Nearly 400,000 soldiers and civilians rushed to reinforce Harbin's crumbling embankments yesterday in preparation for the third flood crest to pummel the northeastern industrial city this summer. President Jiang Zemin expressed his concern on state television yesterday for the 'critical' flood situation in the northeast. 'Civilians and the army should be on emergency mobilisation to ensure the safety of Harbin, the Daqing oil fields and people's lives,' he said. Vice-Premier Wen Jiabao, who arrived in the northeast to guide the flood control exercise, told soldiers of the stakes in fighting the floods. 'At our backs are the crucial cities of the north - Harbin, Qiqihar - and our country's greatest oil field, Daqing,' Mr Wen, standing near a dyke and using a bullhorn, was seen telling the soldiers yesterday on state television. The dyke breach that sent shallow water through Harbin on Tuesday was almost fully repaired, but the swollen Songhua River was still seeping through the 26km auxiliary embankments yesterday, leaving streets ankle-deep in water. Though the full impact of the flood crest is not expected until noon today, water levels yesterday shot up 16cm from Wednesday's level, reaching a record 120.74 metres. An emergency flood diversion plan - similar to the one prepared for Hubei province that has forcibly displaced at least 500,000 people - will be put into effect if water levels hit 120.85 metres. The Government is prepared to protect Harbin, a city of nine million, by letting floodwaters leak through a 500-metre-wide gate on the north dyke in the Wanbaozhen section of the Songhua and inundate the surrounding farmland. The plan, which may lower water levels by 22cm, was revealed by Liu Chenwei, deputy secretary-general of the Harbin municipal government. In Daqing, authorities continued the battle to contain floodwaters that have inundated 2,500 oil wells and shut 500. Soldiers and civilians yesterday finished building a temporary dyke about five kilometres in front of the third one, the China News Service said. Authorities hope the temporary dyke will slow floodwaters before they hit the third layer of dykes, the last defence for Daqing's urban areas. All rail traffic has been halted since the Harbin-Daqing line was destroyed by floods.