CMDA Project Components

Component 1:

Component 2:

Component 3:

Component 4:

Component 5:

This methodology proceeds from a Transboundary Diagnostic Analysis (TDA) to a Strategic Action Programme (SAP). The TDA provides the joint scientific and policy diagnosis of priority issues, while the SAP sets out ministerially endorsed solutions. Complementary components on cooperation, policy reform, and capacity building ensure that these processes are embedded in durable governance frameworks.

Project Area and Geology

The Cambodia–Mekong River Delta Aquifer system extends beneath Cambodia’s Mekong floodplain and the delta in southern Viet Nam.

The aquifer consists of Quaternary alluvial deposits and deeper Tertiary sedimentary formations, which together act as major transboundary groundwater reservoirs.
It supports domestic water supply for millions of people, irrigated agriculture in one of the world’s most productive deltas, and wetlands of international significance.
Groundwater is particularly critical in rural Cambodia, where piped supply coverage remains limited and dependence on wells is high.

Main Issues and Pressures

Over-abstraction and groundwater mining: Viet Nam’s delta provinces pump an estimated 2.5–3 million cubic meter/day, exceeding recharge in many locations. Cambodia’s abstraction is lower in volume but often unmanaged, with little licensing or control.
Land subsidence: Linked to groundwater extraction in the delta, with rates of 2–4 cm per year recorded in urban and peri-urban areas. This exacerbates flood risk and damages infrastructure.
Saline intrusion: Accelerated by reduced river flows, sea level rise, and declining groundwater levels. Salinity now penetrates tens of kilometers inland in the dry season.
Water quality degradation: Arsenic and iron contamination in shallow aquifers, especially in Cambodia, pose risks to drinking water safety. Agricultural and industrial pollution add further pressure.
Data and monitoring gaps: Viet Nam has several hundred observation wells, while Cambodia operates fewer than 20, limiting its ability to track groundwater levels or quality.
Institutional asymmetry: Viet Nam’s Department of Water Resources Management maintains structured groundwater management policies, while Cambodia’s frameworks remain at an earlier stage of development, creating challenges for harmonization.

These issues underscore the importance of a joint, science-based diagnostic and cooperative management framework.

Further Resources on Methodology and Tools