CHANGCHUN -- Workers in Northeast China's Jilin province began dismantling an old dam at the Fengman Hydropower Station, one of China's oldest large hydropower plants on Tuesday.

The 80-year-old dam stretches more than 1,000 meters over the Songhua River and is a safety risk due to its deteriorating condition. Its image was once on the 50-cent note of Renminbi yuan.

It will be demolished by controlled blasting and the dismantling is expected to be completed by April 2019, according to Meng Jihui, an engineer responsible for the demolition work.

About 120 meters downstream from the old dam, a new dam has been built with a total installed capacity of 1,480 megawatts, nearly 1.5 times that of the old dam. Its power generating units are expected to start operation in June 2019.

"The new dam will increase the share of clean energy in Jilin's energy structure," said Lu Zhengbao with the State Grid Jilin Province Electric Power Supply Company, a subsidiary of China's utility giant State Grid.

The new dam will also have a higher capacity against flood and fish ladders to facilitate fish migration.

"Nearly 400 meters of the old dam will be preserved as an important anti-Japanese war and industrial heritage," Meng said.

Construction of the old dam started in 1937 when northeast China was under Japanese occupation, but it was poorly built. In the early years following the founding of the People's Republic of China in 1949, Fengman Hydropower Station was built into the largest hydropower station in Asia at that time.