TAIPEI (Taiwan News) — TSMC’s growing semiconductor operations in Japan’s Kumamoto Prefecture are boosting the local economy but raising concerns over the sustainability of groundwater use, The Mainichi reported Sunday.
TSMC’s factory in Kikuyo, a town near Kumamoto City, began mass production in late 2024 as part of Japan’s efforts to strengthen its semiconductor supply chain. The Japanese government has provided more than NT$200 billion (about US$6.17 billion) in subsidies to support the company’s investment, with a second fab now under construction.
Kumamoto is known for its abundant groundwater. About 80% of household water in the prefecture comes from groundwater, which is also essential for making chips.
TSMC’s first factory uses up to 30,000 metric tons of water per day, with about three-quarters supplied through recycling systems, per The Japan Times. The remaining amount comes from groundwater, with the plant drawing about 2.5 million tonnes last year. To offset the impact, local farmers have expanded winter rice paddy flooding projects that help recharge groundwater.
The projects gained momentum after concerns emerged in 2023 that increased industrial water use could threaten Kumamoto’s groundwater supply. Under revised prefectural guidelines, companies are now required to restore an amount of groundwater equivalent to their consumption through measures such as paddy flooding.
However, maintaining the balance has become difficult as many farmers involved in the projects are aging, per The Mainichi. The 13 farmers participating in the Seta district have an average age of 74, and some say the physical demands of winter work raise concerns about whether the effort can continue.
TSMC said the groundwater and other water resources restored through farmer-led projects in fiscal 2025 exceeded three times the amount pumped by the company. However, with the second factory expected to produce more advanced chips for applications such as AI data centers, water demand is projected to more than triple from current levels.
