The financial benefits of flood protection measures such as dykes, dams and flood gates can exceed costs for rebuilding after a disaster by up to ten times, according to a study by Swiss Re Institute.

Economic losses caused by natural catastrophes reached an estimated £218bn in 2023, with £40bn due to floods, according to Swiss Re Institute. Losses are likely to increase as climate change intensifies extreme weather events while rapid urban sprawl has increased asset values in high-risk areas.

Swiss Re Institute has carried out a study comparing economic benefits and cost ratios of selected flood adaptation measures. It says this value can serve as a guideline for investment decisions and help identify the best flood adaptation methods to ensure a community's economic stability, safety and resilience.

Veronica Scotti, chairperson of public sector solutions at Swiss Re, said: “Investments in climate adaptation, such as flood preparedness, not only promote economic stability and create jobs, but also help keep people safe. Yet there is chronic underfunding. It is therefore crucial to create the conditions for private capital to flow into climate adaptation projects and at the same time optimise the use of public funds. Quantifying the benefits of adaptation measures is a key step towards facilitating public-private investment and ultimately closing the huge financing gap.”

The report suggests that grey infrastructure, such as dykes and levees, is highly effective in reducing coastal flood damage. Globally, their benefits can outweigh costs by two to seven times, and even up to ten times in flood-prone areas. The study says that when built to optimal standards, these structures can reduce flood damage by 60%-90%, especially in densely populated regions. In less populated areas, nature-based solutions such as barrier island restoration or foreshore vegetation can be equally effective.

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