Tips for successful flood control
What makes flood control projects successful? This is the question answered in a new study by the University of Bern’s Mobiliar Lab for Natural Risks. Its findings? Among other things, all stakeholders need to be involved as early as possible. In addition, popular acceptance of projects is more likely if recreation areas are created.
Wide range of success factors
The analysis of the success factors gives a mixed picture – as successful flood control projects should do more than protect residential buildings and infrastructure from the rising waters. When possible, they also have to suit all of the affected populations. In addition to satisfying homeowners in the danger zones, projects need to be accepted by the fire brigade and civil defence forces, and by any farmers who might have to cede their land for the sake of protective structures. Acceptance also increases if environmental organizations or those not directly affected see a benefit in the protection measures.
According to the study, projects find wide acceptance when the following points are taken into consideration. All actors – including the specialists – should be involved as early as possible. It is important to coordinate the measures on the town borders, ideally as a part of regional planning. Flood control projects are also perceived positively if they have an additional benefit. The restoration of a river section isn’t just a win for the environment; it provides recreational space, too. Also decisive for success: open communication and an exchange with municipalities that have already implemented similar projects.
Wanted: anticipatory planning
In the long term, flood control projects will be judged by how well they help prevent damage. The analysis of the Mobiliar Lab found that in this regard, protective structures have not only positive effects. According to the study, they gave a sense of security. If there was no flooding, risk awareness declined and there was the threat of the “careless use of the floodable area” – for example, when there is more building in a danger zone. In this context, researchers speak of a necessary “control of spatiotemporal risk development”. In other words, flood control projects cannot become an invitation to build – because if there actually is a flood, then costly buildings will be at an ever-increasing risk of damage. “If the concentration of valuable property increases in protected areas, then the potential for damage and risk increases, not least for the insurance companies,” points out Luzius Thomi.
Swiss flood protection still lacks such forward-thinking considerations. Projects are often implemented without a view of future risks, but rather as an immediate response to previous floods. Flooding was the trigger for 80% of the projects studied by the Mobiliar Lab. Or in the words of one of the community representatives surveyed for the study: “Above the village, two or three storms converged. All the water came down at the same time and devastated the whole village. It was clear that something had to be done.”