Raging water disrupted life in Thame village—home to some of Nepal’s famed Sherpas—when a glacial lake in the Everest region burst its banks in August last year. The outburst wreaked havoc, damaging homes, farms, a school and a hydropower plant that provided electricity to local villages.

Despite the extensive damage, thankfully, there were no fatalities due to the quick thinking of locals, and the flood that arrived in the middle of the day allowed everyone to evacuate safely. With glacial lake outburst floods projected to happen more often in the Hindu Kush Himalayas, systematic risk reduction measures are necessary.

The Hindu Kush Himalayan region holds the world’s largest ice reserves outside the polar regions. It extends 3,500 kilometres over Afghanistan, Bangladesh, Bhutan, the People’s Republic of China, India, Myanmar, Nepal and Pakistan. Meltwater from glaciers provides fresh water for drinking, irrigation for agriculture, hydropower and water-intensive industries. But the Hindu Kush Himalayan glaciers melted 65 percent faster in 2011 to 2020 than the decade before, according to the International Centre for Integrated Mountain Development (ICIMOD). The occurrence of glacial lake outburst floods is now projected to triple by the end of the century. This threatens many of the 240 million people living in the mountains and 1.65 billion downstream.

Glacial lake outburst floods begin with a catastrophic wave that causes extreme dynamic impact, erosion, inundation and sediment burial that immediately endangers infrastructure, farmlands and lives. The damage then leads to longer term impacts like property damage from unstable ground and slow-moving landslides, new seasonal flooding from changes in river channels and loss of livelihoods.

We need to approach development differently to minimise the impacts of these cascading hazards on people and infrastructure. With support from Germany and Switzerland, which face similar challenges with unprecedented glacial melt in the Alps and downstream, the Asian Development Bank (ADB) is helping Bhutan and Nepal develop cost-effective adaptation solutions—such as establishing climate-resilient infrastructure and early warning systems—that could be replicated across the Hindu Kush Himalaya region with the right government policies and a conducive enabling environment for adaptation.

There are three key steps governments can take to minimise the risk.

First, a better understanding of multi-hazard risks is needed to support risk reduction decisions. This entails compiling and analysing the existing information on topography, hazards and locations of infrastructure and populations from maps, satellite imagery and inventories. This information, combined with local knowledge, needs to be tailored to support specific risk reduction decisions.

If applied well, government officials, investors and other stakeholders should be able to use a web-based platform that identifies zones of relative safety and danger from mountain hazards to support land use decisions. Information about hazard frequency and intensity provided in that platform, along with building and infrastructure design standards, would then be used to support design and rehabilitation decisions that promote resilience.

Second, risk reduction measures need to be cost-effective. Risk reduction options include: Building new infrastructure and retrofitting existing infrastructure to be resilient to mountain hazards; implementing a risk-informed land use plan; or establishing early warning and evacuation systems to save lives. When faced with a problem, the initial impulse is often to try to stop it at its source: For example, stabilising the landslide or draining the glacial lake. This is feasible in some cases, but impractical and too expensive in the Hindu Kush Himalaya region overall, given the geology, fragile topography, scale and number of hazards.

Many countries also have limited financial, material and human capacity resources, which exacerbates the challenge.

Therefore, ADB is developing tools to demonstrate the financial benefits and cost-effectiveness of risk management measures—and working with governments and the private sector to embed these tools in their decision-making.

Third, a regional perspective is critical. Glaciers in the Hindu Kush Himalayas feed 10 major rivers in Asia. This means risks from glacial melt impacts are transboundary. Countries will benefit from sharing information to help them prepare against potential flooding and related hazards. Sharing lessons learned from past disasters, as well as effective risk reduction practices and financing solutions that have been tried and tested, can help each country make better investment and policy decisions.

In all cases, it’s important to leverage local knowledge and actively involve the affected communities. As the Thame glacial lake flooding incident demonstrated, local knowledge is vital to saving lives in the face of impending disasters.

With accelerated glacial melt affecting nearly 2 billion people in the Hindu Kush Himalayas, governments, development institutions and the private sector must invest more in building resilience in both mountainous and downstream areas. We must mobilise concessional financing while developing new sources of financing such as carbon and capital markets, blended finance and risk transfer solutions.

Of course, there are limits to the prevention of losses through adaptation and more needs to be done to reduce carbon dioxide, methane and other emissions. If global temperatures rise by 3 degrees Celsius, up to 75 percent of glaciers in parts of the Himalayas will be lost throughout the century, which will ultimately threaten water availability and food security.

Countries need to be ambitious when they finalise their Nationally Determined Contributions this year, the International Year of Glaciers’ Preservation, to slow glacial retreat—and avoid further increasing the hazards that much of Asia is already facing.

Emily Mark, a Senior Geological Engineer at BGC Engineering, contributed to this article.