More than 11,000 parks in Delhi will soon be watered with wastewater to tackle water scarcity in the region.

The Municipal Corporation of Delhi (MCD) has announced plans to construct underground reservoirs to collect and supply treated wastewater for irrigating parks, reducing reliance on groundwater. A senior municipal official from the horticulture department said that surveys of large parks in Keshavpuram and Rohini zones are being carried out to identify potential sites for these underground reservoirs.

MCD said it aims to replace irrigation water with treated wastewater in over 11,869 parks.

According to the World Bank only 18% of the world's treated wastewater is reused for irrigation, which is most common in arid and semi-arid regions, where freshwater is scarce. The US is the world's largest user of recycled water, with around 4% of the country's treated wastewater reused for irrigation.

Also known as recycled water or effluent, the wastewater is treated to remove harmful bacteria and other contaminants. Depending on the water quality specified and the technology applied, recycled wastewater can be used for many other purposes, including industrial uses and even for drinking water.

There are several benefits to using wastewater for irrigation. It can help conserve freshwater resources, reduce the need for chemical fertilisers, and improve soil quality. Recycled water can also help reduce the amount of wastewater sent to treatment plants and landfills.

The use of recycled water for irrigation is a growing practice around the world. When properly managed, it can be a sustainable way to use water resources and reduce the environmental impact of water use.