Tuvalu Borrow Pits
New Zealand Ministry of Foreign Affairs (MFAT)
Tuvalu, the fourth smallest country in the world, is a remote Pacific nation about 1000 kilometres north of Fiji. As with many countries, people move to the main centres for work, which results in overcrowding and scarcity of land for housing and development.
These housing pressures were exacerbated on Funafuti, Tuvalu’s main atoll, as when the Americans built an airport runway during WWII operations, they had to dig holes (borrow pits) in the atoll surface to obtain sufficient materials for construction. Fast forward seven decades, and the pits were filled with wind-blown rubbish and sea water which was polluted by effluent from leaking septic tanks.
Not only did these holes create a health hazard and an eyesore, they reduced the atoll’s available land area. Residents had resorted to building stilt houses within the pits because of the land shortage.
The deceptively simple civil engineering project was made complex and unique because of its remote location, lack of resources, environmental concerns, multi-level development objectives, the possibility of finding unexploded ordinance from the war, land-ownership and cultural sensitivities.
Although not the first coral-reef dredging project in the Pacific, the idea of dredging within pristine coral environments is judged to be a high risk operation. To allay these concerns, Calibre spent significant time in the planning and consultant phase of the project. This enabled us to establish appropriate environmental and social management controls, create the most suitable low-impact design method to dredge fill from the lagoon, and ensure the design was locally appropriate and sustainable in the long-term.
The project exceeded all development objectives.
Before and after borrow pit filling.
Filling the borrow pots has enhanced the living standards of the Funafuti community and reduced the risk of water-borne disease and mosquitos, significantly reducing the incidence of dengue fever and improving the overall health and well-being for those living in and around the pits.
The raised land levels provide increased resilience against the effects of climate change and sea level rise and provide additional land for building and other community recreational uses.
The borrow pit project was recognised by Engineering New Zealand with a Gold Award and was described as an outstanding application of innovative thinking to develop solutions outside the box to help Tuvalu battle climate change and sea level rise, and prepare for an uncertain future.