The tank has survived several calamities since construction. In 1934, it survived the 8.0 magnitude Nepal–India earthquake. During the Second World War, the reservoir, along with the Howrah Bridge and Kolkata Port, was under the constant threat of Japanese aerial bombings on Calcutta. The British were worried about this because it was the city's biggest reservoir. To prevent it from being bombed, grass was planted on top of the tank so it resembled an open field from above.