The dam at a small reservoir in China's Guangxi region gave way last month after days of heavy rain in a collapse that could be a harbinger of sterner tests for many of the country's 94,000 aging dams as the weather gets more extreme.
Located in Yangshuo county, famed for its otherworldly karst landscape, the dam collapsed at around midday on June 7, inundating roads, orchards and fields in Shazixi village, residents told Reuters.
"I've never seen such flooding," said villager Luo Qiyuan, 81, who helped build the dam decades ago.
"The water levels were never so high in previous years, and the dam had never collapsed."
Completed in 1965, the dam, made of compacted earth, was designed to hold 195,000 cubic metres of water, enough to fill 78 Olympic-size swimming pools and meet the irrigation needs of Shazixi's farmers.
On a visit to the reservoir in mid-July, Reuters found the length of the dam, of about 100 metres, had largely vanished. It was reinforced 25 years ago.
The water went over the dam, which then collapsed, said a member of a survey crew at the reservoir, declining to be identified as he was not authorised to speak to media.
Shazixi residents said there were no deaths.
But the collapse, which was not reported by domestic media, suggests big storms might be enough to overwhelm reservoirs, especially if the design is inferior and maintenance has been patchy.
That raises the prospect of disaster in river valleys and flood plains that are much more densely populated than they were when the dams were built.
Environmental groups say climate change is bringing heavier and more frequent rain. Massive flooding could trigger unforeseen "black swan" events, the government says, with extreme consequences.
EXTREME EVENTS
Thousands of dams were built in the 1950s and 1960s in a rush led by Mao Zedong to fend off drought in a largely agrarian China.
In 2006, the Ministry of Water Resources said, between 1954 and 2005, dykes had collapsed at 3,486 reservoirs due to sub-standard quality and poor management.
It was unclear if record-breaking rains were to blame for the Shazixi collapse or if the dam's emergency spillway had been blocked by silt or if it was a design problem.
The water resources department in the area declined to comment. The county government did not respond to a request for comment.
In Guangxi, in southwestern China, rainfall and temperatures were on average significantly higher in 1990-2018 compared with the previous 29 years, official data shows.
It's the extreme events that put dams at risk, said David Shankman, a geographer at the University of Alabama who studies Chinese floods.
"But a dam should be able to withstand extreme events even if they become regular, and when the flood is over, it should be exactly of the same quality as before the event, if the dam was properly designed and built," Shankman said.
According to a notice at the Shazixi reservoir's monitoring station, the 151.2 metre-tall dam was built with a once-every-two-century worst-case scenario in mind in which water was expected to reach 149.48 metres. Last month, it overflowed.
In the county seat of Yangshuo in June, more rain fell in three hours than usually falls in two months.
The Ministry of Water Resources did not respond to a request for comment.
In what could be another sign of trouble to come, water behind a dam on a tributary of the Yangtze river rose so sharply that authorities on Sunday were forced to blow up part of the dam to lower the level.
'BLACK SWAN'
In China's worst dam catastrophe, the Banqiao on the Yellow River, completed in 1952 with Soviet assistance, collapsed in 1975, killing tens of thousands of people, official estimates published two decades later showed.
Ye Jianchun, deputy minister of the Ministry of Water Resources, told a recent news conference he was confident flood-control projects on major rivers were capable of handling the largest floods seen since the founding of the People's Republic of China.
But Ye was not so categorical about dams on other rivers, saying excessive floods may exceed the defence capability of the engineering to result in a "black swan" event.
Aware of the risks, authorities have been reinforcing and raising old dams and stepping up inspections. New dams are planned to increase storage capacity.
North of Yangshuo at Qingshitan is the biggest dam in the area. The banks of the river into which it empties have been shored up since last month, said a workman dumping rocks and soil with a wheel loader.
But climate change is bringing a new normal of extremes and flood-risk policies decided a decade or two ago are no longer sufficient, said Benjamin Horton, director at the Earth Observatory of Singapore.
"What really needs to happen is to work with the ecosystems, not against them by building dams, by extending flood wetlands and flood plains and allowing the water to naturally mix with the environment," he said.
Reuters
Wed Jul 22 2020
An aerial view shows the flooded Yangshuo town by the overflowing Li River, against the backdrop of the karst landscape in Guangxi Zhuang Autonomous Region, China June 7, 2020 - Chen Yan via REUTERS
16 kereta, tiga rumah rosak ditimpa pokok akibat hujan lebat di KL
Dalam semua kejadian berkenaan tiada mangsa dilaporkan cedera.
Tragedi Easter: 45 maut, bas terbabas, terbakar
Kesemua yang meninggal dunia itu dilaporkan dalam perjalanan menuju perhimpunan Easter.
Pengasas FTX, Sam Bankman-Fried dipenjara 25 tahun
Bankman dituduh mencuri AS$8 bilion daripada pelanggan dan pelabur syarikat pertukaran mata wang kripto FTX yang kini telah muflis.
Melaka sasar nilai pelaburan RM10 bilion, fokus 10 sektor
Kerajaan negeri berada di landasan terbaik dengan sasaran nilai pelaburan RM10 bilion, apabila meletakkan 10 sektor industri sebagai fokus utama pada tahun ini.
Sabah akan pelbagaikan sumber ekonomi - Ketua Menteri
Sabah tidak boleh hanya bergantung kepada dagangan sumber sedia ada terutama kelapa sawit, minyak dan gas dalam membangunkan ekonomi negeri.
Sarawak perkasa industri hiliran untuk hasilkan produk kayu bernilai tinggi
Kerajaan Sarawak akan terus memperkasakan industri hiliran seperti penghasilan biojisim bagi meningkatkan lagi pengeluaran produk kayu nilai tambah tinggi.
Duta, Pesuruhjaya Tinggi Malaysia perlu mahir pelaburan, perdagangan
Menteri Luar Datuk Seri Mohamad Hasan mahu perwakilan ke luar negara iaitu Duta Besar dan Pesuruhjaya Tinggi Malaysia mahir dalam aspek perdagangan bagi membawa masuk pelaburan ke dalam negara.
Malaysia kekal komited usaha reformasi ekonomi, terima inovasi dan pembangunan mampan
Malaysia kekal komited dalam usaha mereformasi ekonomi dan pada masa sama, bersedia menerima inovasi serta pembangunan mampan, kata TPM Fadillah.
PSM adakan mesyuarat pascanilai padang SNBJ awal minggu depan
Perbadanan Stadium Malaysia bakal mengadakan mesyuarat pascanilai (post-mortem) berkenaan isu padang SNBJ pada awal minggu hadapan.
Nyawa tiada nilai, maruah pula dibuat main oleh Israel
Sudahlah kejam, jijik, tidak beradap pula. Tidak cukup dengan kekejamannya membunuh berpuluh ribu rakyat Palestin, nyawa manusia di bumi Gaza itu bagaikan tiada nilai buat mereka. Dalam beberapa video yang tular baru-baru ini, tentera Israel dengan bangganya memperolok maruah rakyat Palestin dengan bermain pakaian dalam wanita yang ditemui di rumah-rumah penduduk di situ.
Piala Thomas: Rexy tidak mahu insiden di BATC 2024 berulang di Chengdu
Pada saingan BATC, skuad lelaki mengalami detik mencemaskan selepas Lee Zii Jia dan Ng Tze Yong terpaksa direhatkan bagi beberapa perlawanan.
Hampir separuh penyelidik AI terbaik dunia berasal dari China
AS mengekang akses kepada cip terkini China bagi memastikan status sebagai negara dengan kemajuan teknologi terkini tidak akan dipintas.
China gesa Filipina henti pencabulan, provokasi di Laut China Selatan
Tentera Filipina pada Sabtu dakwa kapal pengawal pantai China menggunakan meriam air terhadap kapal bekalan Filipina di Laut China Selatan.
Penerbangan terus Shanghai-P.Pinang rangsang industri perniagaan, pelancongan negeri
Juneyao Airlines yang berpangkalan di Shanghai menawarkan empat penerbangan setiap minggu antara kedua-dua bandar berkenaan.
TikTok dianggar bernilai ASD100 bilion
Walaupun Bytedance bertegas akan menentang RUU ini jika diluluskan, beberapa kumpulan pelabur di Amerika Syarikat bersedia untuk membelinya.
PKS Malaysia sertai CISMEF, pameran PKS terbesar di China
Malaysia akan menjadi negara hos bersama CISMEF tahun ini dalam usaha mempercepatkan akses pasaran PKS Malaysia di China.
Pilih Malaysia sebagai hab, tembusi pasaran lebih luas - PM
Malaysia punya dasar ekonomi yang jelas dan berupaya sediakan segala fasiliti perniagaan bagi membantu lonjakkan pulangan ekonomi yang baik.
China bidas AS lulus RUU haramkan TikTok
Tindakan meluluskan RUU pengharaman TikTok adalah seperti membuli dan akan kembali 'menggigit Amerika Syarikat' sendiri.
AS lulus RUU haramkan TikTok
Dewan Perwakilan Amerika Syarikat (AS) yang bersidang pada Rabu meluluskan Rang Undang-undang (RUU) yang mengharamkan penggunaan aplikasi media sosial TikTok yang dibangunan China di negara itu.
'Malaysia jadi pilihan industri semikonduktor global di tengah perang perdagangan AS-China'
Malaysia dilaporkan muncul sebagai destinasi yang tidak dijangka untuk industri semikonduktor global.