Severe Water Inrush Accident Flooded the Plant & Adjacent Stores, Hydropower Station Safety

At 1.40pm on January 12th, a major water inrush occurred at a hydroelectric power station in Sichuan province. This left 11 maintenance workers trapped, 9 of whom died during the accident. A nearby hardware store owner recalled that on the day of the accident, he and an employee were busy working inside while his 10-year-old daughter was playing in the store. All of a sudden, he felt the earth tremble and saw a tidal wave of water rushing out of the power station, rumbling as if there was an earthquake. After a few seconds of shock, he immediately rushed out of the store along with his daughter, evacuating to a nearby hillside along with several other panicking civilians. This sudden flash flood came and went, leaving destruction in its wake. Another man, who was the owner of an ironworks close by, said that the ground trembled during the flood, with waves up to 3-4 meters tall. The surveillance camera shows that the water suddenly gushed out of the hydroelectric station, creating the flash flood and leaving the nearby roads and residential areas inundated. The flooding left floating debris across the streets, with many of the cars being submerged. It wasn't until the evening of the 12th did the water eventually recede. From this description, many people will find it odd that there would be so many commercial and residential buildings near such a hydroelectric station. Why would a hydroelectric power station be so close to town? This station, the Guangzhou Hydropower Station, is located around 1.7 kilometers upstream of Danba County. Unlike the commonly seen impoundment dams such as the Hoover Dam, the Guangzhou Station is a diversion power plant, which means that it creates an artificial canal, which redirects all or a portion of the river flow for hydroelectric use. Compared to impoundment dams, these diversion plants tend to have smaller reservoirs, with relatively less change to the overall river flow. As they do not need as big of a reservoir, they tend to be situated farther from the primary water source. In the case of the Guangzhou Hydroelectric Power Station, its reservoir is located about 18 kilometers from the Xiaojin River, and has a total capacity of 3.3 million cubic meters. Via a pipeline, it is connected to the which has a rated head of 240 meters, and has three generators, each with a total power capacity of 80 megawatts. According to official sources, the cause of the sudden flooding was the bursting of a temporary valve used during maintenance of the hydropower station. 11 maintenance workers were trapped in the engine room on the second basement level. Two workers were located by the turbine ports, four were in the first unit's generator room, three were in the lowest floor of unit number three, where the water leaves the power plant, and the last two were operating the overhead crane. As such, those two were the only ones to be rescued from the power plant. After the incident occurred, the local government quickly organized a rescue team of over 500 people to contribute to disaster relief. According to the person organizing the rescue operations, the second unit was functioning normally at the time of the incident, while the first unit was undergoing additional maintenance. Due to subsequent snowfall and cold weather, paired with the narrow entrances of the power plant, rescue efforts have been proven challenging. The flooded hydroelectric power plant consists of three floors, with a length of 88.4 meters, a width of 49.7 meters, and a height of 14.6 meters, totaling 64,144 meters cubed in volume. The elevation difference between the turbines and the outflow totals 8 meters, which causes the water to surge back. As such, the gates were deformed by the water's impact, making the drainage of the water extremely difficult. Eventually, on the 13th, the water in the power plant was finally drained. According to a reporter that followed the rescuers, a large number of equipment was damaged by the impact of water, and the ground was scattered with many different concrete blocks and rubble, some greater than two meters in diameter. On the ground floor, many of the walls had collapsed under the impact of the water, exposing the steel bars underneath. This goes to show how powerful the impact of the water was at the time, and as such, none of the remaining nine workers who were on the lower floor survived. One of the power plant employees who partook in the rescue efforts told reporters that the maintenance staff who died during the accident were from a different company and were working overtime. On that day, he heard a loud noise and decided to run out to check, only to realize that the area he was just in a few seconds ago had been hit by the water. Looking back, he commented that, if I had been even a bit slower, it would have been too late for me. He also recalled that prior to the accident, the maintenance workers had warned the person in charge of installing the plug valve that there would be a risk of leakage without any reinforcement. The company had also confirmed that there was an expert at the hydroelectric power plant at the time, but they did not put too much thought into the risks as they were in a hurry to generate electricity, and the valve manufacturers had signed an agreement guaranteeing quality control. From all this information, we can conclude that there were four major issues that contributed to the accident. First, the risk factors involving the placement of such a major hydroelectric power station so close to densely populated settlements are much too high to be justifiable, as was seen from this flooding incident, which devastated the surrounding households. Second, the valve was not reinforced at all, showing the lackluster quality of the manufactured materials. Third, the management staff was either inexperienced or negligent in assessing safety. After the maintenance workers reported the lack of reinforcement in the valves, the managers of the power station paid little attention to their concerns, though partially that confidence came from the manufacturer's assurance of quality. Finally, it can't be forgotten that the maintenance was also extremely rushed, as they were in a hurry to generate electricity and ended up ignoring safety hazards, which led to the deaths of nine people and the destruction of many households. The management's disregard for the lives of these workers is clearly evident from this incident. On January 15th, the Sichuan government issued an emergency notice on strengthening the safety guidelines of provincial hydroelectric power stations, stating that the Guangzhou hydroelectric power station accident has revealed the issue of unsound safety management systems, inadequate hazard solutions, and the negligent safety inspections among the hydroelectric power stations throughout the province. The company's main goal is to provide the best possible service to its customers, and that cannot be done without proper safety regulations. The problem with the Chinese government's so-called safety management is that the government officials do not actually care about the safety of companies and their workers, as they are able to collect substantial amounts of money from fines after an incident. As such, the officials stand to gain money from the lack of safety management in companies. Due to the rampant corruption among officials, the increased emphasis on safety management just means that companies spend more money on bribes, resulting in less resources being invested into actual safety and risk prevention. According to official media reports, there are over 47,000 small hydroelectric power stations throughout China, with more than 5,000 being situated in Sichuan alone. It is difficult to estimate how many of these small hydroelectric power stations have similar safety problems. Such health and ecological hazards associated with these small power stations may prove to become a long-term issue that will be challenging to solve.