Water quality in Ho Chi Minh City's Saigon and Dong Nai rivers declines again

After a period of improvement from 2021 to 2023, the water quality of the Saigon and Dong Nai rivers in Ho Chi Minh City is showing a downward trend again. The city's recently approved plan for managing surface water quality from 2026 to 2030 reveals a concerning picture, with key pollution indicators exceeding national technical standards.

Monitoring results indicate that while the overall water quality in the main rivers remained at average to very good levels between 2021 and 2025, a decline has been observed in the last two years. Specifically, on the Saigon River, the Water Quality Index (WQI) ranged from 57 to 93. However, from 2024 to 2025, this trend reversed, with a noticeable decrease in quality from upstream to downstream.

Pollution levels are particularly alarming in the canals that flow into the Saigon River. Here, the WQI fluctuates between 25 and 84, ranging from poor to good. Despite improvements in 2021-2022, quality decreased again from 2023 to 2025, showing little change compared to the 2016-2020 period. Some monitoring points recorded ammonia levels up to 87.8 times the standard and Chemical Oxygen Demand (COD) exceeding limits by 12.3 times, highlighting the immense pressure from domestic wastewater and urban sources.

The Dong Nai River, a vital water source for the southeastern region, is experiencing a similar decline. While its WQI is generally between 74 and 98 (average to very good), water quality improved from 2021 to 2023 but has since decreased. Ammonia levels have exceeded standards by 1.2 to 1.7 times, and COD levels have also surpassed limits in certain areas. Despite these challenges, some water bodies, like the Be River, maintain good to very good quality.