Nepal should tell the world that the climate crisis in the Himalayas is putting the country's largest and most expensive drinking water project at sustainability risk.

--BY RAJENDRA PRASAD ADHIKARI

Despite the failure of the Egypt climate conference to establish the necessary level and pace of emission reduction to achieve the 1.5-degree climate goal, or to develop a practical plan for Nationally Determined Contributions (NDCs) aimed at achieving net zero emissions, the COP-27 was successful in addressing the issue of loss and damage compensation.

Several islands and highland nations in the high-risk climate change impact zone are on the priority list of countries for loss and damage compensation. Nepal, which is sandwiched between the two industrial giants - India and China - using a vast amount of coal and fossil fuel for their economic growth, suffers significantly not only from the heat waves generated by the distant global partners but also from the persistent emission emitted by the next door neighbours.

Rapid depletion of glaciers from the Himalayan terrains, localised torrential rainfall of extreme scale, prolonged drought followed by forest fires in high altitude areas and physical destruction of infrastructures such as hydropower plants, highway networks, bridges as well sabotage of water delivery components of drinking water projects have been a routine occurrence beginning in the pre-monsoon season and intensifying through the post-monsoon time.

These extreme events are caused by an erratic hydrological cycle resulting from ocean moisture circulation, which is affected by heat waves, rising to higher altitudes.

In 2021, farmers in western Nepal were unable to harvest their paddy crop due to unusual post-monsoon downpours, leading them to demand compensation for standing crop damage and loss, which they have yet to receive as promised by the government.

Internal and external migration has become the fate of mountain communities in Nepal when they lose breadwinners and farming terraces to landslides and erosion caused by rain-induced floods or glacier outburst floods. The devastation faced by the country's most expensive drinking water project at the Melamchi River, funded by the Asian Development Bank (ADB), is a prime example of the climate crisis that swept glacial moraine debris across the entire river valley and deposited it at the project's headworks.  

In the aftermath of the catastrophic event that struck the Melamchi Valley on June 9, 2021, numerous factfinding reports published by research wings of international organizations, including the World Bank, Asian Development Bank, and ICIMOD, concluded that the six-day long torrential rain, which resulted in a total rainfall of 200mm - approximately 170% higher than the average rainfall in the Melamchi Valley - triggered a series of land erosion and landslides along the long and narrow Himalayan valley. This is an example of the occurrence of multiple hazards, either simultaneously or with one hazard triggering others. The heatwave around the high snowline, where the headwaters of the Melamchi are located, caused rapid glacial snow depletion and torrential rainfall, thereby accelerating glacial moraine erosion.

The resulting debris flow, comprising of snow water, rain, and glacial moraine rock fragments, formed natural dams and subsequent breaches at several locations, washing away numerous villages, public and private infrastructure including suspension bridges, road bridges, and a large portion of agricultural terrace land, all the way down to the Melamchi tunnel intake. The destruction of the hydromechanical setup at the tunnel gate rendered the Melamchi water supply nonfunctional, converting perennial water delivery into a seasonal one.

The Melamchi project, which is considered a lifeline for the people of the Kathmandu Valley, supplies the daily demand of 170 million liters of drinking water per day through a 26 kilometer tunnel connecting the Melamchi Valley to Kathmandu. However, less than three months after the national pride project was inaugurated in March 2021, the water supply came to a halt. The Kathmandu Valley, home to 3.5 million people, suffers from a shortage of drinking water as the old water supply systems are unable to meet the needs of a growing population. The complex underground geological formations and the lack of snow-fed perennial water sources have left valley residents without sufficient ground and surface water. Tunnel supply from a snow-fed river in an adjoining district is the only viable and lasting solution for the people living in the valley, but the consistent and reliable supply has been jeopardized by the June 9, 2021 climate crisis.

Although the water supply to the Kathmandu Valley has been resumed through temporary arrangements, the impact of climate change, which began with heatwaves around the snowline a week before the devastating flood, has seriously damaged the watershed of the Melamchi River and its tributaries, with no signs of immediate recovery, putting stress on the aquatic ecosystem in the Himalayan river valley.

Since the Melamchi aquatic ecosystem is a part of a larger watershed that includes Himalayan peaks and glacial lakes at the top, heatwaves surrounding the snow peaks accelerate the smaller headwater flow from glaciers, thereby eroding the fragile watershed landscape on its way down. The entire water-oozing valley, with rampant erosion and debris deposition due to the monsoon devastation of last year, has altered the age-old pristine river health environment, where living plants, animals, and microorganisms can no longer perform water purification activities efficiently. Restoring a healthy river environment will require a higher cost and technical expertise in regenerating both biotic and abiotic interactions, a natural process responsible for producing high-quality drinking water.

The inability of the Melamchi project to provide reliable and year-round drinking water to the people of the Kathmandu Valley is a matter of serious concern not only for the government in meeting the basic needs of its citizens, but also as a failure on the part of the government to meet its obligations under the United Nations Sustainable Development Goals (SDGs).

The opening speech of the UN Secretary General, Antonio Guterres, at the COP-27, in which he defined the issue of climate impact loss and damage compensation as a yardstick for measuring the success of the Egypt conference, implies that wealthier nations responsible for emissions are causing rapid snow melting and depletion of water resources in the Himalayas, seriously depriving communities of their basic water needs.

Nepal, with a mere 0.056% share of carbon emissions - a small fraction compared to the global average - and with a carbon sequestering capacity due to its 45% forest cover, has been an active participant in the United Nations Framework Convention on Climate Change (UNFCCC) since 1994. The UN committee needs to assess the causes and effects of the damage on various natural resources in the Himalayas, both in the high and low mountains and in the flat plain of Tarai.

There is an implicit trust in the UN in setting priorities and obtaining technical and financial support for the restoration of damage and loss to our natural resources when we present the Melamchi drinking water scheme as an exemplary representation of the highland climate change impact. We should tell the world that the climate crisis in the Himalayas is putting the country's largest and most expensive drinking water project at sustainability risk.  

(Adhikari is an engineer and served Nepal government in various high level capacities.)