TAIPEI (Taiwan News) — Western Taiwan recorded its driest winter in 75 years, but extensive water management measures and inter-regional transfers have helped prevent major supply disruptions despite below-average rainfall in key reservoir catchments, according to the Water Resources Agency.
In a press release, the agency said preparations for extreme weather included improved water dispatch systems and conservation measures, which maintained stable supplies for residential, industrial, and agricultural users. It described the water transfer network as a "pearl string" pipeline that strengthens water supply resilience.
The network includes water transfers from Shihmen Reservoir to Hsinchu, the Jiji Weir to Chiayi, Zengwen Reservoir to Nanhua Reservoir, and surplus water from the Kaohsiung-Pingtung Weir northward to Tainan. Total cross-regional water transfers have reached 480 million tonnes.
The agency said additional conservation measures have included reservoir discharge controls, prioritizing river and groundwater use, industrial water-saving programs, reclaimed water use, enhanced agricultural irrigation management, activation of drought-resistant wells, and adjustments to municipal water pressure.
Through coordination among government agencies, water-saving and allocation measures have conserved more than 1.04 billion tonnes of water, equivalent to roughly five times the storage capacity of Shihmen Reservoir, according to the agency.
Southern Taiwan has been particularly affected by low rainfall, with precipitation in major reservoir catchments less than 50% of the historical average during the dry season. However, the Zengwen-Nanhua interconnection pipeline and Kaohsiung's northward water transfer system have improved the flexibility of regional water distribution.
Between June and November last year, the Zengwen-Nanhua pipeline transferred approximately 13 million metric tonnes of water from Jiaxian Weir to Wushantou Reservoir for storage. From January through May this year, Zengwen Reservoir supplied about 20 million tonnes of water to Nanhua Reservoir.
In Kaohsiung, groundwater and drought-relief wells were used to supplement supplies. The Gaoping River system met local demand while providing a daily surplus of 100,000 to 150,000 tonnes to Tainan beginning in October, for a cumulative transfer of about 25 million tonnes.
The agency said southern Taiwan also continues to rely on diversified water sources, including reclaimed water, groundwater, and emergency wells. Reclaimed water use alone averages approximately 140,000 metric tonnes per day in the region, totaling about 52 million tonnes.
To improve reservoir storage efficiency and long-term water management capacity, the WRA has accelerated dredging operations during the dry season. Since December, dredging at 23 major reservoirs has removed 11.07 million cubic meters of sediment, 20% above the five-year average, per a press release.
Among the projects, Zengwen Reservoir accounted for 3.91 million cubic meters of dredged material, more than double its five-year average, helping increase storage capacity and operational flexibility.
The WRA said the combined storage of Zengwen, Wushantou, and Nanhua reservoirs in Tainan currently stands at approximately 72 million tonnes. Completion of irrigation for the first rice crop on May 31 has also reduced reservoir releases.
Current supplies are expected to maintain safe public water levels through the end of June. The agency noted that forecasts from the Central Weather Administration indicate frontal systems and the southwest monsoon are likely to bring significant rainfall during the first half of June.
The agency said it will continue maximizing water diversion and storage opportunities, strengthen inter-regional water dispatch, and activate contingency measures as conditions require to ensure stable water supplies nationwide.
