Unique design of the first spillway on To Lich River

Over the past four months, Hanoi has been continuously implementing many projects with the goal of improving the environment and urban sanitation, and restoring the natural ecosystem in the To Lich River basin. One of the outstanding and attention-grabbing projects is the Thanh Liet dam - the first project in a series of three dams on the To Lich River that is gradually taking shape with a unique design.

Construction began in mid-February 2025 in the Quang Bridge area, Thanh Liet Dam has the function of regulating the flow, stabilizing the water level and supporting the cleaning of the river water. Not simply a hydraulic structure, this project is also an experiment combining modern technology and architectural art, aiming to "revive the dead river" with sustainable solutions for both the environment and landscape.

The dam design consists of two layers of interconnected dams, which operate similarly to spillways or control sluices, allowing water level control depending on the season and operating conditions.

When water retention is required, the dam can be closed to increase the water level, ensuring a minimum flow rate. When water discharge is required, the system can be opened flexibly to avoid stagnation.

The special feature of the Thanh Liet dam design is the octagonal observation tower built right in the middle of the dam – an unprecedented architecture on Hanoi’s inner-city rivers. The observation tower is supported by large concrete pillars, which is the central point for monitoring and checking the flow, water level and changes related to the water environment.

The octagonal house is built with eight sturdy concrete columns, a roof covered with imitation tiles, and gold-painted decorative details creating an ancient highlight mixed with a modern touch.

In the future, the observatory can become a place to stop and enjoy the scenery on both sides of the To Lich River, part of the ecological corridor and riverside public space that the city is orienting to develop.

From afar, the building looks like a gazebo in the middle of the river, opening up a viewing space for locals and tourists.

The construction unit built solid steel walls around the construction area, leaving about 8 meters of riverbed to ensure uninterrupted flow. This structure not only facilitates construction but also maintains water circulation throughout the construction period.

The construction atmosphere in early July was urgent. Workers and specialized machines and equipment worked continuously to ensure progress.

According to plan, Thanh Liet dam will be completed before August 2025, synchronized with the construction process of the two remaining dams at Dau bridge (old Hoang Mai district) and Cot bridge (old Cau Giay district).

In addition to dam construction, projects such as dredging the riverbed, clearing mud, and reinforcing both banks to prevent landslides are also being implemented in parallel to create comprehensive changes for the To Lich River.

Source: https://baolangson.vn/thiet-ke-doc-la-cua-dap-tran-giu-nuoc-dau-tien-tren-song-to-lich-5052238.html