Limiting the extent the extreme is transformed into catastrophic

This blog is written by one of the programme’s Swedish experts providing advisory services to local experts. His name is Peter M. Rudberg and he is a water governance researcher with foci that include climate change adaptation, hydropower production and drought mitigation.

Tragic October floodings

The month of October started with extreme precipitation (in this case rainfall) that led to the catastrophic flooding and landslides in BiH and ended with another extreme event that caused catastrophic flooding in Spain. Unfortunately, the continued emissions of greenhouse gases, causing climate change, means that extreme precipitation events will become more frequent and intense. We are therefore entering a period with higher risk of intense flooding and related natural hazards that can cause significant loss of lives and livelihoods. The highest part of the death toll from the flooding in BiH, however, came from the collapse of a quarry above Donja Jablanica that buried parts of the town in rubble. In Spain there are indications that delays in activating the early warning system contributed to the high level of casualties from the floods. This early insight points towards the importance of national or regional early warning systems and risk management in planning to live with floods and minimizing catastrophic effects from extreme rainfall events.

Living with floods

In 2021 BiH published their National Adaptation Plan to facilitate and advance the country’s climate change adaptation planning. One of the proposed measures in the plan includes studying the possibilities of the ‘living with floods’ concept in BiH. The living with floods concept is part of a wider shift in flood risk management that puts more emphasis on creating societies that are more resilient - capable of withstanding and recovering from flooding – rather than focusing primarily on building the physical structures that are meant to limit the risk of flooding. At a municipal level there are many risk management requirements that fall outside the scope of municipal management. The quarry that collapsed in Donja Jablanica, for example, appears to have operated without a concession for exploitation. Early warning systems are furthermore a responsibility that usually lie primarily at a national level. There are good examples of effective early warning systems, including in Bangladesh, that limit human casualties from floods and extreme weather events. 

The municipality is however responsible for the planning of its territory, including existing urban areas and future developments which can be more or less aligned with flood, and related, risks. Planning to live with floods is both a local and a basin wide effort. The water agency of the southeast of France (Agence de l’eau Rhône Méditerranée Corse) has created a short information film about managing extreme precipitation that highlights key management actions. In urban areas, river embankments should be pushed back to widen the river corridor. On a municipal and regional scale, rivers should be allowed to meander and connected to its natural floodplains. Such actions provide more space for water and the river with areas that can be flooded during extreme rainfall events without causing catastrophic damage. 

Costs of living with floods

In many places, existing housing and infrastructure have been built in natural floodplains and would be negatively affected by pushing back embarquements and widening the river corridor in urban areas. Significant modifications to existing infrastructure can at times be difficult to implement due to technical, economic and political reasons. Although such measures, at times, cannot be discarded to limit the risk of catastrophic flooding, there are also steps with limited direct economic costs that can be implemented. One such key measure is within the realm of municipal planning; to limit new urban or peri-urban developments that are in natural floodplains or require significant modifications to existing rivers. The implementation of such planning policies ensures that new risks and vulnerabilities are not created by building new infrastructure in areas unsuitable from a flood risk perspective. The possibilities of implementing such a policy are improved if accompanied by certain risk communication. A communication that clarifies that the risks of extreme events such as flooding can never be completely eliminated and that the goal should be limiting the extent the extreme is transformed into catastrophic in terms of loss of human lives and essential infrastructure. Learning to live with floods represents a sustainable and economic option in the long-run, compared to trying to minimize the risk of flooding, a risk that can never be eliminated and also a risk that is increasing with climate change.