The city has 8 million inhabitants and its altitude has dropped 8.5 cm in 1985, 6.2 cm in 1986 and 4.3 cm in 1987, 19 cm in three years. This is due to the narrowness of the water table under the city.
The immense underground lake under the Tianjin, due to the excessive pumping of water, is losing water year after year and does not keep the soil on it.
The Tianjin authorities have decided not to remove the water from the wells so that the sinking of the city is slower.