Drinking Water Quality

Safe drinking water is vital to your health and to the sustainable development of Hong Kong. Here you can have an overview of the work of the Government in providing high quality drinking water for Hong Kong and the measures adopted to safeguard water quality.

Sources of Drinking Water

Without natural lakes, large rivers or underground water, Hong Kong has been facing the challenges of securing a stable and adequate supply of water to meet its development needs. Over the years, the Government has developed an extensive rainwater collection and storage system. Now, about one third of Hong Kong’s land has been designated as water gathering grounds for collection and storage of rainwater. Nevertheless, the local yield is inadequate to meet the fresh water demand in Hong Kong. Due to unstable annual rainfall, the local yield collected each year fluctuates significantly.

To address with the challenges of inadequate and unreliable local yield, the Government has been importing Dongjiang (DJ) water since 1965 to meet local water demand. Currently, around 70-80% of Hong Kong’s fresh water comes from DJ while the remaining 20-30% comes from local catchments. To enhance the resilience of Hong Kong's drinking supply, the first stage of Tseung Kwan O Desalination Plant, which has commissioned in late December 2023, can provide Hong Kong up to about 5% of the drinking water supply that is unaffected by climate change.

Water Treatment and Quality Monitoring

There are currently 20 water treatment works and 1 desalination plant in Hong Kong which supply strictly treated drinking water to you. Hong Kong is one of the cities in the world that enjoys the safest drinking water. The Water Supplies Department has developed an integrated Drinking Water Quality Management System which includes a comprehensive programme to monitor water quality from sources to your taps and ensure that the drinking water quality complies with the Hong Kong Drinking Water Standards (HKDWS).

You Can Play a Part to Safeguard Water Safety

The Water Supplies Department is committed to providing a reliable and adequate supply of high quality drinking water but water quality may be affected by various factors inherent to a building’s internal plumbing system. The Water Supplies Department therefore encourages building owners and property management agents to join the Quality Water Supply Scheme for Buildings – Fresh Water (Management System) to safeguard the quality of drinking water at their properties by devising and implementing water safety plans for buildings which involves identifying potential contamination risks in internal plumbing systems and formulating corresponding control measures.