All eyes this week are on the Mekong, the mighty river that is the lifeblood of Southeast Asia.

As prime ministers, diplomats, and business and finance leaders gather in Vientiane for the fourth Mekong River Commission for Sustainable Development (MRC) Summit, there is a critical need to move the focus of discussions from its water to what flows beneath the surface. Not doing so will result in more decisions that fail to consider the biggest threat to the future of the Mekong Delta: the massive reduction of sand flowing down the river.

With an average elevation of less than a meter above sea level, the Mekong Delta was already one of the most vulnerable places on Earth to climate change, but the loss of mud and sand is drastically undermining the stability and resilience of the delta – increasing the threat posed by ever-worsening floods, droughts and storms as well as sea-level rise.

But the reduction of sediment is also causing more immediate problems, contributing to a drastic drop in the water table and sucking salt water further inland – risking one of the world’s most productive rice bowls and the livelihoods of millions of people.

Hydropower dams and unsustainable sand mining are responsible for this disastrous trend. It is essential to reverse these losses and ensure sufficient sediment flow in the river. This is what preserves the delta, dynamically replenishing land with new sediment to keep it above the rising seas and sustaining the offshore sand banks that protect the coastline and mangrove forests from the increasingly aggressive waves. 

The delta has already lost more than two-thirds of its natural sediment load, and leaving the situation would leave it with less than 3% by 2040. But this is just part of the story, only considering the sediment that is held suspended within the water, which is easier to monitor. There are no reliable data on how much sand is left just above the riverbed, which can take decades to travel the length of the river.

We now know how much sand flows 20 meters below the channels of the delta, with the completion of the world’s first-ever delta-wide “sand budget.” The results for 2022, though they still need to be peer-reviewed and validated, are alarming.

Most significant is that if current rates of sand extraction continue, stocks of exploitable sand in the Mekong will be exhausted within 10 years, undermining development that depends on sand and the very existence of the delta.

This new geotechnical tool operated by the Vietnam National Disasters and Dikes Management Authority within the Ministry of Agriculture and Rural Development, and funded by the German government’s International Climate Initiative, provides an excellent example of what can be achieved when different stakeholders work together.

The impacts of sand mining in the Mekong are also already being felt further upstream in Cambodia, Laos and Thailand. Riverbed incision caused by sand mining is eroding riverbanks, reducing the availability of water for agriculture and impacting productive wild fisheries, nature, and globally important textile and electronics supply chains.

These countries also need to have sand budgets and ensure enough sand remains in the Mekong. If not, Vietnam’s efforts will be in vain.

Collaboration needed

Just as the problem is basin-wide, so is the solution, as it can only be tackled through inter-state collaboration and collective action.

Sand flows through the Mekong from sources to sea and is therefore a valuable shared resource among the riparian countries. This makes it a transboundary river-governance issue – and one that should be just as central to the mandate of the MRC as water flow, also requiring a specific procedure for fine sediment.

The fourth MRC Summit has emphasized that there is legal basis for cooperation among countries and that the commission is the platform for dialogue and the resolution of issues as well as joint proactive basin planning. These are steps in the right direction that need to be followed through, and in that, reversing the negative impacts of sand mining on the Mekong River and to people in riparian communities must be a priority.  

The follow-through from the summit must take the path to sustainability. Critically, leaders need to take a close look at sand and value it not just as an essentially free raw material for construction but as an asset that provides priceless benefits to rivers and coasts, communities and cities, people and nature.

They need the knowledge and tools that support decision-making on where sand is most needed: in buildings, in landfills or in the river.

They need to know what else is possible to meet demand: alternative materials, manufactured sand, recycling and extracting sand from other, more sustainable, sources.

This must all be considered within the bigger picture – that keeping sand in the Mekong may well be the region’s most cost-effective climate adaptation strategy, a nature-positive way to build resilience.

What is crystal clear is that the current situation must not prevail or we will be watching the Mekong Delta sink below the waves. The delta needs both mud and sand in tandem.

Because the specific role of sand was not understood and valued, the resilience and long-term survival of the Mekong has been sacrificed for short-term gain. We can halt unsustainable sand extraction and allow the Mekong to work for us.

We need to chart a new course toward inclusive, resilient and sustainable development, a course where decisions factor in the value of a healthy Mekong and the diverse benefits it provides to people and nature.