Wells in every household could provide up to a quarter of second-class water, according to estimates compiled by the Malta Resources Authority.

Launching a funding scheme for the restoration of domestic wells, CEO Anthony Rizzo said only 13 per cent of rainwater was being harvested by homeowners.

“Malta is one of the driest countries in Europe. We simply cannot afford not to make full use of ground and rainwater anymore,” he insisted.

We depend almost exclusively on reverse osmosis plants, yet we allow millions of litres of rainwater to go to waste every year

A 2001 census by the Agriculture Department revealed that the 9,000 agricultural wells scattered across the island could store a potential two million cubic metres of rainwater every year.

Mr Rizzo insisted that if every home had a functioning well the country could harvest at least 4.5 million cubic metres of water, drastically lowering the amount provided via reverse osmosis.

“We depend almost exclusively on reverse osmosis plants, yet, we allow millions of litres of rainwater to go waste every year. This just can’t go on,” he said.

Some 60 per cent of second-class water is provided through reverse osmosis with the rest coming from groundwater extraction.

Mr Rizzo insisted that harvesting rainwater would not only provide a green alternative but also minimise the amount of storm water run-off.

The restoration grant is a pilot project and has a budget of €100,000. The fund will finance up to half the total expenses to a maximum of €1,000 and cover certification fees of up to €100.

The installation of plumbing and sewage systems for water collected in refurbished wells will also be covered.

Mr Rizzo urged homeowners to take up the initiative, insisting that the water collected from domestic cisterns could be used in a number of high waste activities. “From washing cars to floors and clothes and even filling pools, second-class water has a number of uses,” he said.

The permanent secretary at the Ministry for the Conservation of Water, Mario Rogers, said the incentive would be coupled with other programmes for the maximisation of ground and rainwater.

Among the programmes will be a method for the harvesting of rainwater in houses with no cistern system and the rehabilitation of abandoned wells.