The October 11 flood in the Budhi Gandaki is a reminder that Nepal's river disasters can begin well above the riverbanks. Preliminary police reports suggest a landslide near Siringe Himal blocked a stream. Water accumulated behind the obstruction and was released when it breached. Alerts went out to communities downstream along the Trishuli and Narayani. Investigators still need to establish exactly what happened.
The reports bring Rasuwa back into view. On August 26, a slope collapse near Langtang Lirung sent rock, ice and debris into the Lhende Khola valley. The flood then travelled more than 100 kilometers through the Bhote Koshi and Trishuli river system, crossing the international border and damaging communities and infrastructure far from where it began. The government puts recovery and reconstruction needs at approximately US$4.78 billion, separate from the roughly US$2.7 billion in physical damage and economic losses. These figures describe different things and should not be confused. They also show how much Nepal, one of Asia's poorer countries, stands to spend recovering from a failure on a mountainside.
At the UN General Assembly, Prime Minister Balen Shah said Nepal's people should be able to "build their future instead of constantly rebuilding their past." The words captured a frustration many Nepalis know well. We build a road, bridge or public facility, lose it to a disaster, and spend scarce money replacing it. Other needs wait.
Budhi Gandaki and Rasuwa valley now puts a practical question before his government: what will be done differently when reconstruction begins?
First, the two disasters need separate explanations. Preliminary accounts of Budhi Gandaki point to a landslide blockage and breach. Langtang Lirung involved a rock–ice avalanche and a cascading debris flood. Neither should be casually described as a glacial lake outburst flood or a "Himalayan Tsunami". The distinction affects what we monitor and how we protect people downstream.
River gauges are necessary. But they tell us what is happening in the river, not everything that could happen above it. A newly obstructed stream or an unstable slope may need attention before rising water reaches a gauge. Looking only at the channel leaves part of the danger unexamined.
For a bridge, the assessment should include slopes and tributaries upstream. Could debris block the channel? Where would water collect? If the blockage failed, what would reach the bridge and the settlements beside it? Similar questions belong in the design of roads and hydropower projects.
Answering them may mean changing an alignment, raising a bridge or abandoning a site. Those decisions can be expensive and unpopular. But an assessment has little value if its findings are filed away while construction proceeds unchanged.
Global warming deserves serious attention here, without being used as a ready explanation for every disaster. Ice in fractured rock and frozen ground can help hold steep slopes together. Thawing can weaken them. Changes in glaciers can also affect slope stability. Researchers examining Langtang Lirung have considered these factors alongside geology, rainfall and earthquakes.
Rescue, shelter and restoring access are the immediate priorities. Permanent reconstruction requires more thought. Replacing a damaged structure in the same place without reviewing its exposure could leave it vulnerable to another upstream failure.
Local authorities need practical arrangements for such situations. Who investigates a reported blockage? Who warns downstream villages? Who can order an evacuation? Where should people go? These questions need answers, staff and funding before a flood, not hurried discussion while it is approaching.
Residents should help shape those arrangements. Their traditional knowledge of the terrain, streams and seasonal changes can inform monitoring and evacuation plans. They know which paths remain usable and who needs help. Warnings must reach people in language they understand, including those without reliable telephone coverage.
Langtang Lirung also highlights the need for cooperation across borders. Researchers have called for rapid downstream communication, shared data and coordinated warnings. The contacts and procedures must already be in place when an emergency begins.
Hydropower developers, road authorities and financiers have responsibilities too.
Upstream instability belongs in project appraisal. Melamchi should already have made us wary of treating the immediate construction site as the full extent of a project's exposure.
These concerns led me to originate and develop the International Center for Glaciers and Permafrost, or ICGP, and lead its Asian Development Bank, commissioned, concept-level study.
I envisaged a global institution bringing together glaciated countries, with a specific focus on glaciers and permafrost and adaptation at its core. It was never intended as a Nepal-only initiative or a substitute for national authorities and existing research institutions.
The center should strengthen specialized monitoring, risk assessment, adaptation national capacity, support cooperation across borders, and help countries secure funding for adaptation. It should not claim expertise over every landslide. Its contribution would be glacier and permafrost knowledge that governments can use in managing mountain hazards.
Budhi Gandaki and Rasuwa deserve careful investigations whose findings influence reconstruction. Balen's words at the UN will mean more if they guide decisions at home.
Before committing money to rebuilding downstream, Nepal must examine what could fail upstream. Otherwise, we may again spend tomorrow's development budget replacing yesterday's losses. We cannot afford that repeated expense.
Rajouria is a climate and diplomatic strategist working on climate resilience, glacier risk and international cooperation. He conceived and has advocated for the proposed International Center for Glaciers and Permafrost as a laser-focused international platform for science, adaptation, risk reduction and cooperation among glaciated countries.