The swollen Yamuna river has reached the walls of the Taj Mahal here, a development only witnessed in 1978 and 2010, even as the Archaeological Survey of India said the increased water levels pose no threat to the iconic monument. According to officials, the water level crossed the ‘medium flood level’ of 499 feet. It reached 499.97 feet here on Tuesday due to which the water touched the walls of the Taj Mahal and submerged a garden behind it. An official of the ASI’s Agra Circle said the main mausoleum is designed on a raised structure which stands on ‘Chameli farsh’ and is built on a foundation of 42 wells supported by a structure of sal woods. ”The Yamuna waters touched the walls of the Taj Mahal in 2010 and prior to that in the year 1978. In the 1978 flood, water had entered rooms in the monument’s basement,” Prince Vajpayee, conservation assistant at Taj Mahal, told PTI. ”This year as well, the water has reached the Taj Mahal, but it is not a threat to the monument. The main mausoleum is standing on a raised platform. It is standing on the Chameli farsh, and in the foundation it has 42 wells and a structure of sal woods over the wells,” he said. Chameli farsh is made up of red sandstone and white marble, the official said. Recalling the 1978 floods, Raj Kishore Raje, a historian of the Agra city, said, ”That year, the Yamuna crossed ‘high flood level’ of 508 feet in Agra following which the floodwaters entered rooms of the basement (of Taj Mahal) under the Chameli farsh. The rooms were filled with silt.”