Kathmandu, April 14:

The government’s plan to construct a 71-km-long Outer Ring Road around the Valley could disrupt supply of underground water in the existing residential areas and escalating the existing water crisis, experts have warned.

At present, over half of the demand of drinking water is supplied from underground water sources by the government as well as private water suppliers.

According to statistics of Nepal Water Supply Corporation (NWSC), the average water demand of the valley is 22 million litres per day. Against this, the government provides only 17 million litres in the wet season and 10 million litres in the dry season. The rest of the water demand is met by private tankers, most of which also supply underground water.

According to data complied by the NGO Forum for Urban Water and Sanitation (NGOFUWS), there are 300 deep bored water plants in the Valley.

Geologically, water beneath the surface of the Valley is collected through catchment areas around the Valley. Experts say once the fringes of the hills around the valley are converted into built-up area, it would block supply of underground water in the Valley and create a disaster for the residents.

Dr Suresh Raj Shrestha of the Central Department of Geology at Tribhuwan University said that the construction of Outer Ring Road would adversely affect supply of underground water in the valley.

“The underground water level of the Kathmandu Valley is already falling. An increase in built-up area on the foothills around the valley would mean blocking natural recharge system of the underground water,” he said.

The water level will obviously suffer if catchments of the Valley are turned into residential areas after the Outer Ring Road is built, according to Shrestha.

Padma Sundar Joshi, executive director of the Centre for Integrated Urban Development, said that the construction of Outer Ring Road would affect the Valley residents in several ways.

“First, road construction in our context will obviously draw more population around the area. But their water demand will not be fulfiled. Next, construction of road and houses is ‘surface sealing’ and will stop water recharging beneath the ground. And, the deeper you go to find water, the greater the possibilities of finding high concentration levels of minerals in the water,” he said.

Joshi suggested increasing the vegetation cover in the surrounding areas so that the ground would be able to retain more water, thus facilitating greater water supply. But the government is yet to realise the disaster the Outer Ring Road may bring. Ramesh Sharma, an engineer at Outer Ring Road Development Project admitted that the construction of the road and extension of residential area along the road would invite long-term problem.