VietNamNet Bridge – Experts have said that the more the city tries to prevent flooding, the worse the flooding becomes in Hanoi.

The management capacity and planning work are two of the reasons behind the faulty drainage system.

The heavy rains throughout Tuesday night caused severe flooding in many places in Hanoi. Local people were in misery after a downpour.

Heavy rain on the night of May 24 submerged many streets in Hanoi. Thang Long Highway was under 60-70cm of water and the city’s entire traffic network was paralysed the next morning. Traffic on Tran Thai Tong and Vu Trong Phung saw flooding of 30-60cm. Some areas had still not recovered by 5pm.

Locals struggled to protect their belongings as the ground floors of many houses were also submerged. Minh Chien, a local in Cau Giay District, said he woke up at 2am because of shouts from neighbours.

After the downpour, Vo Nguyen Phong, Director of the Hanoi Department of Construction, said that the rainfall exceeded the drainage capacity of Hanoi.

Phong said the rains created 35 sites of flooding. "The highest rainfall was up to 280 mm (in 5 hours). This was one of the heaviest rains in the last few years,” Phong said.

Deputy Director of the National Centre for Hydro-meteorological Forecasting Le Thanh Hai said, "Similar heavy rains are projected to come in the next two days with rainfall ranging from at least 50mm to 100mm. Normally we have five to seven rains like that in a year."

Vo Tien Hung, director of Hanoi Water Drainage Company, said the heavy rain was taxing the city's incomplete drainage system. "Rainfall from 11pm to 5am reached over 270mm. We had sent out 1,500 employees with equipment to deal with the situation," he said.

According to Hung, employees were sent to clean up the streets so that rubbish wouldn't block sewers and pump stations had worked at 100% capacity. Yet it didn't help much.

Mr. Le Vu Quang Suong, Deputy Director of the Hanoi Drainage Limited, said that the downpour was unusual, exceeding the capacity of the drainage system of Hanoi.

According to Suong, Hanoi’s drainage system is divided into two large basins: To Lich River (77.5 km2), which is being renovated with capacity of 310 mm/2 days and Ta Nhue River.

It was abnormal that flooding was serious even in the newly built residential areas. This is explained by the rapid development in My Dinh and Me Tri, where the drainage system runs to Ta Nhue River, which does not have detailed planning.

In other areas, although drainage planning has been made, these systems are not connected with each others so partial flooding has occurred.

Architect Tran Huy Anh from the Vietnam Association of Architects said traffic chaos was caused by flooding after the heavy rains on May 25 indicated that Hanoi’s urban drainage planning was not good.

Prof. Nguyen Van Hung - former Rector of the Hanoi University of Construction - said that Hanoi is flooded after every heavy rain because drainage system planning has not kept up with the speed of urbanization. Also, the sidewalks and roads are paved and lakes have become smaller.

To deal with flooding, Hanoi is implementing a huge drainage project funded by Japanese ODA. This project kicked off in 2006 and was scheduled for completion in 2014. However it is still ongoing at this moment. Because of the low pace of construction, the investment has rocketed from VND6,500 billion to more than VND8,000 billion.

Linh Nhat