A saltwater prevention sluice in the Cửu Long (Mekong) Delta province of Bến Tre. – VNA/VNS Photo Công Trí

HCM CITY – Saltwater intrusion will affect about 40,000ha of fruits and 5,000ha of rice in the Cửu Long (Mekong) Delta this month, according to the Ministry of Agriculture and Rural Development’s Irrigation Department.

The fruit areas are in Tiền Giang, Bến Tre, Vĩnh Long and Sóc Trăng provinces, while the rice areas are in Trà Vinh Province.

The level of saltwater intrusion in the ongoing 2020 - 21 dry season is higher than average, but lower than the dry season in 2015 and 2020.

Saltwater intrusion from sea through river mouths began occurring at the delta’s main rivers on January 24, nearly one month earlier than the average of many years.

Before the beginning of the 2020 – 21 dry season, local authorities in the delta took various measures to protect agricultural production and households from saltwater intrusion.

The measures include building and upgrading irrigation works, dredging irrigation canals, and restructuring crop cultivating schedules.

Seawater with a salinity rate of four grammes per litre is expected to enter 50 – 85 kilometres deep into the mouths of the delta’s main rivers this month.

At the Hàm Luông River, for instance, saltwater intrusion will enter 65 - 70 kilometres deep into the river mouth.

Most crops can only tolerate a salinity rate of up to one gramme per litre.

Saltwater intrusion will gradually fall in April and May, according to the Irrigation Department.

The high level of saltwater occurs during high tides when seawater rises and enters deep into river mouths.

In previous high tides this year, saltwater entered deep into river mouths on January 10 – 14, January 24 – 30, February 12 – 16 and February 24 – March 2.

The delta had heavy rains in January and February, but local farmers stored irrigation water in their orchard ditches, so the orchards and daily-use water have not been affected.

Farmers in the delta, the country’s rice granary, have harvested 400,000ha of 1.51 million hectares of the ongoing 2020 - 21 winter - spring rice. The winter - spring rice was sown earlier than normal to avoid a shortage of irrigation water at the end of the crop.

To secure irrigation water for the upcoming summer – autumn rice crop, the Irrigation Department has told localities to only grow crops in areas that have enough irrigation water. If they do not have enough, farmers should only start growing a new rice crop when the rainy season starts, it said.  – VNS