The risk of extreme future flooding events in major Vietnamese metropolis Ho Chi Minh City could increase by up to 10 times by 2050, resulting in immense economic and infrastructural damage, according to a new study by an international consulting firm.
The report by McKinsey Global Institute provides a snapshot of flooding in the fast-expanding city by analysing hydrological simulations, land use maps, infrastructure databases and damage curves. The future, without action, will become increasingly difficult to manage, it concludes.
As time passes and Ho Chi Minh City grows at a rapid pace, the impacts will increase exponentially. A flood with the same probability as today in 30 years’ time will cause triple the amount of infrastructure damage and 20 times the knock-on effects.
Major projects currently underway, including the underground metro system, as well as new power plants, wastewater processing plants, data centres and a new airport, would be valuable assets highly exposed to future risk.
If climate change was not mitigated and sea level rises hit 180cm by the end of the century – as forecast under a worst-case scenario – a once in a century flood would inundate two-thirds of the entire city.
Mangroves to the rescue?
The study agrees that revising real estate codes would help. But greater benefits are likely from restoring nature itself, particularly the extensive mangrove system close to Ho Chi Minh City.
Mangroves currently offer significant protection from more extreme events, reducing the height of storm surge by 20 per cent or more for every 100 metres of forest, the report outlines, noting that the city has made substantial achievements in replanting over the past three decades.