As temperatures rises so does the risk of flooding. The escalating events are leaving communities battling devastation and seeking sustainable solutions.
Written by Unn Madsen
In 2023 the United Nation released a report called ‘The Sustainable Development Goals’ which is a rescue plan not only for people but the planet as well. One of these goals is to take urgent action to combat climate changes and its impact. According to the report due to increased temperature the rate of sea-level rise has doubled in the last 10 years which not only increase the risk of flooding from the seaside but also increase extreme weather happenings and flooding from above.
This is a threat to highly vulnerable regions that experience 15 times higher mortality rates from disasters compared to low vulnerability regions.
To understand how climate changes impact sea levels it is important to know what rising temperatures does to water. Jørgen Eivind Olesen, professor at Aarhus University explains:
“Global mean sea levels rise permanently for 2 reasons. Water expands when it gets warmer and then it takes up more space and the sea level rises. The other reason is the melting ice from Antarctica and Greenland that also contributes to more water in the oceans.”
But flooding is not only a problem for people near the coast. The rising temperature are changing the weather as well:
“With rising temperatures comes more water, energy and windspeed in the atmosphere which leads to more powerful storms and extreme weather” says Jørgen Eivind Olesen.
Although flooding often is connected to extreme water masses coming from the ocean, flooding is also to be found due to extreme rainfall, evaporation that travels from sea to land, overload of the sewage systems or water travelling from mountainsides to valleys.
Drowning Denmark
The Danish Coastal Authority which is a part of the Ministry of the Environment has pointed out in 2020, 14 areas in Denmark that are in risk of flooding, one of these areas are an inlet town called Vejle with 120.000 residents.
“We are placed an incredibly beautiful place but also a challenging place because we are placed in an inlet valley with steep slopes with risk of water runoff that influences the city quite a lot and adding to that the rising groundwater makes water a challenge for us.” Says Søren Peschardt, Chairman of climate nature and environment committee and member of The Social Democratic Party.
As 1 of 14 areas pointed out by the Danish Coastal Authority in 2020 Søren Peschardt hoped that as an announced risk area initiatives by the state would follow but that is not the case according to Søren Peschardt:
“We only feel pointing fingers and laughs and not the help we need to take care of our values which in the end also are Denmark’s values.”
But the storm surge exposed valley inlet and rising waters is not the only problem. Running through town is 3 rivers which are causing its own problems. Climate coordinator since 2011 Ulla Pia Geersten explains:
“Vejle downtown is challenged by not only storm surge and global mean sea levels but also catchment areas from the rivers running through town.”
80 cm water
Homeowner Emil Filsø and his family are no strangers to these problems. May 23rd 2014 a stormy and rainy night results in shortage of power. In attempt to find the source Emil looks from the 1st floor down the stairwell to the basement and sees 80 cm water accumulated at the bottom of the stairs. To get fully aware he steps outside the house just to see everything is flooding outside as well. Their cars descent ramp is fully flooded, and the water pressure has pushed in some of the garage door and left their car hanging under the garage rooftop floating on the water.
Further into the basement everything is ripped out of the wall and stuff that belongs in there are found in the garage and the other way around. But what hurt the most are his late parents’ belongings:
“Everything went from inheritance to trash” tells a clearly touched Emil Filsø.
Emil Filsø and the entire street has not only received huge amounts of water from the surrounding hills but because of their location the sewage system has not been able to let the water and the catchment areas out the correct way which leaves Emil Filsø not only with a flooded house but also with a bottom layer of mud.
100-year event
3 months later another torrential rain hits and despite exclamations towards municipality and the local sewer company about mud clogged sewage systems yet again the rain makes the sewage burst out with mud and sewage water.
As a precaution Emil Filsø asks municipality what to do in case of a similar happening but the only thing he is told is not to worry because a case like this is a 100-year event.
2 years later in 2016 an intense rainfall causes a close by railway to collapse that worked as a dam between the water travelling from the mountainsides and Emil Filsøs neighborhood.
“As the railway burst, 100 meter of shards tumbles over the following gardens and then comes the water as a tidal wave.”
Luckily the renovations 2 years earlier makes the event not as damaging as before but still leaves the family feeling extremely frustrated and not heard by the relevant authorities and leaves Emil Filsø with a stress related illness.
Already in 2016 Emil and Elsebeth Filsø wanted to sell their house and even though they spent almost 900.000 Danish kroner on their former property to make sure it could resist its vulnerable location it was not sold until 2020.
What are we doing?
Other than the already existing projects new choices of measures are already in motion starting with the most difficult:
“The storm surge is the most challenging, because it is the biggest threat when it comes to value loss and general risks.” Climate coordinator Ulla Pia Geertsen explains.
To secure against storm surge it will require embankments from one side of the inlet to the other:
“It is a huge job. We are doing it, but it is a ton of work” tells chairman of climate nature and environment committee Søren Peschardt.
As of now a project called ‘Membranen’ is in motion which are going to integrate water more than fighting it. This will allow water to enter without damaging. It is a project supported by business association RealDania. It started in January 2024 and are expected done in 2027.
The city is also working on multiple dam plants which purpose is to storage and delay rainwater temporarily and let it out whenever the water once again can run smoothly. This amongst tools as locks and pumping systems are effective ways to keep control of all the water issues but it is far from perfect, especially considering the rapidly changing climate events:
“As of now we are able to handle a 20-year event but what we are working on are to handle a 100-year event.” Says Climate coordinator Ulla Pia Geertsen.
Talk about the future
What is the most effective way to prevent flooding?
According to Professor Jørgen Eivind Olesen at Aarhus Univeristy the most effective way to prevent flooding is simply not to build too close to the coast. Emil Filsø agrees:
“We lived on an old river. I mean, it is a river. It is just us people that has taken over areas that we maybe shouldn’t have.”
To Ulla Pia Geertsen the location is not a problem as long as people remember to make climate adaptive planning when it comes to building. She says:
“We must be aware of climate changes when we expand building areas otherwise, we will not succeed. But it is a difficult task.”
To Emil Filsø it is a task not only for municipality but for everybody:
“It is the state and municipalities but the residents as well. We need to make it our problem and not just let it be the next properties problem. But there is a long way. A very long way.”