Heavy rains in eastern China have put more than 660 reservoirs at risk of overflowing, an official said yesterday. Rain-triggered floods have swept parts of eastern and southern China this month, leaving at least 175 dead and 86 missing and causing 35 billion yuan ($5 billion) in direct economic losses, according to the Ministry of Civil Affairs. An official at the media department of the Anhui Water Resource Department said water levels at more than 660 reservoirs in the province were above the w arning level. Like most Chinese officials, she would give only her surname, Zhao. The official Xinhua News Agency also said in a Chinese-language report that the reservoirs were in danger of overflowing. The Anhui flood control headquarters said most of the reservoirs - more than 620 - were small, and that only three were large. Such flooding is common every year during China\'s rainy season, with reservoirs and rivers overflowing. Zhao referred further queries to the provincial Communist Party Propaganda Department, but calls were not answered there. Xinhua said the water levels of the Shuiyang and Qingyi rivers, both tributaries of the Yangtze River running through Anhui, had risen above the warning safety mark. It said many of the reservoirs in Anhui had started discharging water on orders from the state flood-control headquarters. In neighboring Zhejiang province, the operator of eastern China\'s largest reservoir opened three of its nine floodgates Tuesday because of the risk of overflowing. It was the first time the Xin\'anjiang Reservoir has been forced to discharge water since 1999, Zhejiang\'s flood control headquarters said. Xinhua quoted officials as saying the release of water into the Lanjiang River wouldn\'t cause havoc downstream because water there had receded below the danger level. Meanwhile, the world\'s biggest reinsurance company, Munich Re, said yesterday that deadly weather catastrophes in China had soared around four-fold in the last 30 years, costing its economy billions. Munich Re said in a report that the number of annual disasters including violent storms, floods, extreme temperatures, droughts and forest fires had risen to about 48 by 2010 from around 11 in the early 1980s. A company spokesman noted however that official reporting of such catastrophes would have been less t ransparent in China in the 1980s than today. Munich Re said the weather events had claimed the lives of 148,000 people and cost $422 billion dollars over the same period. The head of Munich Re\'s Georisk Research, Peter Hoeppe, said China\'s current flooding woes were only the latest in an escalating long-term trend. \"The devastating floods in China are of a dramatic dimension-a phenomenon that has unfortunately occurred in China with increasing frequency over the last few decades,\" Hoeppe said in an e-mailed message. Every year, millions of Chinese are victims of weather-related natural catastrophes. And the risk is steadily growing, for climate change harbors the potential for torrential downpours while the risk of drought in certain regions is also on the rise.\" Persistent rains since early June have swamped many areas across a wide swathe of China and the state weather bureau has forecasted continued downpours with the summer typhoon season approaching. Torrential downpours across large parts of the country last ye ar triggered the nation\'s worst flooding in a decade, leaving more than 4,300 people dead or missing in floods, landslides and other rain-related disasters. - Agencies