Groundwater in North China is over exploited by 120 billion cubic meters, an amount equal to the total water reserves in 200 lakes of Baiyangdian, the largest freshwater lake in Hebei, the People's Daily Online reported Friday, citing earlier official statements.

"In fact, the situation may be worse," the website quoted an anonymous expert as saying, adding that the amount of groundwater that was over exploited may have approached 200 billion cubic meters.

The world's largest groundwater depression cone has already formed in North China because of the continuous fall in the areas' groundwater level, the website said.

Wei Zhimin, a noted expert on water resources in Hebei province, said more than 20 depression cone areas have formed in the North China Plain, covering an area of 50,000 square kilometers.

In Tianjin, people have to dig as deep as 110 meter to find groundwater; and Hebei's deepest pump pit in Changzhou reaches 800 meters underground, said Wei.