In a written response to the Hanoi People's Committee, the ministry said the proposal is consistent with approved national plans on disaster prevention, irrigation and water resource management.

Existing planning documents already include proposals for the Xuan Quan Weir on the Red River and the Long Tuu Weir on the Duong River.

Multiple objectives

According to the ministry, the proposed structures are intended to regulate river flows and raise water levels during the dry season to serve multiple purposes.

These include improving river landscapes and the environment, supporting inland waterway transport, tourism and related services, while ensuring sufficient water supplies for major irrigation systems such as Bac Hung Hai, Bac Duong, the Nhue River, and the Day River.

The ministry said the projects could also help restore water flow to several rivers across the Red River Delta - including the Day, Nhue, To Lich, and Ngu Huyen Khe rivers - by maintaining higher water levels in the Red River during the dry season.

Planning documents also call for studying a weir on either the Da River or the Red River to regulate dry-season flows on the Da River, ensuring adequate water intake through Luong Phu Sluice to replenish the Tich River and the Day River.

The project is also expected to optimize water use for domestic supply, agricultural production, hydropower generation and inland navigation without compromising flood drainage.

Strict technical and environmental requirements

The ministry said it supports further research into all three proposed weirs and urged Hanoi to ensure the projects deliver economic and technical benefits while strengthening water security and climate resilience.

However, it stressed that the structures must not reduce flood discharge capacity or threaten the safety of the river dike system.

Authorities must also ensure the projects do not increase disaster risks, trigger riverbank erosion upstream or downstream, lower downstream water levels in ways that affect existing water intake or drainage facilities, or cause sediment accumulation that could damage river ecosystems.

For the proposed Da River weir, the ministry emphasized that it must not affect the minimum downstream water level required for the operation of the Hoa Binh Hydropower Plant under any operating conditions.

The ministry also called on Hanoi to conduct comprehensive assessments covering river engineering, inland waterway navigation, fish migration, water quality, sediment transport and consistency with previous agreements related to the proposed Red River landscape boulevard development project.

Kieu Oanh