Share This

Monday 29 January 2018

Absorb New ways to prevent floods

Sponge City: Solutions for China's Thirsty & Flooded cities

 China's 'sponge city' projects may be worthwhile examples for Malaysia.


"Only about 20~30% of rainwater infiltrates the ground in urban areas, so it breaks the naturual water circulation.- Wen Mei Dubbelaar"

Last week, it was the turn of Petaling Jaya, Gombak and Sungai Buloh to be the latest major urban areas in Malaysia to suffer flash floods (Flash floods wreak havoc in PJ - Nation). Scenes of cars and buildings submerged in muddy water are now almost an everyday thing. The focus should now shift from the bad situations to the solutions.

It was also last week that I attended a briefing organised by civil society groups for Penang and Seberang Perai municipal officials and members. The briefing was on the recent floods.

Later, I came across several articles on how China is turning 30 of its flood-prone areas into “sponge cities” to prevent floods and retain rainwater.

The Chinese plan big and fast. It launched the sponge city project only in 2015, but it aims to retain 70% of rain in 80% of urban areas by 2020. The sponge concept is set to spread rapidly as part of global efforts to reduce the impact of increased rainfall and floods, and climate change.

The concept figured prominently at the briefing chaired by Penang state exco member Chow Kon Yeow. Scientist Dr Kam Suan Pheng introduced it when explaining the floods.

She contrasted the present situation when rain falls with what used to happen. In the past, 50% of the rain seeped through the natural ground cover (trees, grass, etc) and into the ground. There was 10% water runoff (to rivers and drains) and 40% evapotranspiration (water going back to the atmosphere).

The trees and green spaces act as a sponge to absorb the rainwater that infiltrates the soil, preventing the water from building up into flash floods.

Due to urbanisation, the green spaces have been paved over with cement and concrete. Now, only 15% of the rain infiltrates the soil, while the runoff has increased to 55% and evapotranspiration is 30%. The sponge now absorbs 15% of the rainwater compared to the previous 50%.

Dr Kam quoted former Penang Water Authority general manager Kam U-Tee as saying that the October 2008 Penang floods were caused by conversion of the valleys into “concrete aprons that do not retain water”. As a result, the water immediately flowed into streams, causing flash floods, even with moderate rainfall.

Given this analysis, a key part of tackling the floods is to reverse the loss of the sponge. In recent decades, Malaysia has seen the conversion of a lot of farms, parks, trees and grass areas into concrete jungles of roads, houses, commercial buildings and car parks.

There now has to be high sensitivity to the valuable environmental and economic roles of trees, gardens, fields and grasslands, and parks. The aim of garden cities is not just to be pleasing to the eye but to be a very important part of development as well.

Now comes the role of sponge cities. The world is applauding the Chinese initiative to counter floods and improve water security by building up the natural cover (or sponge) in its cities.

In 2010, landslides during flooding killed 700 in three quarters of China’s provinces. Last year, rains flooded southern China, destroying homes and killing around 60 people.

In 2015, China launched the Sponge City initiative, which now covers 30 cities, including Shanghai, Xiamen and Wuhan. The target: by 2020, 80% of its urban areas will absorb and re-use 70% of rainwater.

The many types of projects include:

  • > Constructing permeable roads that enable water to infiltrate the ground;
  • > Replacing pavements on roads and parks to make them permeable;
  • > Building wetlands to absorb and store rainwater;
  • > Constructing rooftop gardens (for example, 4.3 million square feet in Shanghai);
  • > Plant trees on streets and public squares;
  • > Build community gardens and parks to expand green spaces; and
  • > Build manmade lakes and preserve agricultural land to hold water.

“In the natural environment, most precipitation infiltrates the ground or is received by surface water, but this is disrupted when there are large-scale hard pavements,” said Wen Mei Dubbelaar, water management director at China Arcadis, in words similar to Dr Kam’s.

“Now only about 20-30% of rainwater infiltrates the ground in urban areas, so it breaks the natural water circulation and causes water logging and surface water pollution,” said Wen in an interview with The Guardian.

In Shanghai’s Lingang district, the streets are built with permeable pavements. There are rain gardens filled with soil and plants, buildings feature green rooftops and water tanks, and a manmade lake controls water flows, reports The Guardian.

Prof Hui Li at Tongji University said the first thing is to preserve or restore natural waterways as that is the natural way to reduce flooding risk.

The problem in Wuhan is that a lot of small rivers were filled in during building. But Lingang still has agriculture land and a lake to hold more water during heavy rain.

What about the cost factor? So far the cities have received over US$12bil (RM47.4bil) for sponge projects. The central government funds 15-20% of costs, and the rest is from local governments and private developers.

But compare this to the US$100bil (RM395bil) of direct economic losses due to floods in China between 2011 and 2014, plus the human lives lost.

Sponge cities are the way to go for the future. Our own governments – federal, state and municipal – should study this option seriously, as the public braces itself for more floods ahead.

- Global Trends by Martin Khor

Martin Khor is executive director of the South Centre. The views expressed here are entirely his own.


Related Links
 

10 measures to prevent (urban) flooding - Wavin

 

Related posts:


Our Environment is Our Life - YouTube THE year has barely started, and already we have so many reports of weather and climate-related e...

Seeking solutions: Penang Forum member and soil expert Dr Kam Suan Pheng giving her views during the dialogue session themed ‘Penang Fl...


Behind BJ Cove houses at Lintang Bukit Jambul 1 is an IJM Trehaus Project.  Approximate Coordinates : 5°20'38.47"N,100°16'...

PAC blamed Penang Island City Council (MBPP) for failing to enforce laws on hillside development Becoming bald: A view of the clearing work seen at Bukit Relau which was visible from the Penang Bridge in November last year. GEORGE..


Speaking out: Penang Forum members protesting outside the CAP office in George Town. Don’t just make it about worker safety issues ..


https://youtu.be/kslhytLg-Wc Hills, landslides and floods: What to do?   The mega floods in Penang which followed the landslide...

https://youtu.be/yqtdkBsipCU Suspicious activity: A photo taken from Penang social activist Anil Netto's blog showing an active s..

Make environment our 2018 priority

Our Environment is Our Life - YouTube

THE year has barely started, and already we have so many reports of weather and climate-related events.

Heavy wind, snow storms and below-freezing temperatures paralysed cities in the United States’ East Coast. New York’s John F. Kennedy International Airport was in chaos with hundreds of flights suspended.

Yet, just weeks previously, big fires linked to a heat wave were sweeping through parts of California on the West Coast, burning 112.000ha of forest and threatening lives and homes.

Colder weather in one place and hotter temperatures in another are signs of global climate change, which can also cause heavier rainfall and drought in different regions.

While it is difficult to pin down any particular incident as a direct result of climate change, it is recognised scientifically that climate change generally exacerbates extreme weather events and may cause some of them.

We can expect the weather, and more broadly the environment, to figure prominently this year.

The alarm bells sounded long ago on the environmental crisis. But it is not easy to achieve a continuous high level of concern among political leaders.

After a calamity and public outrage, there are pledges to correct the situation. However, the interest fades after a while, and not much action is taken, until the next disaster happens.

In Malaysia, people are now looking at the sky constantly to anticipate whether it is going to rain.

Heavy rainfall has been causing floods in Kelantan, Terengganu, Pahang, Johor, Negri Sembilan, Kedah, Selangor, Sabah and Sarawak.

In Penang, severe state-wide flash floods seem to be occurring every few months, with localised flooding in several areas in between. The mud brought down from eroded hill-slopes into overflowing rivers and then into houses, makes floods an even worse nightmare for those affected.

For some unlucky ones, hardly have their houses and furniture been cleaned than they are under one metre of water again through a new flood.

Heavier rain and more floods is the new normal in Malaysia. There has been an increase in rainfall for most parts of the country in 2000-2009 compared to 1970-1999, with the major increase in 2005-2009, according to a 2012 paper by Yap Kok Seng, then the head of the Malaysian Meteorological Depart­ment (MMD), and his colleagues.

The global temperature increase has led to changes in weather including major wind patterns, amount and intensity of precipitation, and increased frequency of severe storms and weather extremes, according to the paper, Malaysia Climate Change Scenarios.

In Malaysia since the 1980s, there had been increasing number of days of extreme rainfall events, extreme wind events and annual thunderstorm days, added the paper.

Unfortunately the situation will worsen. A study published on Jan 10, whose authors are affiliated with Germany’s Potsdam Institute for Climate Impact Research, predicted that millions more people will be affected by river flooding as global warming increases severe rainfall in the next 20 years.

In Asia, the most affected region, people at risk from floods will rise to 156 million from the present 70 million in the next 20 years.

Global warming increases the risk of flooding because rain during an extreme downpour “increases exponentially” as temperatures rise, the institute’s Anders Levermann told Reuters.

“We have to adapt to global warming. Doing nothing will be dangerous,” he said.

Countries will have to act urgently and make major investments in flood protection to boost their flood defences, according to the report.

This advice surely applies to Malaysia as one of the countries already being affected by heavier rainfall and extensive river flooding.

Flood mitigation measures must be increased, including de-silting, widening and deepening rivers, improving urban drainage, strengthening river banks, redirecting water flows, constructing tidal gates, and pumping excess water into ponds.

Even more important is flood prevention. A main cause of the floods is deforestation, leading to the loss of the forests’ valuable roles in soil and water retention and climate regulation.

It is really short-sighted and irrational to damage and destroy forests, especially forest reserves and water catchment areas.

Exposed soils are swept by rain into rivers, clogging up streams and drains with mud and causing floods downstream in the towns and villages, while also depriving us of much-needed water supply.

There is a great deal of public concern over recent developments that threaten forests and hill lands in the country.

These include the de-gazetting of the Ulu Muda water catchment area in Kedah; the de-gazetting of hill lands in Penang that previously were protected under the Land Conservation Act and which are now being “developed” with the aid of higher permitted density ratio; the conversion of 4,515ha forest reserve to cultivate oil palm plantations in Terengganu (being opposed by WWF-Malaysia); and protests over the imminent loss of a forested park in Taman Rimba Kiara in Kuala Lumpur to make way for housing.

Federal, state and local governments should give priority to environmental rehabilitation of damaged forests and hills, prevent damage to the coastal ecosystem including mangroves, and take comprehensive flood prevention and mitigation measures.

They should stop approving environmentally harmful projects in ecologically sensitive areas.

They must make major financial allocations to protect and rehabilitate the environment, and implement finance measures to prevent and manage the floods.

As so many scientists are warning, and as more and more local communities and citizen groups are demanding, the time to act on the environment is now. Let us hope that in 2018 these calls will be heeded.

Global trends by Martin Khor

Martin Khor is executive director of the South Centre. The views expressed here are entirely his own.

Related posts:

Behind BJ Cove houses at Lintang Bukit Jambul 1 is an IJM Trehaus Project.  Approximate Coordinates : 5°20'38.47"N,100°16'...
https://youtu.be/ooyXvqmxbvw GEORGE TOWN: Some 20 houses located on a slope in Hong Seng Estate in Mount Erskine were flooded due
Wet, wet woes: (Above) Bukit Jambul is flooded once again after an evening downpour. Firemen installing a pump to draw floodwater...
Council should not bow to development or political pressure, says city councilor, Khoo ‘Politicians should be ‘wakil rakyat’ and n...

Seeking solutions: Penang Forum member and soil expert Dr Kam Suan Pheng giving her views during the dialogue session themed ‘Penang Fl...

(From left) Dr Kam will deliver a talk on ‘Understanding the Causes of Floods and Seeking Solutions. State assemblymen expressing inter...
https://youtu.be/4qaOB1n5tgA GEORGE TOWN: The Penang Island City Council has lodged a police report against the consultant of the aff...

Speaking out: Penang Forum members protesting outside the CAP office in George Town. Don’t just make it about worker safety issues ..

https://youtu.be/QB45Q2_mOG0 Suspicious activity: A photo taken from Penang social activist Anil Netto's blog showing an active s..


Some representatives of the 24 residents associations and management corporations showing messages urging the state to resolve the flood...

 Wanted: Leaders who listen !
Turning a blind eye: The grumblings over exposed hills are growing louder but little is being done to rectify the situation   G...

It’s hard to deny when the effects of climate change are all around us  Andrew Sheng says that from increasingly intense hurricanes t...
Why did MBPP approve the Tanjung Bungah development project? Read more at https://www.malaysiakini.com/letters/399357#qbRd534yu1JfC551....

https://youtu.be/kslhytLg-Wc Hills, landslides and floods: What to do?   The mega floods in Penang which followed the landslide...
Becoming bald: A view of the clearing work seen at Bukit Relau which was visible from the Penang Bridge in November last year. GEORGE..

Choong (in white) surveying the deforested hillslope next to Majestic Heights. PENANG MCA has raised concerns about the safety of the r...

Who is sabotaging Penang undersea tunnel project?


Penang govt to blame, says Lau  


PETALING JAYA: Barisan Nasional should not be blamed as it is DAP’s own doing that “sabotaged” the Penang undersea tunnel project, said Gerakan vice-president Datuk Dr Dominic Lau (pic).

He added it began when the DAP-led Penang government failed to provide feasibility reports on the project, which were supposed to be completed by April 2016.

“You missed the deadline and in October 2017, the special purpose vehicle (SPV) said there is no more urgency to complete the reports.

“Based on the original timeline, the first phase of the project was supposed to start construction in the first quarter of 2015 and completed by this year.

“As of now, this first phase has not even started construction,” he said in a statement yesterday.

Despite the multiple delays in the reports and the construction starting date, he said the Penang government did not appear to have penalised the SPV.

He said when the project was awarded, a statement was issued stating that shareholders of the SPV consortium are China Railway Construction Corporation (CRCC), Beijing Urban Construction Group (BUCG), Zenith Construction, Juteras Sdn Bhd and Sri Tinggi Sdn Bhd.

“But today, CRCC, BUCG and Sri Tinggi were no longer listed as shareholders while Juteras Sdn Bhd is listed as winding up – leaving only one (Zenith Construction) out of the four shareholders in the agreement.

“Despite a material change of the financial and technical strength promised during the award and what it is now, the Penang government still does not appear to want to cancel the project or penalise the SPV,” he said.

“Even five years after the contract was awarded, the SPV still only has paid-up capital of RM26.5mil – way below the RM381mil minimum paid-up capital required by the Penang government to deliver the project.

“Meanwhile, the SPV is on course to make billions in two property projects valued at RM800mil and RM15bil respectively,” he said.

Meanwhile, Barisan Nasional Strategic Communications deputy director Datuk Eric See-To said the agreement shown to the media by Penang Chief Minister Lim Guan Eng was different from the one MCA deputy president Datuk Seri Dr Wee Ka Siong said was not stamped.

The agreement shown by Lim in a press conference on Friday was between the Penang state government with Consortium Zenith-BUCG; and not between the state and CRCC.

Previously, the Penang state government had shown a copy of a letter of support from the CRCC to prove that it is a party to the SPV awarded to undertake the undersea tunnel project.

On Tuesday, Dr Wee’s statement noted that the Acknowledgement of Commitment signed by the state government with CRCC was not a legally binding document and was hence not stamped.


Related Link:


Penang has enough roads and linkages, say activists - Nation


I was referring to three paired road projects, says Guan Eng - Nation ...



Ti slams Penang govt over lack of transparency - Nation



Related Posts


Cracks at Tanjung Bungah site began in June, Commissioner of Inquiry told Expert panel: (From right) Yeo, Dr Gue and Prof Ramli arr...
Filepic: PenangPropertyTalk Did the Penang Govt do a "bait and switch" on the Penang people? That was the question pose...
Behind BJ Cove houses at Lintang Bukit Jambul 1 is an IJM Trehaus Project.  Approximate Coordinates : 5°20'38.47"N,100°16'...