Kathmandu, October 24:

Rainwater harvesting can be one of the best ways for households in the valley to cope with prevailing scarcity of water, according to an expert.

According to him, 102 thousand litres of rainwater can be collected annually in a house built in an area of two-and-a-half annas of land.

The daily demand of water in the valley is about 220 million litres, but only 160 million litres of water is supplied per day during monsoon. The daily supply dips to 90 million litres during the dry season, leading to an acute shortage of water. Water supply in the valley has always been insufficient, Prakash Amatya, executive director of the NGO Forum for Urban Water and Sanitation, told this daily. “Rainwater harvesting is one of the simplest and long-term solutions to the problem of water scarcity.”

Rainwater harvesting is a systematic collection of rainwater from catchments like terraces or roofs of houses.

The annual precipitation is around 1,600 millimetres in the valley and this much of water is enough to meet the demand for water, said Amatya. Harvested rainwater can meet the demand for water during the rainy season. Surplus water can be used to recharge sources of water and groundwater used to meet the shortfall of water during the dry season, he said.

It does not cost much to install a rainwater harvesting system. “If a new house is being constructed, this system can be put in place with a very simple alteration. It takes a minimum of Rs 1,500 to install the system in an old house,” Amatya said.

According to Amatya, over 1,000 houses in the valley are equipped with rainwater harvesting system. More and more such units should be installed to curb water crisis, Amatya said. People are likely to install this system in their households if the municipalities offer them some discount.

Nine municipalities in the country, including five in the valley, have set-up information desks on rainwater harvesting. “Partnership between the NGOs and the government can help raise awareness on the matter and end the water crisis,” Amatya said.