Hanoi Construction Department has identified 23 flood black spots in the city during this rainy season.
The department said the city\'s waterways and sewerage system have become choked with rubbish and silt, which exacerbates the risk of flooding in the rainy season.
When rainfall exceeds 100mm, officials said they expect major intersections in the centre of the city such as Tran Hung Dao and Phan Chu Trinh, Ly Thuong Kiet and Phan Boi Chau, and Ba Trieu and Nguyen Du to flood.
Officials from the department said they hope ongoing sewerage projects to be completed before the monsoon season. When completed, the drainage system would be able to cope with rainfall of 310mm over a two-day period, they said.
Hanoi has 56 lakes that help to relieve flooding. The city also has access to pumps, the largest of which can drain 90 cu m of water per second.