After flushing out the tunnel of the Melamchi water project for nearly a week, the tunnel is now being filled with water from the Melamchi river in Sindhupalchok.

The tunnel testing of the Melamchi Water Supply Project had started on February 22 when water was released into the main tunnel in the intake area at Helambu Rural Municipality-1, Sindhupalchok.

After 12 days of its release from Sindhupalchok through the more than 26-km-long tunnel, the Melamchi water had reached Sundarijal on March 6, marking a symbolic achievement for the project.

However, the water was released only for cleaning up the tunnel that will carry water from the Melamchi river to the valley. The wastewater was later released into the Bagmati River.

According to Rajendra Prasad Pant, senior divisional engineer and information officer with the Melamchi Water Development Board, the main body responsible for implementing the national pride project, the flushing of the tunnel has been completed now.

“We had allowed water into the tunnel as part of its testing. The wastewater has been flushed into Bagmati River,” said Pant.

The release of Melamchi water into the Bagmati River was stopped on Friday afternoon. Now, the Melamchi water is being used to fill up the tunnel.

According to Pant, 260 litres of water per second is being released into the tunnel.

“It will take a few more days till the tunnel is completely filled with Melamchi water,” said Pant. “The collected water will not be released into Bagmati River but into the water treatment plant built at Sundarijal.”

Water from the treatment plant at Sundarijal will be supplied to the households of Kathmandu Valley.

“To extract water from the tunnel, it has to be filled up first. Once it is full, water will be let out from a pipe that has been installed in the upper part of the tunnel at the outlet,” said Pant. “The 1,600 mm diameter steel pipe will carry the Melamchi water from the tunnel to the treatment plant in Sundarijal.”

Two water treatment plants—each with a capacity to hold 85 million litres of water—have been built for storing and treating the water before it is distributed to Valley residents.

The Melamchi Water Supply Development Board plans to examine the distribution network after water from the tunnel is brought to the treatment plant at Sundarijal. However, the exact date of the water reaching Valley residents has not been fixed yet, according to Pant.

“Another round of testing will take place for examining the distribution network. There are bulk distribution networks and reservoirs which need to be tested first,” said Pant. “Only then water will be released to the general public.”

The national pride project is expected to divert 170 million litres of water a day to the Valley from Melamchi river in Sindhupalchok district in the first phase.

The Project Implementation Directorate, which is responsible for developing infrastructure for supplying water from Melamchi to Valley residents, has constructed nine new reservoirs for storing Melamchi water. Most of the pipe laying works for supplying water to the doorsteps of Kathmandu residents have also been completed.

“The Project Implementation Directorate has also made preparations for supplying the water from Melamchi,” said Pant. “For now, water can be supplied through the distribution network that was tested earlier or through the existing old pipeline network. We are planning to release water from the tunnel to the treatment plant in two weeks.”