When it rained in drought-stricken Kaohsiung in the second half of May, the southern Taiwan city of 2.7 million people felt relief. 

Water flow in its main artery, the Kaoping River, hit a six-month high on May 22 at 29.6 cubic meters a second, and Mayor Chen Chi-mai proclaimed that if the plum rains continued, the city’s water rationing measures could come to an end.

A day later, however, reality hit. The river’s flow was back down to 21.5 cubic meters a second, reminding residents that the Kaoping River Weir, responsible for about 70 percent of Greater Kaohsiung’s water supply, had remained relatively dry since the beginning of 2023. 

Semiconductor corridor water rationing

To cope with the shortfall, Kaohsiung began to lower water pressure in March to conserve water. The ASE Group, a major IC testing and packaging company based in the area, felt the impact, often turning on the tap only for nothing to come out. 

Its factory is adjacent to the site where the world’s leading contract chipmaker, TSMC, plans to build a semiconductor complex of its own. These facilities lie at the heart of Kaohsiung’s future economic lifeline, dubbed the S (semiconductor) corridor. 

Yet in this emerging industrial cluster that will require substantial amounts of water, ASE has already been managing water shortage risks as though it were manufacturing in a desert. 

The water level of the weir at Kaoping River is so shallow that fish can be seen. (Source: Ming-Tang Huang)

For the past month and a half, Kaohsiung’s supply of water has fallen to only about half of the normal flow, even as it taps into subsurface water supplies.

One kilometer upstream from the Kaoping Weir’s right bank lies a “hyporheic” water well that is hidden about 10 meters below the riverbed. “Hyporheic” water is different from typical groundwater in that it appears where there is porous space beneath or alongside a riverbed and generally flows more rapidly than groundwater.  

This hidden well can provide water in any conditions, and has had its water channeled directly to a water treatment plan over the past three years, becoming a regular water source in the region. 

Other drought-resistant wells 120 meters deep exist near the embankment. Just this year, 43 new drought-fighting wells have been drilled along the Kaoping River, and they pump out more than 100,000 cubic meters of groundwater every day.

Drought relief wells continue to be dug along the Kaoping River. (Source:  Ming-Tang Huang)

A land of water scarcity

“It’s hard for the average person to imagine how much effort so many people have to make to get each drop of water we use in our daily lives,” said Ho Ta-fu (何達夫), the deputy director of the Water Resources Agency’s Southern Region Water Resources Office.     

That can include trying to develop a new water source during a period of drought.
In March, the Water Resources Agency (WRA) was preparing to drill 14 deep-water wells upstream along the Kaoping River in Pingtung County’s Ligang Township, but fierce local resistance forced it to suspend the project.

Statistically, Taiwan gets ample rainfall and should not suffer from droughts. But it was ranked as having the 18th lowest freshwater availability per capita among 146 countries in a World Economic Forum Environmental Sustainability Index in 2005, an oft-cited study that has not been replicated since. 

The contradiction between adequate rainfall and low freshwater availability stems from the uneven distribution of the precipitation and Taiwan’s geographical features such as steep slopes and rapid currents that make catching and storing water a challenge. With most water sources exhausted, those challenges are only getting more difficult to overcome. 

Exacerbating the problem has been consistently rising demand. According to the WRA’s most recent “Plan for Managing Taiwan’s Water Resources,” demand for water in Taiwan in 2036 will still be 7.3 percent higher than it was in 2021, leaving a supply gap of 680,000 cubic meters a day.

Even in times of ample rainfall, cities covering nearly all of Taiwan’s west coast, starting from Hsinchu on down to Taichung, Changhua, Tainan and Kaohsiung, will face water shortages, the WRA projected, and if there is little rain, those cities’ water supplies will come under intense pressure.

Climate change making things worse

In the spring of 2021, Taiwan experienced what meteorologists called the “drought of the century.” Just two years later, drought-stricken parts of southern Taiwan are again facing water shortages, only this time major reservoirs in the region are even worse off.

Weather experts believe Taiwan will experience droughts even more frequently and for longer in the future.

“In the past, water shortages would appear for a brief period, but then rain would come and eliminate the threat. In the future, however, that pressure will only grow stronger,” said Hsu Huang-hsiung (許晃雄), a research fellow with Academia Sinica’s Research Center for Environmental Changes.  

He contended that when devising contingency plans for the management of its water resources, Taiwan should start simulating extreme weather scenarios that have never happened before in order to avoid being caught unprepared.

Chen Hongwei, a rice farmer in Tainan, can only plant sunflowers as green manure to maintain his land because of the fallow. (Source: Ming-Tang Huang)

Reservoir backup planning

In the “drought of the century” two years ago, the government played pretty much every card it had in its hand, successively exploiting hyporheic water sources, drought-resistant wells, water from ponds, and recycled water. It even built a temporary seawater desalination plant along the Hsinchu coast just to provide about 3,000 cubic meters of water a day.

The WRA also used its pipe network to move water from one region to another. In northern Taiwan, for example, the Feitsui Reservoir, which normally supplies Taipei’s water, was used to help out neighboring New Taipei so that New Taipei’s main water source, the Shihmen Reservoir, could divert some of its water to Hsinchu and keep the world-famous Hsinchu Science Park running. 

Similarly in the south, water from the Kaoping Weir was piped to the Nanhua Reservoir to ensure that Tainan and its science park would have sufficient supplies.

Hyporheic water, currently the largest and among the least expensive drought-resistant water sources, now accounts for about one million cubic meters of water a day. The administrative arm of the government, the Executive Yuan, is investing in a second- phase project that will increase this supply by 250,000 cubic meters a day.

Large amount of underground stream in the Kaoping River watershed. (Source: Ming-Tang Huang)

To give itself more flexibility, the WRA has also installed water pipes connecting the Tsengwen and Nanhua reservoirs in the south and the Shihmen and Second Baoshan reservoirs in the north, expanding two-way water conveyance capabilities.

Even recycled water and desalination facilities, which have strategic significance as sources of reserves and diversification of the water supply, are being built up around Taiwan.

They are all part of a network desperate to squeeze out every drop of water available. Pointing to a map of Taiwan, WRA Director-General Lai Chien-hsin (賴建信) compared the water supply corridor in western Taiwan as a “string of pearls” that needs to be cherished and used appropriately.

During spring times, Tainan and Kaohsiung are often short of water, the Water Resources Department is stepping up the construction of the Zengwen and Nanhua reservoir interconnection pipe to transfer water.(Source: Ming-Tang Huang)

The WRA has estimated that reducing leaks in the water piping network and reservoir dredging could boost water reserves by another billion cubic meters, which would help extend southern Taiwan’s period of adequate water reserves that usually lasts until May for another three months to August, when typhoon season normally arrives.

But the extremes to which the WRA has already gone to boost reserves indicate there are few water sources left for Taiwan to exploit. 

“Taiwan cannot withstand two years of drought in a row,” asserted Tung Ching-pin (童慶斌), a professor in National Taiwan University’s Department of Bioenvironmental Systems Engineering. 

Droughts becoming the new normal

Tung said that hyporheic water and groundwater sources are similar in that there are limits to how much they can supply without affecting the environment. At the same time, the desalination process is highly energy intensive, tantamount to trading energy for water. Not only is it extremely expensive, Tung said, but counterproductive to the goal of net-zero emissions and should not be used rashly.

Finally, Tung said, if Taiwan were to face drought conditions that led to major shortages, re-channeling potable water from one reservoir to another would be ineffective. 

Without many good alternatives, You Jiing-yun (游景雲), a professor in NTU’s Department of Civil Engineering, worried that “if droughts become a new normal, Taiwan will be extremely vulnerable.” 

Former WRA Director-General Chen Shen-hsien (陳伸賢) agreed, and argued that “Taiwan should abandon its extraction-oriented thinking, and consider a sustainable model of ‘setting demand based on supply,’” a concept that simply means living within one’s means.  

Typically in Taiwan, companies investing in factories submit their requests for water, and the government tries to find ways to meet that demand. Now, however, at a time when all sources have been exploited, Taiwan should set its water usage and investment strategies based on the water it can supply.  

In areas where farmers compete with residential and industrial users for water from such reservoirs as the Shihmen, Mingde, or Wushantou reservoirs, for example, agricultural agencies could encourage farmers to plant more drought-resistant crops or diversify their water sources. They could help them set up equipment to acquire water from rivers or build eco-friendly water storage ponds. 

Industrial agencies have already entered the water conservation age, using pricing to limit usage.

Beginning this year, the Ministry of Economic Affairs (MOEA) has been charging big water users a surcharge of NT$3 per cubic meter for all water used beyond 9,000 cubic meters a month, a policy the WRA’s Lai said has paid dividends. 

Reclaimed water plant at TSMC's Nanke site to increase multiple sources of water intake. (Source: Chien-Ying Chiu)

In the first five months of 2023, Lai said, water usage in the Southern Taiwan Science Park was down 18.86 percent from the same period a year earlier, and usage in the city of Taiwan was down 8.8 percent. 

Missing: A national water management strategy

Taiwanese are relatively heavy water users, and the country’s low water prices give them little incentive to curb their habits. Increasing water prices is a highly sensitive political topic, however, and one that the MOEA is not in a position to decide.

Yu Pao-shan, a professor emeritus at National Cheng Kung University in the Hydraulics and Ocean Engineering Department, suggested that the central government take the lead in guiding and coordinating water, environmental, agricultural, industrial, and land agencies along with local governments in strengthening management of water demand.

Yu’s suggestion echoed the United Nations’ emphasis on a “cross-sectoral policy approach” as part of its concept of “integrated water resource management” and a campaign by South Korea to use water more efficiently.  

In 2018, South Korea revised its laws to overhaul its water resources management framework, going from a system in which every agency acted on its own to one focused on integrated planning and management. The Ministry of Environment was made responsible for both the water supply and water quality, and a National Water Management Committee under the president was launched in August 2019.

The WRA’s Lai said his agency had done everything it can to develop new water sources, juggle existing sources to get water to where it was most needed, and build reserves, but those moves were designed to meet short-term supply goals. 

In the longer term, he warned, Taiwan will have to change its water habits if it hopes to have any chance of meeting its sustainability goals and maintaining a stable supply of water for the many competing interests for the precious resource. 

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Have you read?

• How Taiwan’s expanding semiconductor industry deals with water shortages 
• Taiwan's water crisis

Translated by Luke Sabatier
Edited by TC Lin
Uploaded by Ian Huang