Cambodia has ample supply of water, mainly from the Mekong River, Tonle Sap River, Bassac River and other tributaries . Rivers and streams, lakes, aquifers and marine water are important sources for national economic development in many sectors, such as agriculture, manufacturing and small-scale industries, hydropower, navigation, tourism, environmental protection and daily life . Based on per capita water availability, Cambodia is not a water stressed country, but challenges exist related to water quality and stability of water supply in both the wet season and dry season .
In general, surface water in Cambodia meets the national ambient water quality standards, i.e., it is not polluted. However, water quality has been under threat in some areas, especially during the dry season due to the inflow of untreated effluents into public water bodies from urban activities, agricultural run-off, navigation, etc. .
Achieving the Sustainable Development Goal 6 (SDG6) on clean water supply and sanitation presents a huge challenge for Cambodia. As of 2017, access to safely managed water supply in the country was only 26%, and access to basic sanitation was 59%. Of the total number of people who have access to piped water services in Cambodia, approximately 50% of them get their clean water from Private Water Operators (PWOs) through small-scale piped water supply systems .
The disparities between urban and rural areas are significant: Only around 20% of rural residents can access clean water, while in population centres the rate is 70% . Although Cambodia has one of the fastest growing economies in Asia, access to affordable financing for water and sanitation remains a barrier for families to secure water connections and toilets for their homes .
Cambodia’s water resources are facing increasing pressure due to rapid population growth, urbanization, industrialization, climate change, agriculture, and economic development.
For instance, water for agricultural irrigation is directly pumped at source (from rivers, lakes and the ground). Given the risks of depletion, the Ministry of Water Resources and Meteorology (MoWRAM) has adopted a precautionary approach to groundwater use, limiting its use to supplementary provision rather than to full irrigation in the dry season. While these approaches reflect best practice, they are however difficult to implement at a large scale. Besides irrigation, groundwater is also used by industries and, in many areas, it is the main source of domestic water supply. Even though relevant data are not available, negative impacts can be assumed if this extraction continues to increase in an uncontrolled way .
Water supply and wastewater treatment are becoming major concerns for the Cambodian authorities and development partners. Poor water quality partly stems from the rapid economic development of Cambodia but also reflects poor water quality management by the Government and industry. Cambodia’s population and corporations remain insufficiently aware of the need for efficient water use. The main reason for this is assumed to be the low cost of water, which is significantly cheaper than electricity, for example .
Groundwater quality is generally satisfactory, but high iron levels and salinity occur in some areas. In addition, leachates from agriculture and landfills affect water quality. Large hydropower projects on the Mekong and its tributaries are likely to have detrimental effects on access to water for downstream communities and countries when the water level is low .
Even though discharging untreated and low-quality treated wastewater carries environmental and health-related risks, it remains a common practice in Cambodia because the systems required to treat wastewater are insufficiently developed .
In addition, climate change will increase water management challenges; less rainfall is anticipated during the dry season and more during the wet season, with more extreme weather events and potentially worse seasonal water shortages and floods . The changes in rainfall and weather patterns have a significant impact on water resources and the hydrological system, causing seasonal instability of water supplies, as well as increasing water quality issues .
Key policies and governance approach
In Cambodia, several ministries deal with water-related management, including the Ministry of Environment (MoE), the Ministry of Water Resources and Metereology (MoWRAM) and the Ministry of Public Works and Transport, among others.
Several laws and regulations govern the water sector including, the Law on Environmental Protection and Natural Resource Management, Law on Water Resources and Management, Sub-decree on the Control of Water Pollution, Sub-decree on the Establishment and Management of the Special Economic Zone and Sub-decree on the Management of Drainage System and Wastewater Treatment System , .
The National Strategic Plan on Water and Rural Sanitation 2011-2025 helps guide actions and implementation plans to expand connections and supply of clean water, wells and ponds, distribution of filtration tanks and installation of storage tanks . It also formulates the target of 100% access to water supply, sanitation and hygiene across the country by 2025 . To achieve this, the Ministry of Rural Development has prepared the first National Action Plan for Rural Water Supply, Sanitation and Hygiene 2014-2018, the second National Action Plan for Rural Water Supply, Sanitation and Hygiene 2019-2023, along with the Ministry’s Rural Development Strategic Plan 2019-2023 with efforts and contributions of all stakeholders especially development partners at all levels .
The MoWRAM is responsible for overall management of water resources in Cambodia. The Ministry planned to develop the Strategy and Action Plan for Water Resource and Meteorology 2019-2023 to implement the NSDP 2019-2023, and has a total of 131 hydrological stations around the country, but only 59 are operational. Of these, 47 stations are installed along the Mekong River and 12 on key tributaries in Cambodia .
SUCCESSES AND REMAINING CHALLENGES
Cambodia has made substantial effort to improve water governance on quality and quantity. However, there are still many water pollution incidents. In addition, the monitoring and management of point source pollution (wastewater from industrial zones, special economic zone, business buildings) and non-point source pollution (agricultural runoff, aquaculture practices, and urban wastewater discharge) is still limited and not fully effective under the existing law and regulations.
Enforcement of regulations in Cambodia is urgently needed. Inadequate institutional and legal frameworks for urban wastewater treatment remain a challenge in the country . The water quality challenges mainly relate to industrial development, primarily close to the capital Phnom Penh. Although polluters have been asked to install wastewater treatment facilities to treat wastewater from their production, there have been several water pollution cases where industrial effluent violated the discharge standards stipulated in Sub-decree on the Control of Water Pollution.
Moreover, climate change and transboundary environmental problems have put more pressure on water protection in all main water resources and river basins. Therefore, planning and implementing sustainable management of surface water and groundwater and improved management of Cambodia’s watersheds, in the context of climate change, remains a major challenge.
Initiatives and Development Plans
In 2019, the Asian Development Bank (ADB) approved US$49 million in financing to help the Government achieve its 2025 goal of providing universal access to improved water supply and sanitation services in the country’s rural areas. The Third Rural Water Supply and Sanitation Services Sector Development Program will benefit more than 400,000 people by constructing or rehabilitating 2,500 rural water facilities in at least 400 villages across 10 Cambodian provinces. It will also support the construction of new toilets for individual households and construct public latrines at schools and health centres, as well as conducting hygiene and sanitation awareness campaigns .
In 2021, construction works began on the Bakheng Water Production Facilities, Cambodia's largest water treatment plant. The project financed by the European Investment Banks (EIB), the European Union, and France's Agence Francaise De Development (AFD) will allow an increase in water production capacity in Phnom Penh, Cambodia's capital and the largest city, by 65%, from current 600 000 m3/day to around 1 000 000 m3/day expected in 2024. The water treatment plant is expected to meet Phnom Penh's water demand and offer access to safe drinking water to the entire city by 2025. To accomplish this, the local water authority Phnom Penh Water Supply Authority (PPWSA) will expand its water supply network by 1600 km allowing more than 100,000 new homes and 25,000 new businesses to connect .
Goals and Ambitions
A specific goal of Cambodia’s SDGs is to “improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse”. This goal needs to be matched by improved monitoring and data collection.
- Funding for safe water supply production and network connections should be allocated widely throughout the country.
- The relevant projects of monitoring and assessment of water quality should be routinely conducted in some major water sources.
- Law enforcement on private sector and other polluters can be improved so that the discharge effluent will comply with national effluent standards, allowing Cambodia to maintain water quality effectively and efficiently.
- Introduce geographical information systems (GIS) for controlling and monitoring technical processes (e.g., in waterworks).
- Installation of water quality control equipment in the drinking water network.
- Equipment for carrying out leak detection.
- Frequency inverters for pumping stations to regulate output into the drinking water pipe network.
- Cleaning of pipe networks.
- Training on planning operational management capacities.
 World Bank (2020). [Online]. Available: https://www.worldbank.org/en/results/2020/07/22/partnering-for-impact---strengthening-institutions-to-bring-water-and-sanitation-services-to-cambodias-rural-areas.
 water.org. [Online]. Available: https://water.org/our-impact/where-we-work/cambodia/.
 General Directorate of Environmental Knowledge and information, Ministry of Environment (2021). The Fourth State of Environment Report.
 ADB (2019). [Online]. Available: https://www.adb.org/news/adb-help-cambodia-expand-access-water-supply-sanitation-services.
 EIB (2021). [Online]. Available: https://www.eib.org/en/press/news/safe-drinking-water-for-cambodia-s-phnom-pehn.