjin, a thermal power plant suffered from short supply of freshwater for a long time because its production requires large amounts of high-quality freshwater. Now, through seawater desalination technology, it has secured a stable supply of industrial water, and thanks to improved water quality, water usage and pollutant discharges have reduced significantly, saving 10 million yuan each year. Desalinated seawater has become the primary water source at the industrial zone.

In Qingdao, the concentrated brine left over from seawater desalination is now being used as a raw material to help bring seawater-based potassium extraction from the lab to the production line.

Today, desalination is no longer just a technology or an emergency stopgap. It has become a strategic cornerstone vital to a country's prosperity and people's well-being. This is especially true in the Middle East, where it is even a matter of national survival and security. This region possesses only 2% of the world's renewable freshwater, with 83% of its territory suffering from severe water scarcity. To survive, countries have no choice but to turn to seawater desalination. Kuwait relies on it for as much as 90% of its freshwater needs, while for Qatar and Bahrain, that figure reaches 100%.

China's desalination industry has undergone a transformation from technological dependence to exporting solutions. There was a time when the reverse osmosis membranes, the core component of China's desalination system, depended largely on imports. However, after years of dedicated technological breakthroughs, the three core components — reverse osmosis membranes, high-pressure pumps and energy recovery devices — can now all be produced domestically. China's technology has not only met complex domestic water quality demands but also found applications abroad. Through Belt and Road cooperation, Chinese companies have undertaken large-scale desalination projects in countries such as Egypt and Algeria, offering Chinese solutions to the global water crisis.

By the end of 2025, China had completed 167 seawater desalination projects, with a total daily freshwater output capacity of 3 million tons, enough to meet the daily domestic water needs of 15 million people.

From Zhoushan's island to Tianjin's industrial zone, and from a technology importer to a solution exporter, China is turning the vast blue ocean into a giant reservoir for humanity. This is not only an answer to China's own water challenges, but also a fulfillment of its commitment to building a community with a shared future for humanity.