It really makes you believe that old is gold when a Mumbai building adopts the water harvesting system that was used by the Harappan settlement in Dholavira in Gujarat some 5,000 years ago. The Chhatrapati Shivaji Maharaj Vastu Sangrahalaya, formerly Prince of Wales Museum, became the first heritage structure in Mumbai to adopt rainwater harvesting recently. And, the inspiration came from Dholavira which excelled in water harvesting technology with dams, drains, reservoirs and storm water management that eloquently speak of the engineering skills of builders of that era. Museum director Sabyasachi Mukherjee visited Dholavira to study the ruins and water harvesting system. "We faced seepage problems after monsoon. In summer, water scarcity affected maintenance of gardens. Experts suggested a water harvesting system and we came to know of the Dholavira model. It was found appropriate for our building and we have completed the first phase of the project,' he says. The Harappans created around 16 reservoirs of varying sizes and designs and arranged them in a series. In the museum building too, channels have been made on all four sides and connected to a bore well. "The water harvesting system at Dholavira shows the engineering skills of the Harappans, who converted city walls into veritable reservoirs to preserve every drop of water,' says director of archaeology in Gujarat, YS Rawat. Dholavira site Six water tanks, one east of castle and five south of it Check dams and series of reservoirs, both rock-cut and made of masonry are first-known examples of water harvesting in Harappan context One of the large reservoirs, eastern reservoir, has a rock-cut step-well