The upper Rhine aquifer: the greatest EU potable water reservoir
The Upper Rhine aquifer is one of the most extensive European aquifers, holding between 65 and 80 billion cubic meters of water. It is vital to the Alsatian economy and provides 75% of the drinking water requirements, 50% of the industrial water requirements, and s0% of the irrigation water requirements. Subject to enormous anthropogenic strain, the aquifer greatly suffers from pollution from various sources since this shallow groundwater is particularly vulnerable. The Alsace valley is also a rich ecological environment, with large forests and numerous wet zones, as the famous Ried region between the Ill and Rhine rivers in the central part of the plain, leading to an important biodiversity that is protected in several natural areas.
The current state of the aquifer and the associated ecosystems is fragile, since the water quality and quantity may significantly change in a near future due to climate change and anthropogenic pressure. The snowpack will be deeply reduced shortly, impacting both the upper Rhine basin and its tributaries in the whole Rhine Valley. The concentrations of various contaminants/metabolites already exceed limits for drinking water potability. Anthropogeneic activities thus threaten both short term and long term water availability and quality.
Key issues and how the observatory will help to tackle them
The Upper Rhine aquifer has already been studied in several national and international projects. Its functioning is nonetheless still not sufficiently known and key information on the system and associated human activities are lacking. The Aquifer Living Lab will be a demonstrator of collaborative work between academic research, public stakeholders and private companies that aim at producing improved knowledge on how the Upper Rhine aquifer will evolve due to global changes and co-construct alternative agriculture and water use practices that make the system more resilient.
More specifically, the Aquifer Living Labs will focus on (i) quantifying the evolution of water resource in the Rhine aquifer under future climate; (ii) studying the impact of agricultural practices on water availability and quality; (iii) improving survey and collection of information on lacking information (pumping rate and pesticides applications); and (iv) co-construct alternative and more resilient scenarios for agriculture and water use. This will implies new methodological developments on water resources models to better integrate human activities, on reactive transport models to enable water quality simulations at the catchment scale and on the quantification of modelling uncertainties. Advances in monitoring and survey of water use and pesticides application are also planned. The developed tools and acquired dataset will be used to define and assess future scenarios, to feed long term decision-making, and implement more sustainable water management policies in the Upper Rhine territory.