National Water Company (NWC), the biggest water supplier in Saudi Arabia, plans to build a water storage facility with a capacity of 4.6 million cu m in the capital Riyadh at an investment of $480 million, said a report.

This is part of a bigger project aimed at achieving a sustainable and secure water supply to meet the future challenges in the kingdom's largest city, reported the Saudi Gazette.

NWC said, this year alone, the government has allocated $4.42 billion for desalination projects to cope with the potable water needs of a population that has quadrupled in 40 years to 30 million.

The second phase of the project, the biggest in Saudi Arabia in term of water storage, will see NWC build another storage facility at an investment of $693 million.

The storage unit, which will have a capacity of six million cu m, will serve the city's five million residents, the report added.