The Sustainability of Post-crisis Management on Flooding Prevention

The climate change has in the past decades given more extreme rain events, both in terms of intensity and duration, and recurring storm related sea-level rises happen these years almost annually according to different weather cycles around the World. The public policies and management of these events and the initiatives taken to prevent the damages from them have changed during these few decades mainly because of the recession following the financial crisis in 2007/2008. Before the financial crisis, municipalities and their water companies built large capacity basins in order to store stormwater masses in the sewer systems. After the crisis, on-ground rainwater management has become the new best management practice trying to prevent extreme water masses from the sewer system. The new use of the landscape; the green spaces as well as the city roads and parking lots for rainwater storage and transportation is claimed to be less costly than sewer/basin solutions. At the same time, costs for coastal security is rising, and small communities are lacking funds for building floodgates and -walls to protect the coastal cities from the sea-level rises. This turn in BMP is happening worldwide in countries and states struggling with extreme water events. Seemingly, it is all initiated from political pressure on minimizing public expenditure in general, and therefore also on infrastructure and security. This chapter reviews the international literature on flooding prevention and its relation to public policies and management and as an example shows the history of climate adaptation in Denmark. With cases from Denmark, the chapter shows that on-ground flooding prevention risk being even costlier than earlier, because the new ex-sewer solutions are not (necessarily) cheaper than traditional sewer systems especially in the highly paved cities, where the problem is most urgent. These findings supports the UNEP 2014 forecasts of tripling the costs for flooding prevention by 2050 compared to earlier estimates from 2010.