OVERALL river water quality in Malaysia saw a dip in 2025 as the number of polluted rivers increased slightly, says the Natural Resources and Environment Sustainability Ministry.
The ministry revealed that the number of rivers categorised as “clean” dropped to 468 at the end of 2025, a decline from the 486 recorded at the end of 2024, where 672 rivers were monitored.
Worryingly, the number of rivers with Class III or “moderate” water quality increased from 161 (24%) in 2024 to 171 (25%) in 2025.
The number of rivers deemed “slightly polluted” (Class IV) also rose to 33 (5%) compared to 25 (4%) in 2024.
However, no Class V (polluted) rivers were recorded in 2025.
“The sectors contributing to the deterioration of river water quality are not limited to the industrial sector alone.
“Other sectors such as livestock farming, agriculture, urban development, mining and commercial activities that either lack effluent treatment systems or have inadequate sewage treatment have also had an impact.
“Small-scale activities such as untreated wastewater discharge from wet markets, restaurants or food outlets, laundrettes and car wash centres have also contributed to river pollution,” the ministry said in a parliamentary written reply dated Monday.
The ministry added that it has begun taking both immediate and long-term measures to counter this worrying trend of river pollution.
This includes strengthening environmental legislation and enforcement and expanding its early warning pollution and quality monitoring systems.
It said it is also reviewing regulations for water pollution control and water quality standards as a long-term strategy.
The ministry was responding to a question from Datuk Seri Sh Mohmed Puzi Sh Ali (BN-Pekan), who wanted to know the number of polluted rivers across the country currently and the steps taken to resolve the issue.
