Environmental Perspectives 12/2018
Water supply security by 2030 – utopia or a realistic goal?
"Water, water, everywhere, nor any drop to drink." This quote is from "The Rime of the Ancient Sailor" by Samuel Taylor Coleridge (1772–1834). The core of this insight is that although there were no global water balances in the 18th century: Water is in abundant supply on earth, but only a small fraction of that can be used by humans. More precisely: Of the 1.4 billion cubic kilometres of water globally available, 97.5 percent is salt and another 2 percent is bound in ice and snow. Less than 1 percent remains as freshwater on the continents, of which the global population is currently using roughly 4,000 cubic kilometres per year. This corresponds to one third of the renewable freshwater resources, with an increasing trend.
Global wastewater flows will double by 2050.
Moreover water security also requires sufficient quality. Water may be unsuitable for use due to natural conditions or may be impacted by human contamination with substances. This is not inherently critical, as water has the amazing ability to continuously renew itself through the water cycle in the atmosphere, soil, groundwater and in the surface waters – as long as this natural "self-purification" is not overloaded. Starting from the 19th century, population growth and industrialisation brought Central Europe to this point. It was necessary to build-up infrastructures and purification technologies at large scales to help solve the problems of safe drinking water provision and sufficient wastewater treatment.
The lesson learnt from this experience was that the drinking water supply, sanitation, wastewater treatment and the water bodies must be considered together. But this is still ignored even in major water programs.. For example, one of the "Millennium Development Goals" of the United Nations in 2000 was to halve the number of people without secure access to hygienically safe drinking water and basic sanitation by 2015. This is a necessary and reasonable step for humanitarian reasons but is not without consequences for water quality, because these UN goals did not account for adequate treatment of the produced wastewater. A study coordinated by the UFZ under contract to the UN Environment Programme thus revealed that wastewater in Africa, Asia and Latin America is currently being discharged largely untreated into surface waters, and that whole river networks are already hygienically critically polluted over up to a third of their length.
And this problem will quickly be aggravated, as wastewater flows will double by 2050 due to global growth in population. The good news from this study was that two-thirds of the water bodies on these continents still have good to very good water quality and are also still largely intact from an ecological perspective. Given current experience, available knowledge and the many available technologies, all of the prerequisites are met to at least maintain this level. What is lacking are regionally adapted and integrated solution concepts that complementary account for the social, economic and legal conditions and that are actually implemented.
The situation in Germany and Europe is quite different. In this case, nearly the entire population is connected to functioning drinking water and wastewater infrastructures. However, this is contrasted by the fact that more than 90 percent of surface waters in Germany and 60 percent across Europe are in a "moderate" to "poor ecological condition". And nothing has changed here even though the EU Water Framework Directive has required that water bodies be brought to "good status" by 2027. The programmes of measures planned at great expense are evidently ineffective and have to be re-evaluated fundamentally.
If water supply security is truly to be comprehensively and sustainably achieved, the quantitative use of water, the substance loads and the water ecosystems as a whole must be managed in such a way that the regenerative capability of the water cycle and its ecological function are retained over the long term. This requires a new systems approach in water research and water management.
90% of surface waters in Germany and 60% in all of Europe are in a "moderate" to "poor ecological condition".
How can we build on this experience and what will be important in the future? One thing is clear: Pressures on the availability of water and the associated ecosystem capacities have increased significantly, and will continue to increase, as a result of global change and increasing global population. The challenges of today and the future must therefore be recognized as complex problems of water availability resulting from a combination of limitations in quantity and quality, with the potential for significant conflicts in the event of different utilisation interests. Unresolved questions range from water supply and disposal security, food security, protection against extreme events such as droughts and floods, to health care and the energy supply to the preserving biodiversity.
Water supply security, which we all need and which has received a political mandate from the international community through the UN's 2030 Agenda, can only be achieved through system solutions. Sanitation and clean water in sufficient quantity are basic prerequisites for the achievement of practically all of the 16 other Sustainable Development Goals. The task of future-oriented water research is to take a comprehensive approach to analysing and understanding the complex nature of water availability and security. It must further develop and test solution options and guide them all the way to implementation in interdisciplinary cooperation with policies, economy and civil society. No one should wait until 2030.
To cover story Environmental Perspectives 12/2018:
Water security by 2030 – utopia or a realistic goal? (in German)