In order to carry out the task of renovating, embellishing and improving the environmental quality of To Lich River, the Hanoi Agricultural and Technical Infrastructure Construction Investment Project Management Board is urgently implementing many important items and recording positive initial results.
One of the key contents is to add a wastewater collection system on both sides of the To Lich River to the Yen Xa Wastewater Treatment Plant. As of August 15, 2025, all 245 discharge gates have been completed, exceeding the city's assigned schedule.
On July 10, 2025, the Department of Agriculture and Environment issued Environmental License No. 976/GPMT-SNNMT to Yen Xa Wastewater Treatment Plant with a capacity of 270,000 m3/day and night, allowing trial operation from August 1, 2025.
Currently, the plant processes about 200,000 m3/day and night, ensuring thorough treatment of wastewater along the To Lich River. In parallel with wastewater treatment, the Hanoi City Infrastructure and Agricultural Construction Investment Project Management Board has also completed 19 renovation locations in the section from Cau Giay to Hoa cap Bridge (Lang Ha - Le Van Luong Street) and handed it over on August 25, 2025.
This renovation contributes to improving the landscape space, creating a new look for the river, which is closely associated with urban life.
3 other key items include the construction of dams downstream of Quang Bridge, a water pipeline from West Lake to To Lich River and a post-treatment water supply system from Yen Xa Factory to the river, which is currently over 95% complete.
Due to the impact of heavy rain, storm Kajiki and the need to serve drainage for the city during the A80 Festival, the construction progress had to be suspended for about 3 weeks. After September 2, 2025, the completed construction work was urgently resumed.
According to the plan, before September 10, 2025, the water from West Lake will be brought to To Lich River; before September 20, 2025, the dam and additional water supply from Yen Xa Factory will be completed with an initial flow of 200,000 m3/day and night, then gradually increased to the designed capacity of 270,000 m3/day and night.
Regarding water quality, after stopping the discharge of water from West Lake on September 3, 2025, To Lich River is maintained at a low water level thanks to the operation of the floodgate at Cau Quang dam to ensure drainage during the rainy season. Through on-site inspection, the water quality on the river has improved significantly, and the bottom can be seen in some sections.
Before the widespread information about the river water pollution returning after September 2, the Hanoi City Infrastructure and Agricultural Construction Investment Project Management Board affirmed that it was inaccurate and caused misunderstanding among the public.
After September 3, the city temporarily stopped supplying water from West Lake to To Lich River to prioritize drainage during the rainy season. At this time, in some areas under construction, such as the Nga Tu So section, there is a temporary flow phenomenon, causing the water to turn darker.
However, this is a local, short-term phenomenon, not reflecting the situation of the entire river. In particular, in September, when the project is completed, this phenomenon will end.
In addition, people can also clearly feel the difference between the sections of rivers that have been collected with wastewater and the sections that temporarily receive wastewater directly.
