#Berlin, a major European capital, relies on a unique water management system where drinking #water is entirely sourced from local #groundwater. In recent years this system faces increasing pressure. Alongside the main factor of climate change, which leads to longer periods of #drought and heavy downpours, the city also must cope with the expected closure of a nearby coal mine by 2038, which has so far supplemented the water levels of the #Spree River.
Ensuring a sustainable water supply for Berlin’s millions of residents, as well as industry and businesses, demands proactive measures. The Berlin Senate has initiated the ‘Masterplan Water’, a comprehensive strategy that includes several measures to safeguard this vital resource.
The European IMPETUS project plays a key role in this by using computer models to simulate various future climate scenarios and their potential impact on Berlin’s water resources. The researchers are analysing the effectiveness of different water management strategies, including adapting to longer periods of drought and phasing out the current artificial water supply to the Spree River.
Discover the complexities of Berlin’s water management system, the challenges it confronts due to climate change and structural shifts, and the science-driven solutions being developed to safeguard its water future.
Would you like to know more about the research of the IMPETUS project? https://www.youtube.com/playlist?list=PLb8wE1rKCAQfiXL8ZkyfJV_qVLPi0HXA4
SOCIAL MEDIA
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
Website: https://climate-impetus.eu
X: https://x.com/climateimpetus
Linkedin: https://www.linkedin.com/company/climate-impetus
VIDEO SOURCES
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
https://www.boell.de/de/2024/11/26/wasseratlas-2025
https://www.umweltbundesamt.de/publikationen/prognostische-wasserbilanzierung-fuer-den
https://www.bwb.de/de/forschung-und-entwicklung.php
DISCLAIMER
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101037084. Funded in the EU Horizon 2020 Green Deal call.
Imagine a city where the water you drink comes mainly from the same river that flows through the streets. That’s Berlin. The water management situation is very special. It is, I think, unique. But longer periods of drought, population growth and structural changes pose risks for the city. We have to find a new solution. But we don’t act like that. And it’s not just about the quantity of water. Pollutants will always be a problem in the end then for our drinking water situation. What happens if a metropolis like Berlin faces a looming water shortage? And what needs to be done to protect this valuable drinking water system? Our planet’s water cycle is under increasing strain. In many places, the limits of sustainable groundwater use have already been exceeded. Major cities like London, Paris, and Berlin rely on groundwater. Without it, there would be no drinking water. Berlin is a particularly striking example, as the drinking water of Germany’s capital comes entirely from local groundwater. Since the amount of naturally formed groundwater is not always enough to meet demand, surface water is used to artificially recharge the groundwater reserves. About 70 percent of Berlin’s drinking water is obtained by bank filtration from Berlin’s water bodies. The abstraction through a total of 650 deep wells, lowers the water level and induces flow from the lakes and rivers back into the groundwater. The water infiltrates very slowly through many different soil layers. Bank filtration cleans the water effectively, as the sand and gravel layers underground form a biologically active filter, removing many chemical trace substances. Even traces of drugs, medicines and household chemicals can be broken down by microorganisms. In Berlin’s waterworks, drinking water is produced in natural treatment stages and finally distributed. After use, the wastewater is collected in the sewage system and pumped to treatment plants. There nutrients and other pollutants are removed before the water is reintroduced into the lakes and rivers. And then the cycle begins again. This way, around 540,000 m³ of fresh drinking water per day are delivered to 3.8 million people, to the industry, and to businesses. This is equivalent to almost 400 filled Olympic-sized swimming pools. Around a third of the water comes from here: the Beelitzhof waterworks. This is one of our three key facilities to supply Berlin with drinking water. Currently, we have the water quality that we need. But we, the last, I think, five years. So, like 2018, 2019, 2020 these were really dry years, and this kind of showed us already limits of the system that we are using here. And that brings us to the challenges facing Berlin´s water system. The effects of climate change have already been experienced. Although the average annual rainfall in Berlin has remained relatively stable at around 580 l/m², climate change is altering rainfall patterns. The region is experiencing more frequent and intense downpours as well as extended dry periods. Especially in summer, those dry periods are causing a decrease in the available surface water resources. How climate change is affecting Berlin is a really good question, because there is no clear tendency given for Berlin. I think this is something that really is different from other locations in Europe, that the climate prognosis for the different scenarios is like they have uncertainties from, it can be really wet here sometimes, to it can be really dry sometimes. And so, what is the scenario we are trying to adapt to? One factor that is likely to intensify the already visible effects of climate change is that a coal mine in Lusatia serves as an important external water source for Berlin. But why is this a problem? A considerable amount of the groundwater pumped out of this mine flows into the Spree River. So, ironically, the very industry often considered the most damaging to the climate serves as an additional vital source of water for the Spree River. But from 2038 onwards the mine will be closed and halt this artificial water supply. It is expected that water levels could drop drastically, especially in dry summer months. This will have a significant impact on the Spree Forest, the lakes and canals and Berlin’s drinking water supply. I believe that if we are doing nothing in the moment, that will change. We have to prioritize and say, okay, you are not allowed to use tap water. We have to maybe shut down some industries and maybe the forest in Berlin, I think it’s nearly 20% of city area, will not get enough water anymore. Recognising these challenges, the senate of Berlin has developed the “Masterplan Water”, a strategy to secure the city’s long-term water security, focusing on securing drinking water supply, protecting water bodies, and expanding and modernising wastewater treatment. For that the Senate has developed a total of 32 measures which involve key activities like limiting water withdrawals, reactivating old waterworks, exploring alternative water sources, promoting responsible use of water, and developing new strategies to remove trace substances and chemicals from the water. The Master Plan Water is not static, but a process of discovery, which means that it will have to be continuously updated over the years. Especially when new findings emerge, for example because we have more precise results on how the coal phase-out will affect water management conditions in Berlin. Or because we have other new findings, for example with regard to population forecasts or the effects of climate change. Sustainable water management requires diverse approaches: rainwater management, groundwater recharge, and political dialogues. Prioritising, and coordinating these measures is challenging. The European project IMPETUS provides crucial support by developing climate trend prediction strategies to improve regional responses to climate change. We need to know how is the groundwater situation? Where is the water coming from? How is it flowing? How is it changing? Or if the precipitation is increasing or decreasing. So, if the climate is changing, what does it mean in the end for the groundwater situation? The researchers use computer models to simulate how potential droughts or water body changes could affect the city’s drinking water. They analyse how different water management measures would perform in scenarios like extended droughts or the Spree River losing coal mine water. When there is a drought situation in Berlin, this goes hand in hand with less flow in the Spree River. This means that the share of treated wastewater might be higher than the actual water within these rivers. So, it’s a little bit of this, it’s not in balance anymore. To allow a higher share of treated wastewater in Berlin’s surface waters, one focus among diverse research areas is the implementation of ozonation, an additional wastewater treatment step. This method, already recommended by the European Commission, is currently being built in Berlin. But before we talk about ozonation, let’s briefly discuss how wastewater is typically treated. In a wastewater treatment plant, the first step is to remove branches and papers from the water. Followed by sand and oil. After that, microorganisms break down biological nutrients with the help of oxygen. And finally, chemicals like medical residues are removed. Now, the new treatment step ozonation is added. Ozone is a highly reactive form of oxygen and very effective at breaking down stubborn pollutants like pharmaceutical residues. The ozone itself decomposes back into regular oxygen. The researchers found ozonation destroys about 70% of a blood pressure medication by-product. Removing such pollutants allows for a significant increase in treated wastewater reuse in water bodies, potentially from 12% to 47%. The impact on other contaminants is still under investigation. In the end, we will hopefully be able to say, okay, this measure is possible, like to implement it in real and another maybe not. The results we get out of the models will be used in the end, of course, for the decision-makers, which are in our case the Senate and some parts also the BWB, because they are responsible for the wells and the drinking water situation in general. This research will show decision-makers how to keep the city’s water safe, because even though it’s stable now, action still needs to be taken. We cannot go on business as usual. And that’s the reason we try to have a picture ready, which is not looking on the yearly water demand we have, but on the water demand we have in ten years, in 20 years and then say, okay, we lack it. We don’t know if it happens in ten years, if it happens in 15 years, but it will happen. How will you react? How do we want to react? It’s clear that without preparation, Berlin could face serious consequences for its people, environment, and economy. However, Germany’s capital also demonstrates that megacities can proactively respond to climate change, recognising and addressing these changes early on.