Borrow Pit Remediation
New Zealand Ministry of Foreign Affairs (MFAT)
Calibre has helped the island nation of Tuvalu to clean up the Funafuti atoll through filling 10 borrow pits. Sand from the Funafuti Lagoon was dredged to fill the borrow pits which were created during World War Two when the American military ‘borrowed’ earth from some places to construct the island’s runway. The pits had been filled with stagnant water and rubbish and subsequently become a health hazard, reduced environmental resilience and reduced available land by 6%.
This relatively simple civil engineering project was made complex and unique by location, multi-level development objectives, the possibility of finding unexploded ordnance from the war, land ownership and cultural sensitivities.
Being the first coral reef dredging project in the Pacific, significant time was spent in the planning phase to ensure appropriate environmental controls and a detailed project management plan were established. Calibre completed an environmental and social impact assessment and ongoing management plan, determined the most cost effective, low impact design methodology for the dredging of fill, and ensured the design was locally appropriate and sustainable in the long-term. We maintained an onsite presence for six months to ensure all client objectives were met.
Before and after borrow pit filling.
Filling the Borrow Pits has enhanced the living standards for the Funafuti community through reducing the risk of water borne disease and mosquitoes and improving overall health for those living in and around the Borrow Pits.
The raised land levels also provide increased resilience against climate change and future sea level rise and make more land available for building and other community and recreational uses.