From 2010 to 2013, the average water level of Seokchon lake was lowered from 4.63 meters to 4.17 meters. About 4 million tons of water was leaked from Seokchon Lake. Also, several large underground voids and sinkholes were observed near the lake and caused controversy about safety problems. According to an investigation by the City of Seoul, it was caused by massive underground operation from the construction of Lotte World Tower and Seoul Subway Line 9. In 2013, the City of Seoul started supplying water to maintain the lake's water level. As of 2015, the lake had an average water level of 4.8 meters.
