Building with Nature: scaling solutions to flood threats across Asia

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With the impacts of climate change growing, Asia’s coastal areas are increasingly vulnerable to disasters such as floods, typhoons and tsunamis. In the run up to the UNFCCC COP25 in Madrid next week, Wetlands International Associate Expert, Fred Pearce, explores how ecosystem restoration, through a process of ‘building with nature’, is helping Indonesia become a pioneer in coastal resilience.

It is a long drive to the village of Timbulsloko on the northern shores of Java, Indonesia’s most populous island.  There is water either side of a causeway that stretches for five kilometres through flooded fields, passed crumbling houses reached by rickety walkways, and a village cemetery that is largely washed away.

In the meeting hall facing onto the ocean, Slamet, a fishermen, told how the village had changed.   “I grew up in the 1960s when the sea was more than a mile away.  Then the flooding began,” he said. A lethal combination of rising sea levels, lost coastal mangroves and sinking land caused by groundwater abstraction in the nearby city of Semarang had allowed the Java Sea to invade.  Two villages had entirely disappeared.  Some 20 square kilometres of the once-prosperous rice-growing district of Demak had been inundated.

But the villagers were fighting back.  “We are not leaving,” said Slamet. “This is our home and, God willing, we plan to stay.”

For several years the people of Timbulsloko and eight other villages along this beleaguered coast have been working with their local and national governments, along with Dutch engineers and environmentalists, to restore riverine mangroves along aquaculture ponds, and to line the shore with permeable barriers made of brushwood that aim to halt erosion and restored mud banks where mangroves will regrow naturally.

While the villagers are focussed on survival and the recovery of their land, their partners believe that the work is an inspiring example of adapting to climate change that will be applicable in the coming decades across Southeast Asia and beyond.  They call it Building with Nature.

Indonesia is an archipelago of islands with thousands of kilometres of low-lying coast, once fringed by mangroves that absorbed the ferocity of storms and prevented erosion by the waves.  But Java has lost 78 per cent of its mangroves, exposing coastal communities, ports and cities, says Abdul Muhari formerly of the Ministry of Maritime Affairs and Fisheries, a project partner, and now head of early warning at the government’s National Disaster Management Authority.

After tentative beginnings in Demak, his government has embraced Building with Nature and is scaling up rapidly.  Almost 30 kilometres of permeable barriers have been put in place along the Java coast and on the islands of Lombok and Sulawesi, where there is a plan to restore mangroves to protect Palu Bay, after a damaging tsunami in 2018.

Restoring mangroves is about much more than planting, says Muhari.  Too often, the saplings get washed away.  What is vital he says is restoring their habitat, by encouraging the accumulation of stable sediment.  “We have proved that permeable structures are capable of restoring coastal ecosystems, and such an approach should be regionally introduced and upscaled.”  Using such nature-based solutions, Muhari hopes to restore more than a thousand hectares of coastal areas within five years.

For western environmentalists, “nature-based solutions” is an increasingly popular term.  It is often seen primarily as a way to fight climate change by protecting and restoring coastal ecosystems that soak up carbon dioxide.  They call it “blue carbon”, and it will form an important part of the agenda at the UN climate negotiations in Madrid in December.

But Building with Nature is less about mitigating climate change and more about climate adaptation, says Fokko van der Goot, programme manager at Ecoshape, a public-private platform set up by Dutch engineers and environmentalists to promote the concept.  “It is a design philosophy that integrates the services that nature provides into civil engineering practice.”  It allows engineers to work with nature rather than against it, and sees community involvement as central.

Deltas and coastlines, which are home to hundreds of millions of people in Asia, when starved of sediment and lacking vegetation are wide open to erosion and inundation by rising tides.  But if they can be given plentiful supplies of sediment and retain their vegetation, they can both rebuff the waves and even rise up naturally as the seas rise.  Building with Nature aims enhancing natural processes to give them the best chance of achieving that.

The Dutch origins of Building with Nature are strong.  The environment group most heavily involved is the global network Wetlands International, a leading partner in Ecoshape.  And Dutch dredging companies such as Boskalis have brought ideas first developed on the low-lying Dutch coastline.

But the Indonesian government has embraced the philosophy.  Since 2012, it has adopted the idea of using nature to restore beaches, reduce damage from large storms and even tsunamis to some extent, and adapt to changing river flows and rising tides.  Increasingly, it is acting as a showcase for the approach.

At a meeting in the Netherlands in July 2019, organised by the Indonesian government, with Wetlands International, Ecoshape and the Dutch-based convening body the Global Centre on Adaptation, governments from across Asia met to discuss a series of future projects that could incorporate Building for Nature.  One example was restoring wetlands in coastal Kerala in southwest India, which has suffered from tropical storms in backwaters that attract millions of tourists.  Rather than trying to drain the wetlands, the idea is to use them as a natural reservoir for the floodwaters.

Enthusiasts say such projects offer a triple win for nature, communities and economies. “Projects meet local needs, while boosting benefits such as fisheries, carbon sequestration, recreation and biodiversity,” says Yus Rusila Noor, head of the Building with Nature programme at Wetlands International Indonesia.  “The aim is to transform the civil engineering sector in Asia by promoting nature-based solutions.”

There are barriers.  Bringing environment and engineering experts and administrators together is not easy.  Their outlooks and expectations can be very different.  And while engineering solutions usually have measured outcomes, nature can be less predictable. But there is growing recognition of the value of building with nature,” says Pieter van Eijk, programme head for deltas and coasts at Wetlands International.

Indonesia also recognises Hybrid Engineering in various of its policies and strategies, including in its the mid-term development plan. This is creating an enabling environment for replication at scale.

Funding agencies are getting on board.  Isao Endo of the Asia Development Bank says: “Investing in natural capital can help in receiving multiple benefits such as restoring critical ecosystems, improving climate and disaster resilience and creating liveable cities.”

In October 2020, the Netherlands hosts a Climate Action Summit, which is a crucial next step for the Building with Nature Consortium.  The formal target is to leverage funding so that Building with Nature approaches are adopted in 15 landscapes in five countries, benefiting 10 million people by 2030.  But it is bigger than that. The ultimate aim is continent-wide upscaling, says van Eijk, by 2030 to have Building with Nature as a mainstream approach for climate adaptation in coastal and delta areas across Asia. Its task is nothing less than to future-proof the cities, coasts and rivers of Asia.

An important part of the upscaling work is training the next generation of engineers, says Femke Tonneijck, programme manager for coastal wetlands at Wetlands International.  “Thousands of engineering students are now being taught Building with Nature methods and they are taken them to their future employers.”

Equally important, is involving local communities at every stage — as policymakers, actors, beneficiaries and ultimately owners of the structures and actions.   That is central to the Building with Nature philosophy.

In Timbulsloko and its neighbours, the communities were not paid for their labour in erecting the permeable barriers.  Instead, they received loans for development projects using coastal resources, such as improving the productivity of their fish ponds and providing facilities for tourists.  And they were given places at coastal field schools, where they learned how to increase income from their fish ponds, while at the same time protecting coastlines, often by restoring mangroves around the ponds along the coast and rivers.

“Communities have started to recognize the importance of mangrove conservation and have allocated land along the coast and rivers for mangrove restoration,” says van Eijk.  Independent studies have shown that the 400 hectares of ponds that have adopted best practice are seeing tripled yields and doubled incomes.  “Thanks to Building with Nature, we have been able to increase the quality of our shrimp,” said Djaelani in Purworejo village, Java.

While often seen as best suited for protecting rural landscapes, Building with Nature can be vital for urban environments too.  Just down the coast from Timbulsloko stands the booming city of Semarang.  It is a menace to itself.  New industries get water by pumping from the muddy sediments beneath the city.  The result is massive land subsidence, both in the city and along the coast.  It threatens the success of the mangrove restoration in front of villages such as Timbulsloko.

Some of the organizations involved with mangrove restoration in the villages have been advising on how to use Building with Nature methods to remake the city’s hydrology.  Proposals include switching to surface water supplies to allow an end to groundwater pumping, as well as better management of storm water after rains, and the integration of a planned coastal road into a scheme to protect the coastline with a 2000-hectare mangrove and fishing park.

The same programme, known as Water as Leverage, is targeting solutions to flood problems in two other major cities in the region, Khulna on the Ganges delta in Bangladesh and Chennai in eastern India.

What started seven years ago as an emergency operation to save a handful of villages in northern Java is growing into a philosophy for using nature to save hundreds of millions of people from the threats of climate change and extreme weather across Asia.

Back in the villages of Demak, they say the method works. Behind permeable structures extensive sediments have accumulated and mangrove seedlings had started to emerge everywhere. Communities have allocated land along the coast and rivers for mangrove restoration and the permeable structures have now been handed over to them to maintain, with local-government finance.  While land subsidence has limited mangrove restoration in villages close to Semarang, “the permeable structures have stopped erosion, and that is a big gain for the villagers,” says Tonneijck, “and promising for other villages along Northern Java’s delta shorelines where in the long run millions of people may be affected by coastal erosion.”

By Fred Pearce (joint author of the publication ‘Water Lands’ – coming soon)

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