Before Typhoon Lekima made landfall, removable aluminum alloy floodwalls were installed along a river bank in Yuyao, East China’s Zhejiang Province. Photo: Courtesy of Lei Dong

Domestically-made metal floodwalls have helped Chinese cities resist floods caused by super Typhoon Lekima at half the price of foreign products.

The walls have been set up at key places for flood control, including river banks, bridge heads and intersections in Shouguang, East China’s Shandong Province  since May as the city’s latest improvement in flood control, after half a million Shouguang residents suffered and 60,000 were relocated for flooded areas last year, according to a report of the Science and Technology Daily on  Wednesday.

As Lekima brought torrential rain and floods which overflowed concrete dykes and submerged bridges in Shouguang over the weekend, the walls kept floodwaters in a hanging river and protected city centers and low-lying places from being submerged. 

Lei Dong, the floodwall’s developer, told the Global Times on Wednesday that the walls are made of aluminum alloy plates that can hold back large amounts of floodwater. 

“They are easy to assemble to a desired height,” said Lei, who is also a professor at Hohai University in Nanjing, East China’s Jiangsu Province.  

Two people can assemble a 100-meter-long, two meter-high floodwall in an hour, while higher walls require a small hoist, Li said. 

If it was not for the walls, the city center of Shouguang would have been destroyed by the floods, residents and property would have been threatened, a local resident named Wang Tinglin was quoted as saying by the Science and Technology Daily. 

Removable floodwalls were first adopted by Germany in 1984, and are now widely used in countries like France and Austria. 

Lei said China is a latecomer due to the wall’s high cost and maintenance. But the domestic ones only cost between 3,000 ($427) and 4,000 yuan a square meter, which is roughly half the price of their foreign counterparts. 

Besides Shouguang, Yuyao in Zhejiang Province, Changzhou and Wuxi in East China’s Jiangsu Province also installed removable floodwalls to defend against Lekima. 

While many Chinese cities still use sandbags to hold back floodwaters, which are time- and labor-consuming, more of them are preparing to use such floodwalls, and the market is huge, Lei said. 

Lekima, which is estimated to be the strongest since 1961, has claimed 56 lives with 14 still missing in more than ten provinces as of Wednesday,  China’s National Climate Center announced on its website.