An ambitious $600 million planed to revitalize Hanoi's western rivers

The plan to pump water from the Da River to the Tich, Nhue, and Day to revive these rivers in western Hanoi may cost the city about VND16 trillion-VND17 trillion (US$627-$666 million).

This estimate was presented by expert Nguyen Truong Duy from the Vietnam Association for Large Dams and Water Resources Development at a workshop on water security solutions for western Hanoi on March 3.

Duy proposed taking 100 m3/s of water from the Thuan My sluice gate in Ba Vi District and releasing it into the Tich River. The water would flow to Son Tay Town, where a regulating dam would send 40m3/s to the Tich and Bui rivers, while the remaining 60m3/s would be diverted through the West Thang Long canal system to the Day and Nhue rivers.

"This solution will maintain a sustainable natural flow, improve the environment and promote public health, while boosting water transportation and tourism," he said.

The project will provide water for 70,000 hectares of farmland, reduce electricity costs by eliminating the need to pump water from the Red River, and supply water to 20,000 hectares of aquaculture and clean water plants, reducing the reliance on underground water, he said.

Do Van Thanh, former Director of the Institute of Water Resources Planning, suggested that the fundamental solution is to build two dams on the Red and Duong rivers to raise water levels.

This solution will ensure water supply for key irrigation projects in western Hanoi, such as the Trung Ha and Phu Sa pumping stations and the Cam Dinh and Lien Mac gates," he said.

Hanoi should upgrade its major irrigation systems, including Phu Sa-Dong Mo and those built along the Nhue and Day rivers, he added.

According to Thanh, the comprehensive plan includes raising the water level of the Red River to replenish the Nhue and Day rivers, raising the level of the Da River to feed the Tich River, and operating major pumping stations such as Trung Ha, Phu Sa, and Dan Hoai.

Under an approved plan, the Xuan Quan dam in the Van Giang District of Hung Yen province and the Long Tuu dam in Dong Anh District of Hanoi will be built to support this process.

Professor Dao Xuan Hoc, Chairman of the Vietnam Water Resources Association, said the construction of the two dams to revive the depleted rivers is a feasible measure.

Lieutenant General Nguyen Van Huong, former Deputy Minister of Public Security, suggested exploring alternative construction materials to reduce sand exploitation and help restore river ecosystems. 

"Water-related projects should be legally regulated to ensure sustainability," he said.

Dying rivers in western Hanoi

There are nine rivers flowing through Hanoi, eight of which are in the western part of the city.

This vast area includes three districts, one city, and 12 rural districts, covering 233,570 hectares with a population of 3.4 million and 147,000 hectares of agricultural land.

Among these rivers, the Tich, Bui, and Day rivers are used for irrigation, while the To Lich and Nhue rivers are used for drainage.

In recent years, many rivers west of Hanoi have experienced severe water shortages and pollution. The once mighty Day River is now almost "dead."

The continued decline of the Red and Da Rivers has pushed Hanoi's western irrigation system to critical levels, according to Thanh, former director of the Institute of Water Resources Planning.

The bed of the Da River at the Trung Ha Bridge, which connects Hanoi's Ba Vi District with Phu Tho Province's Tam Nong District, has dropped six meters since 2001. Meanwhile, the section of the Red River flowing through Son Tay Town has dropped more than seven meters. The reasons include sediment retention in upstream reservoirs, extensive socio-economic development activities, and excessive illegal sand mining.

"As a result, several irrigation systems along the Red and Da rivers have dried up and become inoperable. Examples include Luong Phu, Trung Ha, Cam Dinh, Dan Hoai, Lien Mac, and Hong Van," Thanh said.

He cited monitoring data showing that the Nhue River irrigation system, which supplies water to 61,600 hectares of farmland, is struggling to get water through the Lien Mac floodgate due to the Red River's falling water level.

Between January and February, water intake became increasingly difficult. In 2020, the sluice gate was open for 10 days in two months, but in 2023, it was open for only four days. During the entire dry season from December to April, the total operating time was only 32 days in 2023.

The lack of water has led to severe pollution, he said.

"The declining flow has crippled irrigation systems, caused severe pollution during the dry season, and turned Hanoi's western rivers into dead waterways," Thanh said.

Since 2010, the Ministry of Agriculture and Rural Development (now the Ministry of Agriculture and Environment) and Hanoi have launched several irrigation projects. However, they have failed to meet the requirements of management, operation, and long-term planning.

According to expert Nguyen Truong Duy of the Vietnam Association for Large Dams and Water Resources Development, the Tich River Water Replenishment Project was approved in 2010 to divert water from the Da River to irrigate 16,000 hectares. The first phase of construction began in 2011 and is almost complete.

Meanwhile, the Day River Restoration Project was designed to take water from the Red River at a rate of 36 m3/s during the dry season and 70 m3/s during the flood season. Completed in 2008, the project was designed to support downstream water supply, environmental restoration, and inland water transportation.

However, due to the low water level of the Red River, there is no water flowing into the two rivers, he said.

The main problem is that the water intake facilities are unable to take in water, and the wastewater is left untreated before being discharged into irrigation systems, causing severe pollution in several rivers and irrigation networks, he added.

West Hanoi also suffers from frequent flooding, especially in urban districts such as Bac Tu Liem and Nam Tu Liem, and rural areas such as Nam Phuong Tien and Hoang Van Thu communes in Chuong My District.

Severe flooding on the Day and Bui rivers has hampered drainage and disrupted people's lives, as sediment accumulation and narrowing riverbeds have made it difficult to drain water, Duy added.