A planned reservoir on the upper reaches of the Nen River would have cut flooding in Heilongjiang province, the China Youth Daily said yesterday.
Experts said that had the reservoir at Nirji been built, it could have controlled waters in more than a fifth of the Nen River basin.
The reservoir would reduce the discharge of the Nen River by 5,000 cubic metres per second, which would have saved Qiqihar and the Harbin-Manzhouli railway from flooding.
Officials have said it could take the industrial hub of Qiqihar in Heilongjiang three years to recover.
The reservoir could also have trimmed 0.4 metres off the Songhua River's biggest flood crest, making a crucial difference to Harbin, the newspaper said.
Heilongjiang, especially its rural villages, suffered huge damage. The flooding damaged 750,000 homes, affecting 8.5 million people, of whom 500,000 are now living in the open.