Water Resources Agency: Extreme flood caused Mata'an Creek disaster, unrelated to open levee design
The Water Resources Agency announced that the disaster at Mata'an Creek caused by a typhoon was primarily due to an extreme flood overflow from a landslide dam, not related to the design of the open levee downstream. They explained that the extreme flood flow far exceeded protection standards.
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- 📰 Published: May 3, 2026 at 13:26
- 🔍 Collected: May 3, 2026 at 13:31 (5 min after Published)
- 🤖 AI Analyzed: May 3, 2026 at 13:45 (13 min after Collected)
Central News Agency
(Central News Agency reporter Chao Min-ya, Taipei on May 3rd) In response to media reports questioning the design of downstream open levees causing damage in Guangfu Township, Hualien, due to a landslide dam overflow in the upper reaches of Mata'an Creek during Typhoon Huajia, the Ministry of Economic Affairs Water Resources Agency today clarified that the main cause of this incident was extreme flood flow exceeding standards, unrelated to the open levee design.
The Water Resources Agency stated in a press release that open levees are a common flood control design used in Japan and Taiwan. A total of 65 open levees are designed in Taiwan's centrally managed rivers, primarily functioning to mitigate downstream flooding and allow drainage to smoothly merge into rivers during normal times.
The Water Resources Agency explained that the Guangfu Levee of Mata'an Creek was constructed according to a 100-year recurrence interval protection standard, with the right bank retaining an open levee. This open levee is not a damaged breach but a flood control structure conforming to the governance plan, and its elevation design meets the protection standard for a century-level flood. Its open levee elevation is equivalent to the planned water level of the levee, not a levee breach.
The Water Resources Agency pointed out that based on the division of labor from the 'Council of Agriculture Mata'an Creek Landslide Dam Special Project Team' working meeting on September 8th, 114 (2025), the Ninth River Management Office of the Water Resources Agency completed emergency dredging, reinforcement of the Guangfu levee body, levee heightening, and closure of the Guangfu levee's open section up to the planned levee crest height by September 21st, as per the division of labor.
The Water Resources Agency stated that according to the appraisal report by the independent third-party 'National Federation of Chinese Hydraulic Engineers Associations,' the overflow discharge from the landslide dam reached 8,860 CMS (cubic meters per second), exceeding the protection standard of 2,040 CMS. Furthermore, the overflow was not a simple flood but a super-flood carrying a massive amount of sediment, huge boulders, and driftwoods, forming high energy, high flow, high velocity, and a large mixture of rock and soil. This instantaneously destroyed the Mata'an Creek Bridge and caused comprehensive overflow and damage to the levees on both left and right banks, a complex disaster that could not be prevented by the Mata'an Creek levees, any other artificial facilities, or disaster prevention/mitigation measures.
The Water Resources Agency stated that after the landslide dam overflow caused the disaster, in addition to levee damage, the average riverbed siltation was about 3 to 5 meters, with over 10 million cubic meters of siltation. The Water Resources Agency immediately established a forward command post on the same day to complete emergency rescue and dredging and other post-disaster treatment measures. The Water Resources Agency has fully mobilized its 14 subordinate offices to deploy a large number of personnel and equipment to fully support disaster relief and is committed to undertaking reconstruction projects, levee strengthening and heightening, and emergency dredging work to prevent secondary disasters.
The Water Resources Agency emphasized that while it respects the families' right to seek national compensation through legal procedures, the main cause of this disaster was extreme natural conditions, and it was unrelated to the open levee design. It hopes that all sectors of society will base their discussions on accurate information and not disseminate erroneous messages. (Edited by Tsai Su-jung) 1150503
(Central News Agency reporter Chao Min-ya, Taipei on May 3rd) In response to media reports questioning the design of downstream open levees causing damage in Guangfu Township, Hualien, due to a landslide dam overflow in the upper reaches of Mata'an Creek during Typhoon Huajia, the Ministry of Economic Affairs Water Resources Agency today clarified that the main cause of this incident was extreme flood flow exceeding standards, unrelated to the open levee design.
The Water Resources Agency stated in a press release that open levees are a common flood control design used in Japan and Taiwan. A total of 65 open levees are designed in Taiwan's centrally managed rivers, primarily functioning to mitigate downstream flooding and allow drainage to smoothly merge into rivers during normal times.
The Water Resources Agency explained that the Guangfu Levee of Mata'an Creek was constructed according to a 100-year recurrence interval protection standard, with the right bank retaining an open levee. This open levee is not a damaged breach but a flood control structure conforming to the governance plan, and its elevation design meets the protection standard for a century-level flood. Its open levee elevation is equivalent to the planned water level of the levee, not a levee breach.
The Water Resources Agency pointed out that based on the division of labor from the 'Council of Agriculture Mata'an Creek Landslide Dam Special Project Team' working meeting on September 8th, 114 (2025), the Ninth River Management Office of the Water Resources Agency completed emergency dredging, reinforcement of the Guangfu levee body, levee heightening, and closure of the Guangfu levee's open section up to the planned levee crest height by September 21st, as per the division of labor.
The Water Resources Agency stated that according to the appraisal report by the independent third-party 'National Federation of Chinese Hydraulic Engineers Associations,' the overflow discharge from the landslide dam reached 8,860 CMS (cubic meters per second), exceeding the protection standard of 2,040 CMS. Furthermore, the overflow was not a simple flood but a super-flood carrying a massive amount of sediment, huge boulders, and driftwoods, forming high energy, high flow, high velocity, and a large mixture of rock and soil. This instantaneously destroyed the Mata'an Creek Bridge and caused comprehensive overflow and damage to the levees on both left and right banks, a complex disaster that could not be prevented by the Mata'an Creek levees, any other artificial facilities, or disaster prevention/mitigation measures.
The Water Resources Agency stated that after the landslide dam overflow caused the disaster, in addition to levee damage, the average riverbed siltation was about 3 to 5 meters, with over 10 million cubic meters of siltation. The Water Resources Agency immediately established a forward command post on the same day to complete emergency rescue and dredging and other post-disaster treatment measures. The Water Resources Agency has fully mobilized its 14 subordinate offices to deploy a large number of personnel and equipment to fully support disaster relief and is committed to undertaking reconstruction projects, levee strengthening and heightening, and emergency dredging work to prevent secondary disasters.
The Water Resources Agency emphasized that while it respects the families' right to seek national compensation through legal procedures, the main cause of this disaster was extreme natural conditions, and it was unrelated to the open levee design. It hopes that all sectors of society will base their discussions on accurate information and not disseminate erroneous messages. (Edited by Tsai Su-jung) 1150503