According to VNMC, the Mekong Delta provinces are about to welcome another wave of deep saltwater intrusion. The reason is that the reservoirs on the Lan Thuong River (upstream of the Mekong River flowing through China - PV) are at about 50% of the total useful capacity. Among them, there are large reservoirs such as Noa Trac Do lake containing about 40% of its capacity (4,4 billion m3) and reservoirs in the lower Mekong basin are also holding at about 55%.
The Mekong Delta is about to welcome a new wave of saltwater intrusion in the next few days
With the above conditions, along with the decreasing flow trend on the main stream of the Mekong River. The flow through Kratie station in March tends to decrease and the amount of water stored in Tonle Sap (Cambodia) is also low, currently only 3 billion m3. Therefore, the ability to contribute to the mainstream of the Mekong River is very limited.
The average daily flow to the Mekong Delta through Tan Chau and Chau Doc stations in March will continue to decrease from 3 m3/s down about 3.400 m3/s, at a level similar to the average of many years but lower than the same period in 2023. The total flow in March through these two stations is likely to be about 3 - 2023% lower than the same period in 25.
There is little water coming from the upstream, salinity penetrates deeply into the tributaries in the Mekong Delta in March. The 3‰ salinity line is the deepest on the three major tributaries (Hau River, Tien River and Vam Co Tay River) from 1 - 8km compared to the average of many years and 12 - 3.2023km deeper than saltwater intrusion in the same period in March 5. The 8‰ saline boundary is 4 - 6km deeper than the average for many years and 10 - 2023km deeper than the same period in 4.
From now until the end of March, there will still be a deep saltwater intrusion from March 3 - 20 (high tide in the middle of the second lunar month). Therefore, areas frequently affected by salinity need to closely follow salinity monitoring information and saltwater intrusion forecast bulletins to operate appropriate salinity prevention works to take advantage of storing water into the canal system. Because water sources will become increasingly scarce during the dry season, localities need to have plans to take water alternately from rivers and canals to avoid local depletion, leading to deeper saltwater intrusion.
Hydroelectric dams cause irregular flow of the Mekong River
The recent weekly newsletter of MDM (Mekong River Hydropower Dam Operation Monitoring Project) details: Drought in China and northern Laos during the 2023 rainy season continues to cause water flow The natural level of the Mekong River is lower than normal in the dry season of 2024. The impact of the dam is causing the water level across the Mekong River to fluctuate abnormally according to the closure and release of water. The common trend from the beginning of the dry season until now is that the amount of water released from upstream hydroelectric dams on the main stream of the Mekong River is very limited. However, at some times the amount of water released is higher than normal, causing the river water to rise in some places. Specifically, last February, the amount of water in Stung Treng (Cambodia) increased twice compared to normal years.
The general trend is that river water levels throughout the Mekong River basin are generally lower than normal during the same period. At Tonle Sap, the water level is about 30cm lower than normal compared to the same period in many years.
VNMC warns nplaces with severe saltwater intrusion
Long An Province: Tan Tru, Ben Luc, Thu Thua, Can Duoc, Can Giuoc, Thanh Hoa and City. Tan An
Tien Giang Province: Go Cong Dong, Go Cong Tay, Go Cong Town, Cho Gao, Tan Phu Dong
Ben Tre Province: Ba Tri, Binh Dai
Tra Vinh province: Cau Ngang, Tra Cu, Tieu Can, Chau Thanh
Soc Trang Province: My Xuyen, Long Phu, Thanh Tri, Nga Nam
Bac Lieu Province: Vinh Loi, Hoa Binh, Phuoc Long
Kien Giang Province: Vinh Thuan, An Bien, Hon Dat, Giang Thanh
Hau Giang province: Long My, Vi Thuy, Nga Bay, Vi Thanh.
