Malaysia
Last Updated : 22 April 2025.
Malaysia’s weather is characterized by two monsoon regimes – the Southwest Monsoon from late May to September, and the Northeast Monsoon from November to March. The Northeast Monsoon brings heavy rainfall, particularly to the east coast states of peninsular Malaysia and western Sarawak, whereas the Southwest Monsoon normally signifies relatively drier weather.
State of water environment
Malaysia is a rich water resource country thanks to its high rainfall. In 2022, the highest annual rainfall recorded to date, 6,172.8 mm, was recorded at Mulu station, 807.0 mm higher than in 2021, and the lowest, 1,943.0 mm, was recorded at Sitiawan station (DOSM 2023). In terms of volume, Malaysia’s annual rainfall equates to 972.8 billion m3. Of this, 495.71 billion m3 is surface runoff, 64 billion m3 goes to groundwater and the remainder returns to the atmosphere through evapotranspiration (ASM 2014). Malaysia’s weather is characterized by two monsoon regimes – the Southwest Monsoon from late May to September, and the Northeast Monsoon from November to March. The Northeast Monsoon brings heavy rainfall, particularly to the east coast states of peninsular Malaysia and western Sarawak, whereas the Southwest Monsoon normally signifies relatively drier weather (MoSTI 2010). Malaysia depends heavily on surface water – mainly rivers, lakes, wetlands and reservoirs – for water supply, which presently constitutes 98% of total water supply for domestic, industrial and agricultural use. The remaining 2% comes from groundwater. About 80% of the water withdrawn from river systems is used for irrigation. Percentages of water withdrawn from surface water sources for domestic and industrial uses are expected to rise in the future. Potable water supply extends mostly throughout the country except in a few isolated spots, where physical or geographical factors make it too challenging, for which wells or rural water supply scheme systems are provided.
According to ASM (2014), current water consumption is about 12.5 billion m3/year, or less than 3% of the available runoff. This is expected to increase by about 5% annually, to around 30.4 billion m3/year by 2020, 60.8 billion m3/year by 2040, and 121.6 billion m3/year by 2060 due to the rapidly rising population and industrial growth. Irrigation will continue to be the largest water user, but its share is expected to be outpaced by domestic and industrial consumption.
Please read: The Outlook 2024 Malaysia
Legal framework
Institutional Arrangement
Key institutions for environmental protection, surface water resources and wastewater management
| National level | Roles of subnational government |
| Ministry of Natural Resources and Environmental Sustainability (NRES): Environmental protection, including water quality management Ministry of Energy Transition and Water Transformation (PETRA): Water resource management, irrigation and drainage, sewerage service and water supply Ministry of Health: Regulation of drinking water quality National Water Commission: Water supply and sewerage service |
Local governments are involved in water resources planning, development and enforcement based on local authority by-laws. |