Nepal on Monday initiated the testing process of the tunnel for the country's largest drinking water project, a senior official of the project office said.

Water Supply Minister Mani Chandra Thapa on Monday inaugurated the testing process by releasing water into the tunnel of the Melamchi Drinking Water Project after the Chinese contractor Sinohydro Corporation Limited completed digging the tunnel.

The project office said it would take around 17 days for the 27.5-km tunnel to be fully filled with water and then the tunnel will be in a full-load state for two months to see if there is any leakage or other problems.

"If no problem is seen in the tunnel during the testing process, the Kathmandu Valley will get water from the project after two months," Rajendra Pant, spokesperson at the Melamchi Water Supply Development Board, an implementing agency of the project, told Xinhua on Monday.

The existing sources of water available in the Kathmandu Valley are insufficient to meet the rising demand with growing population. The drinking water project was launched in 2000 in a bid to address the shortage of water.

As per the population census of 2011, the population of Kathmandu Valley is around 2.5 million and the population is estimated to have grown much higher now.

The project aims to supply 170 million litres of fresh water per day. Together with available water supply, the commissioning of the Melamchi project is expected to largely relieve the water shortage in the valley, Nepali officials said.

The project was delayed due to a number of factors including the devastating earthquake in 2015.

In September 2019, Sinohydro was awarded a contract of completing the remaining works of both tunnel and the headworks.

"The Chinese contractor was doing most of the work as per the schedule. But, the COVID-19 pandemic affected the works to some extent as some construction materials could not be arranged during the lockdown imposed in early last year to tackle the pandemic and technical human resources could not be brought from China," said Pant.

The tunnel work was supposed to be completed in October last year. Most of the works of headworks will be completed by April, according to Pant.