China is facing a set of threats it can no longer ignore.
In September 2021, at the United Nations General Assembly,
President Xi Jinping announced bold promises:
It marks a shift in China's government policies.
A country that has experienced breathtaking exponential growth and
thrived over the past few decades, China rose from a poor geopolitical outcast
to being the world's factory and then an economic powerhouse.
But this immense growth of wealth and power
alongside rapid modernization
came at a huge cost.
Like many other countries,
China is facing a multitude of water related challenges,
including flooding and droughts,
which are linked to environmental pollution and climate change.
The country's water based problems have increased in both intensity and frequency,
impacting not only public health and society,
but also infrastructure and the environment, resulting in huge economic losses.
This led the government to take action
and completely rethink the way their cities operate.
China is a vast and geographically diverse country.
The fertile lowlands of the east are surrounded by the arid north,
the alpine west and a long coastline.
Its population, however, is extraordinarily urbanized:
more than 60% or almost 900 million people, live in cities.
It's a number that has more than tripled since the 1980s.
94% of China's population lives east of this line, where all the major cities are located.
And these cities are growing fast - at an unprecedented pace!
By 2035, 70% of the Chinese population
is projected to live in urban areas.
This comes with two key challenges:
to supply the mega cities with water, but also to keep it out.
The solution is an innovative yet totally straightforward concept:
Sponge cities.
The principal of the Sponge City is simple:
let the soil beneath the urban area interact extensively with the surface,
sucking up as much water as possible and releasing it over time.
In short: allow the earth to act as a sponge.
The expansion of a city automatically means
the construction of roads, railway lines and paved surfaces.
The ground is sealed, reducing the number of possibilities for rain to be absorbed,
and disrupting the natural hydrological cycle of the area.
So, instead of building more man-made structures like dams and other barriers,
the Sponge City concept focuses on turning gray into green:
bringing back nature and intertwining it with the urban surroundings,
welcoming the water instead of holding it back.
The concept was conceived in 2013
by Professor Kongjian Yu,
in an effort to control and mitigate flooding, water pollution
and water scarcity in urban spaces.
"What can we do?"
A new type of Chinese eco city aims
to offer a holistic strategy to implement an urban water cycle.
The key features of the Sponge City are to be environmentally adaptive,
systematic and comprehensive.
Yu envisioned urban infrastructure, a systems that absorb,
store, infiltrate and purify rainwater.
This is achieved through contiguous open green spaces with interconnected waterways,
green roofs and porous building materials that allow water to be absorbed.
These are combined with smart monitoring systems
to improve water savings and recycling.
Only two years later, in 2015,
the Chinese government made Sponge Cities a state doctrine.
30 cities were chosen to implement the concept,
with the goal for most of these cities to absorb
and reuse more than 70% of their rainwater by 2030.
Decades old pollution problems could be solved with Sponge City projects
like this one here in Haikou, on Hainan Island.
The Meishe River suffered from water pollution for decades,
mainly caused by sewage in suburban runoff.
By transforming the waterway into a resilient green infrastructure
and integrating the sewage treatment process into an ecological system,
the river was revived with clean water and became a lush green space full of life.
But if there's one place
that most strikingly represents the Middle Kingdom's economic resurrection,
overwhelming urbanization and all its attendant issues, it's here:
Shenzhen.
The mere existence of this mega city, its size and present-day appearance,
is a sheer mind-blowing miracle.
Right across the border from the former British colony of Hong Kong,
Shenzhen was just a little fishing village surrounded by rice paddies.
In came Deng Xiaoping,
who became the new leader of the People's Republic in 1978.
He implemented far-reaching economic reforms
to save the country from poverty and international insignificance.
Inspired by cities like Singapore and Hong Kong,
he declared Shenzhen a Special Economic zone - and it worked.
Shenzhen started to grow into a modern city.
At a pace that had never been seen before,
and in just four decades,
the little fishing village swelled into a super modern mega city
with over 13 million inhabitants.
But there's a catch:
the region's main water source is the Dong Jiang,
which is rather unreliable due to its susceptibility to drought.
In 1963, when Hong Kong experienced its worst drought on record,
the mainland had to step in and divert fresh water from Shenzhen to Hong Kong.
Today, though, the situation looks different.
The water stress experienced by the river is exacerbated
by the city's rapidly increasing population and economic activity.
It's estimated that the Dong Jiang holds 55% less water than it did in previous years,
causing widespread concern in the region.
Many think that the Sponge City approach
has great potential to mitigate these issues.
Shenzhen is in fact one of the chosen pilot cities,
yet the measures here are mainly seen as a means of reducing flood risk,
without addressing the need for water management and meeting demand.
To tackle water scarcity,
the Sponge City is an effective innovation for reducing demands made on fresh water sources
and increasing water supply through reusing rain and waste water.
There's still a long way to go
before urban water management becomes entirely sustainable,
can tackle all the water-related problems and risks of our changing climate,
or succeeds in exploiting the full potential of reusing fresh water.
But major steps are being taken in the right direction,
with Sponge Cities forming an integral part of this.
The concept is, by all means,
a potential path to sustaining long term water security across China ...
and the rest of the world.
With this series we are following water related problems across the globe.
But we are also examining promising and innovative solutions for it.
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There's much more coming up.