Why is Hanoi flooded widely even though storm No. 5 did not directly affect it?

Over the past 24 hours, the amount of rain in Hanoi after storm No. 5 was very heavy and exceeded all forecasts, causing the city's drainage system to overload, leading to a series of roads and residents in Hanoi being severely flooded.

On the afternoon of August 26, in response to widespread flooding in Hanoi due to the impact of storm No. 5 causing prolonged heavy rain, a representative of Hanoi Drainage Company Limited said that in the past 24 hours, the amount of rain in Hanoi was very heavy and exceeded all forecasts, which caused the drainage system to be overloaded, causing many roads and residential areas in Hanoi to be heavily flooded.

Statistics in the past 24 hours show that the rainfall measured in Hanoi is generally from 200 - 300mm, many places far exceeding the system's load capacity, such as: Hai Ba Trung ward over 461mm, Yen So 368mm, Tay Mo 352mm, Yen Nghia 334mm, O Cho Dua 323mm... and many other places.

Meanwhile, according to the authorities' calculations for the central area (To Lich river basin, inside belt 2 and belt 3), if the rainfall exceeds 310mm in 48 hours, the risk of flooding is very high, but in the past 24 hours, many points recorded rainfall of over 350mm, far exceeding the warning threshold.

Heavy rain caused many streets in Hanoi to be seriously flooded

The representative of Hanoi Drainage Company Limited also said that as of the same afternoon, dozens of flooded areas had been recorded in Hanoi, from the inner city to the suburbs, such as: Duong Dinh Nghe - Nam Trung Yen street area, My Dinh - Thien Hien intersection, Hoa Bang street (lane 99), Vo Chi Cong street (UDIC Building), Huynh Thuc Khang street (Nguyen Hong intersection - lane 14 Huynh Thuc Khang), lane 165 Thai Ha street, Ngoc Lam street, To Huu street (from Luong The Vinh to Trung Van). In particular, underpasses No. 1, No. 5, No. 6, Km9+656 Thang Long Avenue were deeply flooded.

Floodwaters flooded an apartment complex in Co Nhue ward.

Heavy rain causes flooding at Trieu Khuc Primary School

To respond to and handle the flooding situation, Hanoi Drainage Company has activated the 24/24-hour on-call mode, mobilizing 100% of its staff, with more than 2,000 officers and workers spread across key areas. The entire drainage system of Hanoi has been operating at maximum capacity. Of which, Yen So pumping station has operated 20/20 units, with a capacity of about 90m³/s.

Pumping stations Dong Bong 1, Dong Bong 2, Co Nhue, and large regulating lake systems such as Bay Mau, Dong Da, Truc Bach, and Giang Vo all opened their sluice gates and operated synchronously to lower the water level. Hundreds of intake and discharge stations were also staffed by workers, dredging trash to ensure the fastest drainage.

Authorities of Hanoi Drainage Company are handling a "hot spot" of flooding.

By late afternoon of the same day, heavy rain was still falling in Hanoi. Hanoi Drainage Company continued to warn of the risk of flooding in many areas of Hanoi, especially in suburban and border areas due to unsynchronized drainage infrastructure, lack of pumping stations and regulating lakes. In addition, partly due to the unfinished Yen Nghia pumping station project.

MINH KHANG

Source: https://www.sggp.org.vn/vi-sao-ha-noi-ngap-lut-dien-rong-du-bao-so-5-khong-anh-huong-truc-tiep-post810281.html