The Wujiang River, which flows through Yu's home province of Zhenjiang, was recently rehabilitated.

'Do not fight with water'

What if a flood is something we can embrace and accept without being frightening? This is the heart of Yu's Sponge City.

Routine floodwater management involves building pipes or drains, draining water as quickly as possible, or reinforcing riverbanks with concrete to ensure they do not overflow.

The rain soaks up the water intermittently, trying to slow the surdata-face flow. That is, the earth must absorb the floodwaters like a sponge. 

Like a sponge with many holes, the city is trying to control the flow of water by creating multiple pools.

Second, waterlogged areas. Instead of carrying the water out of the river in a straight line, it flows through curved canals, slowing the flow. 

The third is where the water goes and joins. The river joins the lake or the sea. 

Sponge City is notable for using natural processes to solve the city's problems, although similar ideas are found elsewhere.

Most of Yu's ideas are influenced by old farming techniques. These include storing water in the pond for crops. He learned these things while growing up in Zhejiang, the east coast province of China.

The technology developed in european countries cannot be adapted to the monsoon climate. 

Initially, he had opposition from the government. Many were angered by his criticism of glorious Chinese projects, including the Three Valley Dam.

I’m not a Westerner, I’m a Chinese conservative, he says with a smile. We have thousands of years of experience and we have a solution you can't ignore. We have to grasp our Chinese ways.

His comments were aired in the media following the recent floods in beijing and Wuhan.

By 2030, targets have been announced that 80% of urban areas in china should have sponge city components and at least 70% rain recycling.

Is this a magic bullet?

They are struggling to cope with the high rainfall around the world. Scientists link this to climate change. 

As the temperature rises with global warming, excess moisture evaporates into the atmosphere, causing heavy rainfall.

In the future, rainfall will be more intense and heavier than previously expected, the researchers say. 

But will the city of Sponge be the solution to severe storms? Some experts are sceptical.

He also says it may be difficult to implement Yu's plan for densely populated cities.

But Yu argues that ancient Chinese knowledge could not be wrong. He also considers the failures to be due to local authorities implementing his idea incorrectly or fragmentally.

He says the floods in Zhengzhou earlier this year are a prime example. He says the city has not been able to store enough water overhead because it has built sidewalks over its ponds.

Another question is whether the concept of a sponge city can be implemented in other countries.

But it has been argued that the success of Sponge City across china is due to its central government concentrating its power. 

Using concrete to manage to flood is like drinking poison to quench thirst. We have to change the way we live according to the climate. If they do not follow my solution, they will fail.