Along with the expansion of administrative boundaries, the fast speed of urbanization has put pressure on the river and lake systems in Hanoi, prompting the city's authorities to revive its rivers and lakes to ensure environmental harmony.

A corner of West Lake and Truc Bach Lake. 

According to statistics, Hanoi leads the country in the number of rivers and lakes, with 122 lakes in the inner city, 185 lakes on the outskirts and 13 rivers flowing through its territory.

The rivers and lakes have great effects in regulating and supporting the urban drainage system, avoiding local flooding. Moreover, the lakes in the inner city, attached to the surrounding architectural space, create their own identity for Hanoi.

However, due to the rapid urbanization pace, the rivers and lakes are heavily polluted. According to monitoring data of the Division of Environmental Protection under the Hanoi Department of Natural Resources and Environment, water quality in urban rivers such as Kim Nguu, To Lich, Set, Nhue, Lu and others is worrisome, with ammonium, coliform, phosphate conents exceeding the allowed limits.

To handle this situation, in 2013, Hanoi put the Yen So waste water treatment plant in Hoang Mai district into operation. The plant has the capacity to treat 200,000 cubic meters (m3) of wastewater of the Set and Kim Nguu rivers per day. The treated water meets the set standards and is discharged into the environment.

Then, in early October of 2016, Hanoi started construction of the Yen Xa waste water treatment plant in Thanh Tri district. With a capacity of 270,000 m3 per day, the plant is expected to be completed by 2019 and will treat household wastewater in Ba Dinh, Dong Da, Thanh Xuan, Hoang Mai, Ha Dong, Cau Giay and Thanh Tri districts.

In addition, Hanoi is going to implement many projects worth trillions of dong to collect and treat wastewater such as the urban wastewater collection and treatment system in Ha Dong and Son Tay districts, with respective capacity of 45.000m3/day and 20,000 m3/day; Phu Do wastewater collection and treatment system with a capacity of 84,000m3/day.

Up to now, there are six wastewater treatment plants put into operation in the city. Some other projects have been urgently implemented, such as wastewater collection and treatment plant system in Yen Xa, Son Tay, Phu Luong and so on.

Moreover, Hanoi has also made efforts to renovate the embankment, dredge and construct a scenic route around the lakes, some of which have been built with sewerage systems, fountains and sewage pumping stations. 

The lakes after renovation has solved the issues of land encroachment, construction waste, dumping waste into the lake, sanitary conditions around the lake, improving water quality.

However, the lakes are still polluted by sources of waste from living and business establishments. Therefore, from September 2016 to now, Hanoi has focused on treating water environment with Redoxy-3C, which has been more effective than expected. This is a breakthrough in environmental improvement.

Up to now, Hanoi has treated 87 inner-city lakes and 44 suburban lakes, and dredged eight lakes (Giap Bat, Ngoc Lam Park, Cau Tinh, Kim Lien, Truc Bach, Hoan Kiem and Den Lu) to keep these lakes clean.

With the targets of maintaining the quality of the lake water after treatment and creating beautiful scenery, Hanoi has installed aquatic lifebuoys on 56 lakes and aerators on 36 lakes. The specialized units are also implementing the project to embellish the landscape of West Lake and the environment of Hoan Kiem Lake.

Hanoitimes