Wuhan is bracing itself for the arrival today of two separate flood crests, from the Yangtze River and its tributary, the Han, officials said. This season's sixth flood crest passed through Shishou city, Hubei, on Monday and is racing towards Wuhan. Its arrival is expected to be separated from the other crest by only a few hours, officials said. Water levels in Shashi - upstream of Wuhan - fell below the 45-metre danger level yesterday and authorities have temporarily held off plans to blow up dykes in the Jingjiang flood diversion zone. Xinhua said 335,000 people had been evacuated from the diversion zone, but there were reports that thousands of people had been reluctant to abandon their homes. A spokesman for the Jingjiang anti-flood command office said water levels in Shishou fell 19 centimetres yesterday after reaching a record high on Monday. All farmland in Jingjiang city areas was flooded, he said, although some residents who lived on higher ground were not affected. He denied reports that many dykes in the city had been blown up to absorb Yangtze flood water, saying that only five small levees had been abandoned two weeks ago to relieve water pressure from the Yangtze. A senior flood control engineer in Wuhan, Ge Shouye, said he was not too worried that the sixth flood crest would raise the water level, but was concerned that some dykes may become vulnerable after prolonged submersion. Mr Ge, the chief engineer of the Yangtze Water Resources Committee in the city, said the urban areas of Wuhan were not in any danger, but some embankments in the suburbs, having been under water for so long, had become soft and could breach easily. 'It will be safer if the water level can come down one or two metres,' he said. But with the flood crests coming one after another, Mr Ge said, the water levels had had no chance to reduce. In his assessment, it would be more than two weeks before the Yangtze River water level could come down.