It was in 2018, whilst watching a news documentary on Azizakpe, an island fishing community of Ada in the Greater Accra Region of Ghana, that Rhoda Osei-Nkwantabisa (last name pronounced O-s-æ N-quan-ta-be-sah) got the inspiration for her thesis. Then a second year KNUST architecture student, she became fascinated with the story of this town which, over the last two decades, has been subject to floods due to climate change and has lost its economic livelihood. She immediately wanted to step in and change the narrative.
Growing up, Osei-Nkwantabisa, who lived between her grandmother’s residence in Tema, Greater Accra Region and her parents' in Brong Ahafo Region, was struck by the changing landscapes on her road trips to the Brong Ahafo. She recalls the stark differences between the well-planned communities of Tema and other parts of the country, which were less-structured and underserved, and wanting to get involved in the transformation of deprived areas. This interest led her to study architecture.
In 2022, four years on from the time Rhoda got to know about Azizakpe and now in her Architecture design thesis year, she wondered how she could help this community she had fallen in love with. Her response - designing a well-planned Azizakpe that could adapt and thrive with changing seasons and climates.
Azizakpe, which literally translates to Dwarf Town, is over a century old, and is in the estuary of the Volta River where it enters the Atlantic Ocean. Primary vegetation here is coconut groves, mangrove and swamp forests. There are mythical stories about the town's origin, of being founded and inhabited by dwarfs, who gradually got driven out by the depletion of its forests.
Over the past few years, 20 acres, accounting for about a quarter of the total land area of Azizakpe, have been lost to erosion and water submersion due to rising sea levels from climate change. Aquatic life such as river crabs and fishes they depend on for economic gains have been depleted due to destruction of their natural habitats. Dredging of the Volta River by the government about two decades ago to counter Bilharzia has resulted in the ingress of salty sea water onto the island, destroying the coconut tree groves and depriving the locals of their primary sources of income - coconut oil production, basket weaving and broom-making. Additionally, lack of basic infrastructure, along with the disruption of their means of income, have caused most of the residents of Azizakpe to emigrate to other parts of the region.
The remaining residents and some agencies have adapted mechanisms such as small rock sills arranged perpendicular to the river, car tires filled with concrete, sand bags and tubes, and bridges to protect and navigate the flood prone areas at the community scale. Past mangrove restoration projects in the area have been unsustainable as the mangrove trees are harvested and not replanted. At the building scale, residents have used resilient strategies such as building their homes on concrete plinths, and raising the structures on stilts. However, all these solutions have been unsuccessful as the water level continues to rise.
Following her watching the documentary and leading up to her thesis year, Osei-Nkwantabisa made a number of visits to Azizakpe to learn about the environmental challenges plaguing the area and devise cost-effective methods to counter the flooding and erosion problems with her architectural training.
Osei-Nkwantabisa opens her research presentation with the question, "Should islands disappear?". In her thesis text, Osei-Nkwantabisa notes the global uncertainties about the future due to the impact of climate change on communities and livelihoods. She writes: In the past decades, severe flooding in major cities and towns across the globe has resulted in loss of human life, damage to properties and infrastructure, and destruction of crops among others. Coastal cities and island communities are among those facing the highest risks from the impact of climate change due to rising sea levels. Despite their huge tourism potential and economic opportunities, most island communities in Ghana are at risk of being abandoned due to climate crisis and limited investments.
What Osei-Nkwantabisa’s visits to Azizakpe did for her was to open her awareness to the tourism potential of this waterfront community, and to arrive at the proposal of an ecotourist resort to generate income and jobs for the community. By using amphibious architectural techniques in the design of the resort, she deduced that buildings in such harsh environments can become inherently resilient, adapt to rising sea levels, and thrive in the occurrence of floods. Amphibious buildings are structures that rest on the ground, but when floods occur, rise up in their docks and become buoyant.
Prior to settling on this design approach, Osei-Nkwantabisa had done extensive research into coastal defense mechanisms for countering erosion in waterfront areas as alternate solutions. She deduced that typical techniques such as concrete sea defense walls have prohibitive costs for growing economies such as Ghana, and nature-based methods like mangrove swamps, oyster reefs, and rock walls are more financially attainable and resilient solutions to erosion and flooding.
Designing The Resort
In planning the ecotourist resort, the island is graded into three levels of vulnerability to floods and erosion - highly, fairly, and lowly vulnerable. With the south-east and eastern portions of Azizakpe being directly in the path of the sea waves, these areas are demarcated as mangrove wetlands. The research recommends the relocation of residents from these sections to the northern portion of the site, locating the ecotourist resort in the central portion, which is moderately vulnerable to erosion and floods. This is done to create resilience in the vulnerable areas and fully protect the local community in the North.
The design of the resort mimics crab holes, straddling the island from east to west. It is made of 23 one and two-bedroom villas raised on stilts and linked together by elevated walkways sitting within local flora and fauna. On arrival at the docking area on the west, visitors are led on a circular walkway to the reception, which is flanked by a conference room, restaurant and other amenities. Beyond these social nodes, guests are drawn into the enclaves of villas and suites on the east.
The Structures and Materials
For her primary materials, Osei-Nkwantabisa selected mangrove wood. She says, “I needed to find solutions that were cost-effective and mangrove wood is readily available in the community. Since it grows there naturally, it means it is going to be a cost-effective solution and it is going to survive.
Each building is designed with three features for resilience to floods and rising sea levels: stilts from mangrove wood, which raises the building about three meters above ground; a bamboo cage at the base filled with plastic bottle waste for buoyancy; and a bamboo raft also for buoyancy. The stilts are designed to mimic the mangrove roots. She writes in her thesis, “They (the stilts) are anchored to concrete pile foundations and braced together to help ensure that the structures do not shift when the floods come in, and they work together at the same time.” The stilts also have a mechanism that allows them to extend an additional three meters in the event of rising sea levels. If the slide mechanism on the stilts fails, the bamboo cage and raft act as backup ups to ensure the building floats. Other local materials and techniques featured in the design of the buildings include thatch for roofing, woven coconut-leaf mats for walls, and bamboo raft floors. This way the design employs local talent well-versed in the methods for making these.
Beyond the materials and techniques featured in the structures, Osei-Nkwantabisa also proposes sustainable measures to run the resort - solar power, cross ventilation cooling techniques within the spaces, biosand filters for grey water reuse, and composting toilets which would safely discharge effluent into the surrounding water during floods. These are intended to work together to further reduce the carbon footprint and energy usage of the resort.
The resort also features green transportation in the form of solar-powered resort buggies and is generally designed to be pedestrian- and bicycle-friendly.
By employing amphibious architectural techniques using local material and appropriate technology prevalent in an area, Osei-Nkwantabisa postulates through her research that island communities could more easily adapt buildings to changing climates and thrive, build capacity and generate alternative sources of income through tourism for locals.
About Rhoda Osei-Nkwantabisa
Rhoda Osei-Nkwantabisa graduated from KNUST’s Master of Architecture program in 2022, and is currently undergoing her National Service at her alma mater, teaching at the Department of Architecture. Her research was supervised by Dr. Martin Larbi and Arc. Isaac Annor, both lecturers at the department. Osei-Nkwantabisa gratefully acknowledges the support of Mr. Emmanuel Kankam in the construction of the 3D impressions.
Thank you to our guest editor Nana Bonsu Adja-Sai for his feedback on and contributions to this piece.