A study is underway to provide a permanent solution to potential flood hazards recurring in the Melamchi drinking water project area. One option being discussed is to shift the intake area.

In March 2021, water from the Melamchi River finally made it to a thirsty Kathmandu after decades-long wait, countless deadline extensions and billions in expenses.

But the long-expected torrent from the Melamchi Water Supply Project, which was to rescue the parched valley, was held up by another setback a few months later.

In June 2021, a raging Melamchi River destroyed the headworks besides submerging much of Melamchi town.

Water from Melamchi is currently being channelled to Kathmandu using a temporary arrangement. The water is treated at the Sundarijal plant before it is distributed to the households.

The supply, however, remains uncertain during the monsoon, which generally begins in mid-June and lasts until early October.

Authorities have been waiting for the damage assessment study which is being conducted with technical support from the Asian Development Bank.

The report will recommend a permanent solution for the headworks.

Headworks include the structures constructed on the river for diverting the river water towards the tunnel or canal.

“The study team has proposed shifting the intake site that would be more appropriate in terms of both costs and resilience rather than recovering and upgrading the current site,” said Kamal Raj Shrestha, executive director of the Melamchi Water Supply Development Board, the government body that oversees the Melamchi water supply project.

“They have estimated it might cost more than $100 million (Rs13.28 billion) to stabilise the landslide-prone area in front of the current headworks alone.”

The site recommended for the new intake lies 400 metres upstream from the existing intake. A new tunnel will be needed to connect the new intake and the main tunnel.

The estimated cost for making the new intake, according to Shrestha, is around Rs1.5 billion. “The new site is more secure as it sits on the bedrock,” he said.

The national pride project currently supplies 170 million litres of water daily to the Kathmandu Valley by diverting the Melamchi River in the Sindhupalchok district, as part of its first phase plan.

In the second phase, the project is estimated to fetch 170 million litres of water each from Yangri and Larke rivers, supplying 510 million litres of water daily to the Valley.

According to Shrestha, that might cost around Rs15 billion, based on current estimates, to complete the second phase of the project.

“An 11 kilometre-long tunnel will be built beside the two headworks to divert the water towards the main tunnel,” said Shrestha. “The 26.3 kilometre-long main tunnel has the capacity to supply 510 million litres of water per day.”

The final report is to be submitted by June this year, according to Shrestha.

However, environmentalists say the debris collected upstream from the proposed intake site since the 2021 disaster still poses a threat downstream.

Shifting the intake might be the best possible alternative for the authorities, but first, the risks posed by debris collected upstream needs to be assessed.

“The area might not witness rainfall similar to the one which caused the flooding in 2021, but the debris which remains loose can flow downwards anytime,” said Madhukar Upadhya, senior watershed expert.

Shrestha, from the Melamchi Water Supply Development Board, argues that the 2021 floods were a rare disaster and highly unlikely to happen in the area in near future.

“The normal rain and floods will not bring the debris down,” said Shrestha.

Even in the worst-case scenario, if the debris, which has remained collected 20km upstream, flows downwards, the new site recommended for the intake does not allow the deposition of the debris, said Shrestha citing the study team.

According to a report by the International Centre for Integrated Mountain Development, the Melamchi disaster in 2021 cannot be attributed to a single factor.

“It was the result of multiple anthropogenic and climatic factors and processes that occurred at various locations along the Melamchi River,” the report said.

“This disaster was initiated by intense precipitation in the upstream areas, which triggered cascading hazards along the river corridors, causing loss of life and extreme devastation to settlements, markets, roads and bridges, and local livelihoods.”

Upahdya argued that without assessing the situation of the debris upwards, the authorities will only be inviting more disaster risks by shifting the intake.

Until the project gets a permanent solution, authorities also have plans to upgrade the current mechanism to supply water throughout the year.

“While the short-term solution is to upgrade the current system to supply the water for around 10 months in a year, except during the peak flooding period, the mid-term one aims to supply the water throughout the year,” said Shrestha. “It may take at the most Rs40 million to materialise the short-term plan and Rs 500 million for the mid-term one.”

“A detailed estimate is being made,” Shrestha added. “The Asian Development Bank is likely to provide a grant for it.”

Mandira Singh Shrestha, programme coordinator for Climate Services at the International Centre for Integrated Mountain Development, said a detailed risk assessment is required before developing further infrastructure. “We will only be putting the resources at risk,” she said.

As matters stand, around Rs60 billion have already been spent on bringing water from Melamchi.