The DANA disaster in Valencia,the subsequent heavy rains in Barcelona after a couple of days and even the recent flooding of Cadaqués have put us on notice. They are not the first. The progressive disappearance of the Catalan beaches and the chronic drought in which Catalonia has settled convince us of a reality: climate change has already arrived.
We are getting used to look at the sky with suspicion and the rivers with the distrust of not knowing if its appearance is real or just the premonition of threat. That is why we are now looking for tools such as the ‘Sistema Nacional de Cartografía de Zonas Inundables’, a free, interactive map from the Ministry for Ecological Transition showing which areas are at risk of flooding in the country in the event of floods or rising sea levels.
The tool is not complicated but not very intuitive to use, so we tell you step by step how to do it to find out if you live in a flood zone in Barcelona.
How the flood zone map works
As we said,the use of this map is not complicated, but counterintuitive. In essence, this cartographic viewer allows you to study the location, orography and urbanism of the areas to add and superimpose by layers the areas flooded by rivers or seas in different time frame.
In this field, flood probabilities are measured by number of floods every few years. That is, if an area is low risk, it is estimated that it can flood once every 500 years, while, on the other hand, an area that floods every ten years or less is an extreme risk area.
Thus, if we go to the Besós riverbank, we can see the risk of flooding of the territory adjacent to the river every 500 years (low risk), every 100 years (medium risk), every 50 years (high risk) or every 10 years (extreme risk).
Step by step to use the map
We give you the step by step to find out your own data.
- To start, you must enter this platform. In the menu on the left side of the screen you will have to click on the section dhp zi, the acronym for “public hydraulic domain” and “floodable areas”. Here you can search for the different watercourses by name or location.
- In the menu above, select the “services tree” section , where a drop-down menu will appear with options, including flood zones with different time periods (10, 100 and 500 years) and, in general, areas at risk or floodable due to river floods or sea level rise.
- In this section we are interested in options such as ” Mapping of flood zones (ZI) of fluvial origin”, ” Mapping of flood zones (ZI) of marine origin” or “Areas of significant potential flood risk”.
- From here,you can select the zones, the hazard maps or the extent of the flood zones, and choose them according to the flood risk.
- To delete a layer and change it to another, go back to the top menu, select “Table of contents”, and delete the layers that have been added.
To make it perfectly clear to you, we have made a video where we explain step by step how to use the tool.
What are the flood zones in Barcelona?
In Barcelona you can make a search for both flood zones by rivers or by the sea. If we activate both parameters (‘Cartografía de zonas inundables (ZI) de origen fluvial’, ‘Cartografía de zonas inundables (ZI) de origen marino’) with medium risk (floods every 100 years) we can have an approximate map of the aspect that the City of Barcelona will have in the near future.
Once these layers have been activated, we can see that the banks of the Besós and Llobregat rivers are completely overflowed. In the event of flooding, their riverbeds rise until they occupy the promenades that now border them, and in several areas the water overflows to the point of flooding the surrounding towns.
Farewell to the neighborhoods and cities of the Besós and Llobregat rivers.
In the Besós the areas of Sant Adrià, la Mina and the area closest to the Badalona river are flooded, as is Santa Coloma de Gramenet at the height of the Nus de la Trinitat. In the Vallés, large areas of municipalities such as Ripollet, Cerdanyola, Sabadell, Mollet or La Roca del Vallés would also be under water.
The Llobregat side is the most gloomy. The water would recover its place by flooding the entire Llobregat delta, including the airport area, and would reach a good part of the nearby towns such as Prato or Sant Feliu.
If we go up the risk zone, we see that the water would cover the entire Zona Franca, a good part of L’Hospitalet and Sant Joan Despí, while on the Besós side it would cover a good part of the Besós neighborhood.
A city without beaches or Barceloneta
The case of sea level is straightforward. With the same probability, Barcelona will be left without beaches and promenade. In the case of Barceloneta, the sea level will rise until it almost completely occupies the neighborhood and makes it disappear.
In the rest of the promenade , the water will rise up to the coastline, covering the entire promenade of the city and returning the level of the coast to where it was before the city built on top of the sea to gain that space.
15 % of Catalonia lives in a situation of risk
Outside Barcelona, areas such as the Ebro delta (flooded in its entirety), the Tordera delta, areas of the Empordà or the coast of Maresme are other areas that could be greatly affected by possible floods or rising sea levels.
The Catalan Water Agency has detected that 15% of the Catalan territory is flood-prone, and estimates that there are currently more than 700,000 people (9% of the population) living in these areas.
There are 521 municipalities that should have a municipal civil protection plan, but more than half, almost 300 do not have one yet.
You can consult the municipalities that do not have a flood plan in force or drafted in this article. or drafted in this article.
You may be interested in: What Barcelona would look like if it were flooded due to climate change.