Agriculture feel the heat: [2] Preserving fresh water amidst dry season

Watching water levels hour by hour at key salinity control gateway

In early April, the water surface at An Ha sluice gate (Binh Loi Commune) shimmered under the intense sun. This is one of the most critical water control points at the western gateway of Ho Chi Minh City, determining the ability to retain freshwater for the entire Hoc Mon - northern Binh Chanh area. As temperatures continue to rise, the pressure on sluice operators has become greater than ever: even a slight miscalculation in the timing of gate operations could allow saline water to intrude deep into inland areas.

Bài liên quan

Agriculture feel the heat: [1] Thirsty crops and stressed livestock

Pressure is even greater this year as upstream water supplies have declined significantly. According to Mr. Tran Quang Hung, General Director of Southern Irrigation Exploitation One Member Co., Ltd., the water level of Dau Tieng Reservoir, a strategic water source for the entire Southeast region, is dropping during the peak of the heatwave.

“This could directly affect agricultural production and the capacity to push back salinity in downstream areas of Ho Chi Minh City. As the largest reservoir in the region sees reduced storage, every water discharge must be carefully calculated to both ensure irrigation and maintain flows to combat saline intrusion,” Mr. Hung said.

Over the past two months, the Southeast region has been warned that it is entering the peak of the 2026 dry season. According to the Southern Institute of Water Resources Planning, the Sai Gon River basin currently holds only about 65.2% of its designed capacity, 2.1% lower than the same period last year, requiring particularly cautious water regulation.

In the area along both sides of Provincial Road 10, around 16,000 hectares of agricultural land and 600 hectares of protective forest depend almost entirely on the ability of the irrigation system to retain freshwater. Each day, at An Ha sluice gate and many other key control points, technical staff must continuously measure salinity, monitor water levels, and calculate optimal operation timing.

Mr. Nguyen Hai Dang, Deputy Director of the Hoc Mon - Binh Chanh Irrigation Management Enterprise, said this year’s dry season arrived earlier and has been more severe than expected. “We are currently at the peak of the dry season. Our unit regularly inspects the entire system to ensure effective operation. At the same time, we are clearing channels, improving conveyance and storage capacity, and ensuring that freshwater is always available in the fields,” he noted.

Beyond An Ha, the entire Sai Gon River corridor across Hoc Mon and northern Binh Chanh is equipped with around 300 tidal control structures of various sizes within the dyke system, including 20 key salinity-control sluices with openings wider than 5 meters. Each structure is maintained daily to ensure operational capacity.

Mr. Nguyen Van Dam, Chairman of the Members’ Council of Ho Chi Minh City Irrigation Management and Service One Member Co., Ltd., emphasized: “We are inspecting all infrastructure to be ready for salinity control during the dry season, while strictly applying operational procedures to store water in the fields and ensure irrigation supply for areas along the Sai Gon River, Hoc Mon, and northern Binh Chanh.”

In this context, the Ho Chi Minh City People’s Committee has directed departments, sectors, and localities to implement synchronized solutions to combat drought, water shortages, and saline intrusion. This is no longer solely an irrigation issue but a matter directly linked to food security and the livelihoods of tens of thousands of farming households.

Water becomes the lifeline of the fields

While in the southwestern part of the city the challenge is to prevent salinity and retain freshwater, in northwestern areas such as Cu Chi, the priority is to ensure continuous water flow from the East Canal system - the primary water source for local agriculture.

At Binh Minh Koi Farm, an ornamental fish farm with over one hectare of water surface in Cu Chi, the ponds remain full despite weeks of prolonged heat. For farmers like Mr. Nguyen Ngoc Hai, water stability is a prerequisite.

“Whenever there is a plan to reduce water supply, the East Canal irrigation management board informs us in advance so that we can proactively store water or adjust production. Thanks to that, we are not caught off guard,” Mr. Hai shared.

Along the East Canal, hundreds of hectares of vegetable crops remain lush and green. In a bitter melon garden entering its peak growth stage in Thoi My Commune, Mr. Bui Van Loc checks each row of plants under nearly 36°C heat. He noted that crops require continuous watering during this season, but his family has not faced water shortages for many years.

“Water was already abundant during the winter-spring crop, and even into the summer-autumn season it remains stable like this, so farmers feel very reassured. Everyone has enough water for production - there is no shortage,” Mr. Loc said.

In 2026, the total irrigated agricultural area in Ho Chi Minh City is expected to exceed 80,000 hectares. Of this, more than 22,000 hectares for the winter-spring crop have been completed, while the summer-autumn crop is entering its peak period with around 25,000 hectares. As a result, pressure on water supply is increasing rapidly with each hot day.

Alongside this, technology is becoming a powerful support tool for the irrigation sector. According to Mr. Nguyen Van Dam, Ho Chi Minh City has deployed a SCADA system to manage operations, enabling real-time monitoring and water regulation. “The application of SCADA helps optimize water supply, ensuring adequate irrigation while maintaining reasonable storage throughout the dry season. The water level of Dau Tieng Reservoir is currently equivalent to or slightly lower than the same period, but it still has sufficient capacity to proactively support production,” Mr. Dam said.

Dau Tieng Reservoir is a particularly important irrigation work located upstream of the Sai Gon River, serving as a “strategic reservoir” for the entire Southeast region. It currently provides direct irrigation water for about 12,000 hectares of agricultural land in Ho Chi Minh City, while also helping to push back salinity and supply water for nearly 28,800 hectares along the Sai Gon River.

However, challenges remain. Forecasts from the Southern Regional Hydrometeorological Center indicate that April is still the peak of the dry season. Although some unseasonal rainfall may occur, it is insignificant compared to the high evaporation rates. This means that every cubic meter of stored water today is crucial for the upcoming summer-autumn crop.

Facing increasing risks of drought and saline intrusion during the peak of the 2026 dry season, Ho Chi Minh City is shifting its focus from “passive salinity control” to “proactive freshwater storage.” Under the direction of the city’s People’s Committee, the entire irrigation system is required to prioritize maximum water storage in fields, dredge canals to increase capacity, strictly operate salinity-control sluices, and coordinate water releases from Dau Tieng Reservoir to ensure irrigation for more than 80,000 hectares of agricultural land.