On January 15, the Ministry of Natural Resources and Environment (MONRE) issued a document giving its opinion on the investment policy for the construction of an emergency project to supplement water from the Red River to the To Lich River, according to the proposal of the Hanoi People's Committee.
According to the Ministry of Natural Resources and Environment, to fundamentally solve the problems of the To Lich River, ensure the riverside landscape, and be consistent with the planning of the capital Hanoi and specialized planning, it is necessary to add water to the To Lich River with a flow rate of about 15-20 m3/s, maintaining an average speed on the river of about 0.2-0.3 m/s.
The Vietnam Institute of Water Resources (National Key Laboratory of River and Sea Dynamics) is researching a plan to restore and connect the To Lich River, West Lake and the Red River through a system of pumping stations and non-pressure channels.
The plan of the Institute of Water Resources is to take water from the upstream area of the Red River rock bank, Tay Ho district, about 1.5 km from Nhat Tan bridge, at the position between two river regulation dykes built by the Ministry of Transport from 1992 to 1997. The items outside the river bank also include a 10-hectare natural settling lake, a channel, and a pumping station with a capacity of 18 m3/s.
River water is led through the dike into West Lake, then through the canal to the sluice gate into To Lich River, about 4 km long. On To Lich River, there is a dam downstream of Quang Bridge to raise the water level, create flow, exploit the landscape on both sides of the river, and waterway traffic. The total preliminary investment of the above plan is nearly 500 billion VND, the annual operating cost is about 25 billion VND.
The Ministry of Natural Resources and Environment commented that the plan of the Vietnam Institute of Water Resources has the same total estimated investment and construction time as the plan proposed by Hanoi, but the maximum amount of water that can be added is 18 m3/s. Thus, the preliminary plan of the Institute of Water Resources can meet the goals of restoring water resources, creating landscapes, and maintaining the flow of the To Lich River.
The Ministry of Natural Resources and Environment requested Hanoi to supplement the assessment of the risk of landslides and sedimentation in the Red River area at the water intake of the unit pumping station to ensure long-term stability of the project and continuous water intake in the condition that the water level of the Red River is increasingly decreasing.
Hanoi City needs to consider additional research on secondary pollution to the To Lich River (due to the Red River's high silt content) and waste at three dams on the river during operation; at the same time, consider and supplement solutions to pre-settle the Red River water before discharging it into the To Lich River.
The project of bringing water from the Red River to the To Lich River by a D1200 mm pressure pipeline along Vo Chi Cong Street with a length of about 5.5 km also needs to be studied and have specific solutions to address risks such as damage to underground works during construction; and pipeline breakage during operation.
