Houseboats built to survive floods

The indigenous Manobo people live and thrive on houseboats in the vast wetlands of the Philippines, despite dozens of storms and floods each year. What can we learn from that?

Marites Babanto, leader of the Manobo indigenous community in the southern Philippines, still remembers the moment when a terrible storm hit her village in 2012. The rains caused water levels to rise in the Agusan marshes, a wetland region with rivers, lakes and swamps. Babantu and his community live at a height of 10 meters, which is equivalent to a three-story house. But the villagers' houses, instead of submerging, floated thanks to an ingenious ancient technique that kept them afloat.

"Our community has never experienced a storm like this. The winds howled so hard and the rain poured for hours. We gathered everyone to hide inside the floating tribal hall hoping for the best.”said Babantu, remembering that catastrophe.

The storm, known as Typhoon Bopha or Typhoon Pablo, killed nearly 2.000 people and caused widespread damage when it devastated the Philippines in 2012. However, when Babantu and his neighbors assessed the impact on their community, they found that their homes were still intact. Built on floating platforms as a traditional way of coping with periodic flooding and storms, this method has proven resilient even in the face of this particularly strong storm.

The floating houses of the Manobo people, along with many other inventions and methods that allow them to live in the transition zone between land and water, are attracting increasing interest from researchers who see them as important lessons for others. societies in extreme climatic situations.

A world of houseboats

About 290.000 members of the Manobo community live in the Agusan swamp, life revolves around wetlands and water. There are no roads or sidewalks. Instead, houses and residential areas are connected by rivers and lakes.

While Babantu is away on business, he paddles around his houseboat neighborhood in a baroto, a traditional wooden canoe. He passes family homes, tribal halls, schools, churches and animal farms, all floating. He canoes the Sacred Lake to the heart of the Agusan Swamp, the largest and most pristine freshwater wetland in the Philippines, and offers a prayer to the swamp. He then rows back to his small floating barn to feed the ducks, chickens and pigs. He then put his house in order, washed clothes on the porch and took his nephews and nieces to school in their small barotos.

Floating communities are a practical solution to living in wetlands with meandering rivers and seasonal lakes, and no dry, solid land to build on.

Flooding is an annual phenomenon in swamp communities, and monsoon rains from December to March cause water levels to rise. In the dry season, the water recedes. To adapt to these extreme fluctuations, communities traditionally build one- or two-story houses on raft-shaped foundations made of bamboo and balsa wood. Wood floats thanks to natural air pockets. The platforms are secured with strong ropes and vines wrapped around bangkal trees, a native wetland plant that grows in flooded lakes and swamps.

"As long as these trees remain, our houseboats will be able to thrive [despite] the flood" says Babanto.
In fact, he fears strong winds more than the increasingly frequent floods and it is because he sees a potential benefit in them: "The more water we have, the more fish we can catch."

As scientists warn that climate change is making storms and floods more frequent, more intense and more powerful, the potential benefits of houseboats are attracting interest beyond the traditional communities that invented the system. In archipelagic countries like the Philippines and Indonesia, houseboats are seen as a viable solution for urban communities threatened by flooding and rising sea levels. Countries such as the Netherlands and New Zealand have developed modern houseboats, reinforced with steel and concrete, to adapt to fluctuating water levels and catastrophic winds. 

Living between land and water

The community's houseboats are built on raft-like platforms made of bamboo and balsa wood, and tied to native Bangkal trees (Credit: Gab Mejia)

Francisca Mejía is a Filipino architect and urban design researcher at Delft University of Technology (TU Delft) in the Netherlands. She believes the world needs to pay more attention to indigenous cultures like the Manobo people when it comes to combating climate change and its effects. However, she cautions that indigenous inventions, such as the houseboat, can only be fully understood as part of a broader belief system related to the conservation of nature and the lands of indigenous communities.

"In the worldviews of indigenous peoples there is already a backbone of attention, necessary today in the climate crisis"he says. This care has allowed them toprevail for millennia", Add.

Furthermore, it emphasizes that it is not just specific materials or techniques that make houseboats resilient but also the fundamental way in which the Manobo people and other indigenous peoples of the Philippines approach designing in harmony with their environment.

"Extreme climate phenomena such as floods, storms and now droughts have also evolved in their ways of building," says Mejía. "But the fundamental 'design principles' of these remain the same." "This includes the use of local renewable materials, dynamic and flexible wooden structures that can bend and float to adapt to natural elements, as well as design traditions," she said. "Design and create homes together, as a community."

She describes how the resulting structure of these houseboats adapts to nature in several ways: the sloping roof allows water to drain and cool the house during the warmer months; the floating system allows the entire house to float and sink in the water and can be moved to another part of the swamp if necessary; During more stable weather seasons, they join their homes together to keep the community safe.

The main central structure is "made of bamboo or endemic wood," he said, while the roof, walls and ceilings are usually made of nipa, rattan or intertwined palm leaves. In addition to being durable and biodegradable once discarded, “They can also be easily repaired because they grow locally in their immediate environment"He explains.

The floating communities are part of the Agusan Marshes Wildlife Sanctuary, a reserve of about 14.800 hectares (36.600 acres) with wetlands, peatlands and 59 lakes, located in central Mindanao, the second largest island in the Philippines. This area contains at least 15% of the total freshwater of the Philippines.

Its ability to absorb floodwaters, which fill lakes and are absorbed by spongy soil, is also of crucial importance in the Philippines, which is hit by an average of 20 major storms, usually accompanied by flooding, each year.

For Manobo and other local swamp communities, fishing is an important source of livelihood and is also linked to cultural and spiritual practices that respect the ecosystem and their place in it. They honor the wetland creatures around them with blessings, songs and prayers.

"Saltwater crocodiles, freshwater fish, and migratory birds were the original inhabitants of the swamp, just like our ancestors. Our spirits and gods depend on these waters"explains Datu Durango, tribal chief of the Manobo ancestral region of Lake Benoni deep in the swamp.

Tradition and change

Houseboats, chapels and animal pens in the marshes are built on modular rafts that adapt to the rise and fall of the water (Credit: Gab Mejía)

Fishermen wake up before dawn and sail their barotos, or gas-powered boats, to the deepest parts of the lake to fish and inspect barriers made of woven nets. They bring enough fish to feed their families and share the surplus with neighbors or sell it at the fish market.

This community practice and form of traditional fishing and aquaculture are similar to methods found in other indigenous communities in the Philippines, such as the Tboli indigenous people of Lake Sebu or the Sama indigenous people of the Sulu archipelago.

Sustainability is at the heart of some of these activities, although the community has also experimented with newer and sometimes less sustainable activities. For example, the Manobo have traditionally used methods such as fishing with their bare hands, focusing only on the largest fish and allowing their numbers to remain stable. However, some newer methods, such as nets, catch smaller fish, compared to older, more sustainable methods. Likewise, the traditional time to harvest edible water lilies is during the flood season, when the plant reaches its maximum growth to ensure that the general population is not in danger.

Overall, the intricate web of fishing, housing and wetland-based environmental management has remained remarkably intact, says Ivan Henares, a cultural policy researcher and assistant professor at the Asian Tourism Institute at the University of the Philippines, Diliman.

"This awareness [of their environment], together with their confidence in their own indigenous knowledge and practices [...] has ensured the continued survival of the Agusan Manobo for a long time" says Henares, who is also secretary general of the National Commission for UNESCO of the Philippines and has worked with the Manobo community for a decade.

However, while their houseboats have weathered storms and floods, the community is not immune to the broader consequences of global warming. Henares and other researchers have highlighted threats such as prolonged drought, while the demand for Palm oil has caused peatlands to be drained and converted into agricultural land. Additionally, researchers say poaching timber logging threatens endemic and endangered tree species. They also expressed concern about violence against those fighting to protect wetlands, noting the murder of an environmental official by poaching timber loggers in November 2020.

Michael Sapakagan is the head of the Municipal Disaster Risk Reduction and Management Office in Talacogon, one of the six municipalities in the Agusan Swamp. He said the Manobos were able to adapt and resist floods long before local offices like his were established. And he added: "But only recently have there been unusual changes in the timing of flooding and the frequency of severe wetland storms has increased amid this environmental crisis.".

In recent years, the Manobo people, whose existence depends entirely on water, have faced another growing threat: water scarcity. Drought caused by extreme heat can make it difficult to cross tributaries and routes to nearby floating communities and inland areas, where large fish markets, farmland and higher education facilities are located.

Datu Boyet Reyes, who served for more than 25 years as chief of the Manobo tribe at Panlabuhan Lake in the Agusan Swamp, witnessed how his community adapted to the changing landscape. He said helping communities confront and solve these challenges starts with recognizing the skills and lifestyles that helped them survive in the long term. He also urged non-Manbo people to think about the use of their own resources and how that could affect indigenous communities.

"We need to be respected and included, because the houses that you (non-Manobo) continue to build still come from the same soil, trees and waters that we protect"says Boyet Reyes."If we find ways to help and protect our waters, this water will also find ways to help us. It's their nature"After all, he says, that is the meaning of the name of the swampy area,"Agusan": means "where the water flows".

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