China floods threaten collapse of world's largest dam

The China Meteorological Administration issued a "No. 1 Flood" warning as a second month of rain and earthquakes risks collapse of Three Gorges Dam and the safety of 400 million.  

Southern China in June suffered its worst flooding since 1940 with the overflowing of 250 rivers impacting 15 million residents and causing at least 121 people dead or missing.  The world's largest hydroelectric dam, the 1.4-mile-wide and 630-foot-high Three Gorges Dam on the Yangtse River with a 5-trillion-gallon capacity, fully opened its seven massive outlets to begin discharging a record 28 acre-feet per second.

But after thirty-one days of rain, a record 16.8 inches falling between Sunday and Monday morning, and inflows running at 40 acre-feet per second after, CMA on July 4 issued an 80-percent risk of thundershowers for each of the next 11 days.

China's paramount leader, Xi Jinping, in his first public statement on the crisis, called on the country to "put people first and value people's lives most in the fight against the floods," according to the Xinhua official state news agency.

Human rights advocates complained as a record 1.2 million people from 13 cities, 140 towns, and 1,350 villages were displaced as Three Gorges Dam's reservoir filled.  But some Chinese geologists also warned that impoundment water weight could create severe earthquake risk due to amplification of the region's historically low seismicity.

A 2013 academic study published in China's Geodesy and Geodynamics Journal found that a 2008 magnitude 4.1 tremblor, between the 2003 opening and the 2012 opening of the world's largest power station, revealed "the intensity and peak ground acceleration of reservoir-induced earthquakes are higher" than past tectonic earthquakes.

Later that year, Saint Louis University seismology professor Lupei Zhu, Ph.D., working with a group of scientists from the China University of Geoscience in Wuhan studying Three Gorges Dam, reported that a 5.1-magnitude "earthquake occurred almost right beneath one of our seismic stations."  Data verified that the main quake and aftershocks occurred in a narrow band along a previously unidentified fault that is connected to the reservoir.

A subsequent field survey by SLU geology professor John Encarnacion, Ph.D. found evidence that the new fault was due to deformed and damaged rocks caused by higher water levels creating greater pressure on rock pore spaces below, a known trigger for faults under stress.  Encarnacion stated: "You can feel this effect on your ears whenever you dive deeper in a swimming pool — deeper water, greater pressure."

Chinese officials have continually labeled fears that the dam could suffer a catastrophic collapse due to an overflow causing an earthquake as "nonsense," but China's internet lit up at 4:07 A.M. on July 2, when a magnitude 3.2 earthquake at an extremely shallow depth of five miles rattled Zoige County in Sichuan Province, raising concerns that embankment landslides could threaten the integrity of Three Gorges Dam.

With inflow of water to the Three Gorges Reservoir matching the peak rate of the horrific 1998 floods, the Changjiang Water Resources Commission at 10 A.M. issued an urgent warning that upper reaches of the Yangtze River would witness "No. 1 flood of 2020."

Previously, Xinhua state media claimed that rising water releases from Three Gorges, Gezhouba, Xiluodu, and Xiangjiaba dams were aimed at maximizing electrical generation. But Hong Kong newspapers alleged that "power generation" was the cover story to mask emergency flood discharges to prevent the threat of dam collapses.

The Radio Free Asia news agency spoke to a downstream resident of Hunan's Xiangyang City on June 30 who said Three Gorges Dam and Gezhou Dam were "currently in full flood relief mode."  He ominously pointed out that flood season had yet to officially begin: "The main flood season in the Yangtze river basin is usually July and August."

The China Meteorological Administration issued a "No. 1 Flood" warning as a second month of rain and earthquakes risks collapse of Three Gorges Dam and the safety of 400 million.  

Southern China in June suffered its worst flooding since 1940 with the overflowing of 250 rivers impacting 15 million residents and causing at least 121 people dead or missing.  The world's largest hydroelectric dam, the 1.4-mile-wide and 630-foot-high Three Gorges Dam on the Yangtse River with a 5-trillion-gallon capacity, fully opened its seven massive outlets to begin discharging a record 28 acre-feet per second.

But after thirty-one days of rain, a record 16.8 inches falling between Sunday and Monday morning, and inflows running at 40 acre-feet per second after, CMA on July 4 issued an 80-percent risk of thundershowers for each of the next 11 days.

China's paramount leader, Xi Jinping, in his first public statement on the crisis, called on the country to "put people first and value people's lives most in the fight against the floods," according to the Xinhua official state news agency.

Human rights advocates complained as a record 1.2 million people from 13 cities, 140 towns, and 1,350 villages were displaced as Three Gorges Dam's reservoir filled.  But some Chinese geologists also warned that impoundment water weight could create severe earthquake risk due to amplification of the region's historically low seismicity.

A 2013 academic study published in China's Geodesy and Geodynamics Journal found that a 2008 magnitude 4.1 tremblor, between the 2003 opening and the 2012 opening of the world's largest power station, revealed "the intensity and peak ground acceleration of reservoir-induced earthquakes are higher" than past tectonic earthquakes.

Later that year, Saint Louis University seismology professor Lupei Zhu, Ph.D., working with a group of scientists from the China University of Geoscience in Wuhan studying Three Gorges Dam, reported that a 5.1-magnitude "earthquake occurred almost right beneath one of our seismic stations."  Data verified that the main quake and aftershocks occurred in a narrow band along a previously unidentified fault that is connected to the reservoir.

A subsequent field survey by SLU geology professor John Encarnacion, Ph.D. found evidence that the new fault was due to deformed and damaged rocks caused by higher water levels creating greater pressure on rock pore spaces below, a known trigger for faults under stress.  Encarnacion stated: "You can feel this effect on your ears whenever you dive deeper in a swimming pool — deeper water, greater pressure."

Chinese officials have continually labeled fears that the dam could suffer a catastrophic collapse due to an overflow causing an earthquake as "nonsense," but China's internet lit up at 4:07 A.M. on July 2, when a magnitude 3.2 earthquake at an extremely shallow depth of five miles rattled Zoige County in Sichuan Province, raising concerns that embankment landslides could threaten the integrity of Three Gorges Dam.

With inflow of water to the Three Gorges Reservoir matching the peak rate of the horrific 1998 floods, the Changjiang Water Resources Commission at 10 A.M. issued an urgent warning that upper reaches of the Yangtze River would witness "No. 1 flood of 2020."

Previously, Xinhua state media claimed that rising water releases from Three Gorges, Gezhouba, Xiluodu, and Xiangjiaba dams were aimed at maximizing electrical generation. But Hong Kong newspapers alleged that "power generation" was the cover story to mask emergency flood discharges to prevent the threat of dam collapses.

The Radio Free Asia news agency spoke to a downstream resident of Hunan's Xiangyang City on June 30 who said Three Gorges Dam and Gezhou Dam were "currently in full flood relief mode."  He ominously pointed out that flood season had yet to officially begin: "The main flood season in the Yangtze river basin is usually July and August."