I was reading a few pages from Dying Wisdom - Rise, Fall and the Potential of India's Traditional Water-harvesting Systems edited by Sunita Narain and Anil Agarwal, and I came across this interesting piece on stepwells or vavs of Gujarat that were mainly built between the 8th and the 14th centuries.
"The construction of a stepwell was usually associated with elaborate rituals and was an important event in the lives of the people. The construction of a big tank or well would begin with the king or the village chief making the first mark on the ground with a spade, while the priest chanted hymns, a ceremony called Vastupujan. Later on, the people of the area would continue digging under the supervision of the master constructor. The normal season for digging was after the harvest, when the sun is at its hottest and the land dry. After construction was over, the stepwell was consecrated with much pomp and show. Brahmin priests would declare the water to be holy and prescribe active use of it..."
While stepwells were used for utilitarian and irrigation purposes and as a cool place for social gatherings, they were also used for polishing weapons.
"Minerals, salts and other substances dissolved in the water of a stepwell often had the quality of brightening or strengthening materials, either cloth like satin, silk and cotton or metals. It was widely believed that the water of a stepwell called sari, in southern Saurashtra, added to the temper and sharpness of swords."
It's a pity that most of these stepwells have disappeared and the ones that remain, such as the ornate Ranki vav at Patan, exist only as monuments.