Continuously flooded, the Director of Hanoi Department of Construction proposed to build an underground tank near Sword Lake

The Director of Hanoi Department of Construction proposed to assign Hoan Kiem District People’s Committee to study and implement a plan to build an underground rainwater storage tank in the area of ​​​​Bat Dan – Duong Thanh intersection to prevent flooding.

On the afternoon of June 2, reporting at the May 2022 working meeting of the Hanoi People’s Committee, Mr. Vo Nguyen Phong, Director of the Hanoi Department of Construction, said that in the past few days, due to the influence of the low pressure trench Combined with the convergence of high winds, many places in Hanoi have moderate rain, heavy rain and thunderstorms. Typically, the night rain from May 22 to the morning of May 23, rainfall is common in urban districts from 70 to over 100 mm. In suburban districts, the total rainfall is common from over 100 mm to 230 mm.

Mr. Vo Nguyen Phong, Director of Hanoi Department of Construction, speaking at the meeting – Photo: Phu Khanh

On May 29, due to excessive rainfall on a large area, it exceeded the design capacity of the drainage system (sluice system: 70 mm/hour). Rainfall is more than 100 mm, especially in Tay Ho district over 160 mm and over 180 mm in Cau Giay, so many areas of the city are flooded from 20 to 40 cm deep, up to 50 cm in some locations.

The rain on the evening of June 1, due to the influence of convective cloud areas, rained on a large scale in the city. Areas of the district rainfall ranges from 30 to 70 mm. Partial rain occurs in the districts, the rainfall ranges from 30 to 40 mm, especially in the area of ​​Hai Boi commune, Dong Anh district, the rainfall is up to 193 mm. The time of rain is concentrated from 18:40 to 19:30. The drainage maintenance units have had enough human resources, equipment to open gas, pump drainage and guide traffic flow. By 9pm on June 1, 2022, the above points had basically drained of water and traffic was normal.

The director of the Department of Construction said that the Hanoi drainage system has only completed construction investment according to the master plan for the area: To Lich River, Lu River, Set River and Kim Nguu River with an area of ​​77.5 km2 (including 8 districts: Ba Dinh, Hoan Kiem, Dong Da, Hai Ba Trung, Hoang Mai, Tay Ho). With a rain intensity design of 310 mm/day for the entire system and 70 mm/hour for the sewer system.

The remaining areas such as: Ta Nhue, Huu Nhue, Long Bien area, Ha Dong district, Nam Tu Liem, Bac Tu Liem have not been invested and built according to the planning. For example: Lien Mac pumping station (170 m3/s), Gia Thuong, Cu Khoi pumping stations (total capacity 65 m3/s); Currently investing in Yen Nghia pumping station of 120 m3/s but not yet completed; The Nhue River has not been improved, dredging and river embankment are the main reasons for not ensuring the drainage work for the city.

According to Mr. Vo Nguyen Phong, in 2021, Hanoi has eliminated 5 inundation points (Thanh Dam; Truong Chinh; Giai Phong; Doi Can; Pham Van Dong); 5 points have reduced inundation time and depth by about 50% compared to previous years: Thuy Khue, Minh Khai, Hoa Bang, Ngoc Lam, Hoang Nhu Tiep…

However, the city still has 5 points that have not improved much in terms of flooding: Phan Boi Chau – Ly Thuong Kiet; Crossroads of Duong Thanh – Bat Dan – Phung Hung; Cao Bat Quat; Nguyen Chinh; Thang Long Boulevard collection road. The main reason is due to unfavorable terrain, far from discharge source.

To solve the problem of flooding in the inner city and some inherent areas when it rains heavily, the Department of Construction proposes to coordinate with the Department of Agriculture and Rural Development and drainage units, irrigation companies. study, propose and report to the City People’s Committee to study and propose immediate and long-term solutions such as: Investing in urban drainage and drainage pumping stations; water storage tanks in low-lying areas to reduce local flooding; invest in upgrading the drainage system in the left Nhue, Huu Nhue and the North Red River basins…

In the immediate future, research and construct additional urban drainage systems on the road collecting Thang Long Boulevard and solutions to solve local depressions in underground tunnels for people’s living.

Notably, the Director of the Hanoi Department of Construction proposed to assign the Hoan Kiem District People’s Committee to study and implement the plan to build an underground rainwater storage tank in the area of ​​​​Bat Dan 5 intersection – Duong Thanh, as he did similar to the cashew tank. Underground information on Nguyen Khuyen street, in front of Ly Thuong Kiet Secondary School.

“The flooding point at Nguyen Khuyen street, Dong Da district, through monitoring the rains in 2021, it shows that after putting the Nguyen Khuyen regulation tank into operation, it has promoted its effectiveness, inundation level and duration. Inundation has decreased significantly (about 70%) compared to 2020” – Mr. Vo Nguyen Phong said.

In addition, the Director of the Department of Construction also suggested urging the investor of the CV1 park project to speed up the construction progress of the regulating lake, making an important contribution to the regulation and service of water drainage in this area.