Nghe An: Water hyacinths 'kill' rivers.

At the Cau Ba River section flowing through Dien Thai commune (Dien Chau district),water hyacinthWater hyacinths completely cover the river surface, yet no one seems to be removing them or dredging the riverbed. Some residents in Hamlet 8, Dien Thai Commune, said: "Water hyacinths are covering the entire river surface; fish and shrimp can't survive, and boats can't move on the river. Our livelihoods are gradually disappearing because of this water hyacinth."

In recent years, water hyacinths have turned this river into a "dead river," causing stagnant water that turns black and emits a foul odor. In addition, garbage, plastic bags, and animal carcasses thrown into the river have caused severe pollution for residents living on both banks. What's concerning is that over the years, the Dien Thai commune authorities have not shown sufficient concern or mobilized the necessary personnel to remove the water hyacinths and clear the canal.

Water hyacinths completely cover the surface of the Cau Ba River section passing through Dien Thai commune, Dien Chau district, but for a long time, the local authorities have not paid attention to mobilizing manpower to remove them and clear the riverbed. Photo: Van Truong

Mr. Le The Hieu, Head of the Agriculture and Rural Development Department of Dien Chau district, said: The districtDien ChauCurrently, many rivers and canals are covered with water hyacinth, including Nha Le Canal, Vach Nam Canal, Do Lien Canal, Cau Ba River, etc. To address this situation, Dien Chau district annually provides local authorities with 300-400 million VND to clear the water hyacinth.

The money was mainly used by the communes to rent excavators to clear the water hyacinths, while the communes also collaborated with youth groups, women's associations, etc., to manually clear the hyacinths.

Right from the beginning of this year's rainy season, Dien Chau district has focused on mobilizing forces to dredge over 30,000 cubic meters of mud and water hyacinth in the communes of Dien Lien, Dien Doai, Dien Hoang, etc.

Completely eradicating water hyacinth is very difficult because it reproduces rapidly, while the number of manual laborers available to remove it is limited…

Water hyacinths cover the surface of the drainage canal in Hop Thanh commune, Yen Thanh district. Photo: Van Truong.

In Yen Thanh district, the situation is also worsening with the main drainage systems being completely covered in water hyacinth. It is easy to see large drainage channels such as the Bung River, Han River, and Roc Canh canals in Nhan Thanh commune, Yen Thanh district, along with many smaller canals, being "invaded" by water hyacinth.

Mr. Nguyen Si Tung, Chairman of the People's Committee of Nhan Thanh commune, said: During the rainy season, water hyacinth clogs most of the drainage system and river branches over 20 km long, slowing down water drainage and causing localized flooding in riverside hamlets, submerging many summer-autumn rice fields…

Faced with this situation, right from the beginning of the rainy season, Nhan Thanh commune mobilized over 4,000 local laborers to organize a campaign to remove water hyacinth; to date, over 80,000 m2 have been removed. The difficulty in removing the water hyacinth is due to the deep and wide muddy river, making it impossible for excavators to enter, so the water hyacinth has to be removed mainly by hand.

Dredging canals in Nhan Thanh commune, Yen Thanh district. Photo: Van Truong.

Mr. Le Van Hong, Head of the Agriculture and Rural Development Department of Yen Thanh District, shared: "The drainage system of Yen Thanh, including the Vach Nam, Vach Bac, Bau Chen, Bien Hoa, Trung-Long canals, etc., is currently mostly covered with water hyacinth. Since the beginning of July 2021, the Yen Thanh District People's Committee has directed communes to mobilize forces to remove the water hyacinth, and the district has allocated over 300 million VND from its budget to support key communes in this effort."

The Vu Giang drainage canal system, over 12 km long, drains floodwaters for the communes of Cong Thanh, My Thanh, Dai Thanh, Lien Thanh, and Khanh Thanh. Currently, the communes along the river have removed over 300,000 m2 of water hyacinth.

Dredging water hyacinth and silt to clear the Vach Bac drainage canal section in Do Thanh commune, Yen Thanh district. Photo: Van Truong

Surveys show that Nghe An currently has many rivers and key drainage canals being severely affected by water hyacinth, causing numerous problems. According to experts, a solution to mitigate the damage caused by water hyacinth could be to use it to produce biogas and organic fertilizer (compost): Water hyacinth, also known as water lettuce, is a biological product with a large biomass.

In some places, water hyacinth is used as a raw material or mixed with livestock waste for biogas digester technology to produce products for household use, saving on fuel costs, etc.