©FAO/Proyuth Ly

To celebrate this year’s World Water Day, dedicated to groundwater, FAO Representation in Cambodia is excited to unveil a new Global Environment Facility (GEF) International Waters project, spotlighting transboundary Cambodia-Mekong River Delta Aquifer, which is soon to be approved and ready for implementation by the end of this year.

The lower section of the Mekong River Basin is underlain by a major transboundary aquifer system shared by Cambodia and Viet Nam. This transboundary aquifer system (TBA) connects two ecosystems of global environmental significance and socio-economic importance: i) the Tonle Sap area and the ii) the Mekong Delta, including some major urban areas such as Phnom Penh and Ho Chi Minh city.

The whole area is approximately 200 000 km2, with about 63 per cent lying within Cambodian territory. The Tonle Sap, the largest lake in the peninsular Indochina, is hydraulically connected to the Mekong River, and serves as a natural regulating reservoir ensuring adequate groundwater recharge to the aquifer.

Groundwater strongly supports the agricultural sector in Cambodia, which accounts for about 24.4 per cent of the country’s GDP and employing approximately 37 percent of its labour force. For these reasons, the aquifer is heavily exploited for irrigation and water supply.

The groundwater resources in this TBA have a considerable impact on human livelihoods and socio-economic development.

The integrity of ecosystem services is critical both in terms of biodiversity and of the sustainability of a range of natural resources and products available to both urban and rural populations. The effects of surface and groundwater interactions nourish large tracts of forests and wetlands, which produce building materials, medicines and food, and provide habitats to thousands of species of plants and animals.

Naturally, groundwater interacts with areas of low-lying land where permanent wetlands tend to develop. These wetlands provide habitat for fish breeding, buffer flood events by absorbing huge quantities of excess water and offer natural water cleansing functions. In addition, groundwater sustains wetlands during the dry season: when groundwater levels drop below the historic norms, wetlands can dry out.

Unfortunately, there are a wide array of challenges facing sustainability of the groundwater system and its quality, ranging from overexploitation of the groundwater resource to support economic activity, occurrence of arsenic, deforestation, climate change and upstream hydropower development.

Responding to these challenges and the request by the governments of Cambodia and Viet Nam, the GEF International Waters Fund has confirmed a USD 15 million funding and allowed FAO to develop the project “Enhancing sustainability of the Transboundary Cambodia - Mekong River Delta Aquifer” under GEF-7. The project seeks to strengthen the environmental sustainability and water security in the Lower Mekong Basin by focusing, for the first time, on improved governance and sustainable utilization of the Cambodia-Mekong River Delta Transboundary Aquifer.

Read further about this project here.