Best of BMT - Keeping Samoa Safe

In August 2018, the United Nations Development Programme needed to develop a strategy to help mitigate floods for the Vaisigano River passing through Apia in Samoa. Funded by the Green Climate Fund, the project was vital to assess and manage the floods and drainage in the area.

While different flood management measures had previously been assessed in isolation to one another, a more holistic approach was sorely needed. So when the UN Development Programme turned to us to help address the issue, we were happy to bring our environmental and engineering expertise to bear.

The project faced several challenges from the outset. Not only was the local environment steep, heavily forested and located in a volcanic catchment, but the traditional system of land ownership presented its own unique social challenges for flood mitigation and there was an overall shortage of high-quality data.

Our flood management team rose to the challenge, and using the fast computation provided by our TUFLOW HPC hydraulic modelling software, we were able to assess a wide range of mitigation options to develop an optimal flood mitigation strategy.

As a result of over 8 months of work, we delivered a solution that assessed a range of structural and non-structural flood management options against social, economic and environmental performance outcomes. Our high-resolution flood modelling and mapping of the catchment will provide a clearer picture of how best to mitigate destructive floods and help keep residents safe.

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This article is part of #BestOfBMT 2019, featuring our best projects throughout the year.