Light at the end of the Melamchi tunnel
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Nearly 25 years after it was first mooted, there is light at the end of the tunnel for Melamchi, Nepal’s biggest and most expensive infrastructure project that will pipe glacier water from Langtang National Park to Kathmandu Valley.
The $800 million undertaking has been near completion several times, but government interference, corruption and extortion have taken their toll.
The headworks construction is now half finished here at Ambathan 70km by road north of Kathmandu where the roar of the Melamchi River drowns out the sound of excavators that will allow the water into the tunnel.
On Sunday, the project sent water 800m down the tunnel to its first adit tunnel as a test from the overflow reservoir at Ambathan. At this rate, project officials say the first Melamchi water could flow down to Melamchi by September.
They say 99% of the 26.5km long tunnel and the treatment plants at Sundarijal in Kathmandu Valley are complete. Kathmandu roads have been dug up and used to be shrouded in a perpetual pall of dust as new water mains were laid to distribute the water when it arrives.
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The new target date for consumers to actually get Melamchi water flowing through their pipes is late 2020, but even that could be delayed due to the COVID-19 lockdown.
The Melamchi Water Supply Project is the largest infrastructure scheme in Nepal today, and with a $800 million price tag, including the future extension, the costliest as well. Its 26.5 km long and 3.7m wide tunnel in Phase 1 is the second longest tunnel for water supply in Asia.
It is being built with a soft loan from the Asian Development Bank (ADB) and will bring 170 million litres a day to Kathmandu. A proposed Phase 2 of the project could also connect the Yangri and Larke Khola through two more tunnels and nearly triple the daily water flow (see map).
The project has been plagued by chronic delays due to political meddling, the 2015 earthquake, the Indian blockade and most recently by the COVID-19 lockdown. It was 2010 when a Chinese contractor finally started digging the tunnel but could only finish 6.4km in three years. It was replaced by the Italian CMC di Ravenna company which took over where the Chinese had left off. The earthquake and blockade led to more delays.
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But the project could not meet its completion date of March 2018 because the government cancelled CMC di Ravenna’s contract, reportedly because it refused to pay extortion to bureaucrats in Singha Darbar. China’s SinoHydro then took over, and had been rushing to catch up with the schedule when the COVID-19 lockdown hit.
Contrary to popular belief, the water will not be gushing through the tunnel. In fact, it has a gradient of only 8m between the intake in Melamchi and the outlet in Sundarijal giving it a water velocity of only 0.5m/second which means it will take 45 hours for the water to complete its underground journey.
This is the monsoon, and the water flow in the Melamchi makes it a raging torrent. However, in the dry season flow goes down to 2.4 cubic meters per second (cumec) of which only 2 cumec of water will be diverted into the tunnel. There are 1.5 km of access tunnels located near the intake in Ambathan, in Gyalthum and Sindhu.
On 5 July, the first water was let into the tunnel amidst a religious ceremony. Tiresh Khatri of the Melamchi project said: "This is a milestone, we will be doing more tests and hopefully water will reach Kathmandu by September."
However, engineer Shekhar Khanal said there still a lot of unfinished work that will take months. His estimate for water to reach Kathmandu: early 2021.
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