A few weeks earlier, the archaeology crew took several fistfuls of silt out of a 10x10 trench with the help of community labourers. They all gave a simultaneous gasp as their eyes grew wide. They scrubbed generations of mud away with shaky mud-stained hands.

At the excavation site in Rakhigarhi, Haryana, they had long suspected the presence of a water storage system from the Harappan era. However, their finding that day surpassed all expectations—they found a massive reservoir, second only to the one at Gujarat's Dholavira. Rakhigarhi, one of the largest cities of the Harappan civilisation, which existed between 2600 and 1900 BCE, covers 500 hectares—almost twice the size of Mohenjodaro. However, much of this area remains undiscovered. The December 2024 excavation revealed a complex and advanced water management system. Previously, wells were only found in Mohenjodaro and Harappa.

“Rakhigarhi was excavated many times, but no information about a reservoir was found until now,” said Sanjay Manjul, joint director general of the Archaeological Survey of India (ASI) and excavation director at Rakhigarhi. “For the first time, a water storage area with a depth of about 3.5 to 4 feet has been revealed at Mound 3. The findings will help in understanding water management during the mature and late Harappan periods when rivers began drying, and people started storing water.” The reservoir also helps geologists and archaeologists in their ongoing studies of the River Saraswati. 

The primary Saraswati channel, the Drishadvati River (also called the Chautang River), began to dry up around 3000 BCE during the mature and late Harappan periods. The diminishing river was probably the reason for the reservoir. Only 400 meters from the Rakhigarhi site, paleochannels from the dry Drishadvati have been confirmed by remote sensing data. Archaeological findings over the last 20 years have repeatedly substantiated the Rig Vedic description of a powerful Saraswati River. The Saraswati, which is said to have flowed from the Himalayas to the Arabian Sea, eventually vanished, leaving behind nothing but traces. The Rig Veda also mentions the Drishadvati as a significant Saraswati tributary. “Drishadvati is a Vedic river and was the only water source near Rakhigarhi. It is from the time of the Mahabharata,” said AR Chaudhri, professor at the Centre of Excellence for Research on Saraswati River at Kurukshetra University.

Manjul, who began excavating Rakhigarhi in 2022, mentioned that the Drishadvati River was once crucial for the region. He added that the discoveries show the advanced water storage techniques used by the Harappans. The site had previously been excavated several times by archaeologists Suraj Bhan, Amarendra Nath, and Vasant Shinde. This discovery comes nearly 100 years after Sir John Marshall identified the Indus Valley Civilization in 1924. “About 5,000 years ago, when the river started drying up, people needed to store water for their personal needs, including agriculture. These findings will give us an idea of the pattern of water management and how a society used to think,” he said.