TAIPEI (Taiwan News) — Southern Taiwan is sliding deeper into drought as storage at the nation’s largest reservoir nears historic lows, News and Market reported Monday.
Storage at Zengwen Reservoir in Chiayi County has fallen to 9.6%, only three percentage points above the record low reached during Taiwan’s 2021 drought. Downstream Wushantou Reservoir has also seen water levels plunge, exposing cracked reservoir beds and increasing pressure on the Chianan Irrigation Waterway.
According to the Water Resources Agency, Tsengwen Reservoir holds 43.4 million metric tons (about 9.6%), Wushantou Reservoir 11.58 million metric tons (about 14.6%), and Nanhua Reservoir 18.7 million metric tons (about 22.8%), per NewTalk. Combined, the three reservoirs contain only 73.68 metric million tons.
The worsening shortage follows below-average spring rainfall and a delayed plum rain season that has delivered more precipitation to northern Taiwan than to the south. Southern Taiwan relies heavily on spring rains, plum rains, and typhoons to replenish reservoirs, leaving the region vulnerable when those sources fail.
The WRA said irrigation for Chianan’s second rice crop season will be postponed, per News and Market. The first irrigation phase had been scheduled to begin on Saturday, but officials said reservoir levels are too low to maintain the original timetable.
Irrigation officials said they remain committed to avoiding a suspension of irrigation. A revised schedule is expected to be discussed around June 10, with advance notice to farmers and seedling nurseries once a final decision is made.
WRA Deputy Director-General Wang I-feng (王藝峰) said the completion of the first rice crop harvest has temporarily reduced agricultural demand, allowing authorities to prioritize domestic and industrial water supplies. Officials estimated that southern Taiwan still has about one month of water reserves even if significant rainfall does not arrive.
Recent infrastructure projects have improved flexibility in water management. The Tsengwen-Nanhua pipeline now allows water transfers directly to Nanhua Reservoir, while supplies from the Kaoping River and other regional systems are helping stabilize demand.
Officials said the critical factor for farmers is whether irrigation can begin before the point at which rice can no longer complete its growing cycle. Forecasts for plum rains and localized thunderstorms offer some hope, though rainfall totals remain uncertain.
The agency said balancing residential, industrial, and agricultural needs remains its priority. Authorities will continue monitoring weather conditions and adjust water allocations as necessary, while maintaining irrigation operations wherever possible.
The drought has renewed debate over Taiwan’s water pricing and long-term supply strategy, per News and Market. While experts argue that higher water rates could encourage conservation and investment in alternative sources, officials say reliability of supply remains a greater concern for most businesses.
National Taiwan University civil engineering Professor Yu Ching-yun (游景雲) said reservoir expansion and transfer systems can help, but their effectiveness is limited during extreme droughts. He compared increased reservoir capacity to a larger refrigerator — useful for storage, but unable to solve a shortage if no new supplies arrive
Yu called for a broader reassessment of water allocation policies and Taiwan’s industrial development strategy, arguing that the agricultural sector should not be treated as a “last resort” whenever shortages emerge.
