Projects - OneWater Calls for Proposals

Project owner: Danièle Valdes and Corinne Le Gal La Salle 

Coordinating institution: Sorbonne University 

Against a backdrop of global change and increasing pressure on freshwater resources, enhancing groundwater recharge is a major challenge. Natural Water Retention Measures (NWRMs), combined with the use of non-conventional water sources such as urban and agricultural runoff or treated wastewater, offer promising opportunities. However, their implementation raises questions about their effectiveness, their effects on groundwater quality, their costs and their social acceptability.

Selected under the OneWater – Eau Bien Commun programme’s 2024 Wall-Free Lab call for proposals, RECHARGE aims to improve understanding of the opportunities and limitations of these systems and to develop sustainable water resource management strategies jointly with stakeholders.

The project addresses four main questions: to what extent can these systems increase groundwater recharge? How effectively can receiving environments remove chemical and microbiological contaminants? Which indicators can be used to monitor their functioning? What are the societal barriers to and drivers of their implementation?

To address these questions, RECHARGE combines hydrogeology, geochemistry, microbiology and modelling with the humanities and social sciences, particularly economics, environmental psychology and social design. Its research brings together hydrodynamic and geochemical simulations, investigations into the fate of contaminants and pathogens, cost–benefit analyses, and the exploration of perceptions associated with recharge systems and the different types of water infiltrated.

These approaches inform one another: modelling results and economic assessments support the co-construction of solutions, while scenarios developed with stakeholders are subsequently evaluated using the models. Working closely with stakeholders, RECHARGE aims to produce knowledge and decision-support tools to guide groundwater recharge choices tailored to local needs and challenges.

Project owner: Florentina Moatar 

Coordinating institution: INRAE

Rising river temperatures are an established consequence of climate change and are expected to be exacerbated by human activities. Their direct consequences are already apparent, adversely affecting ecological functioning, human health and economic activities such as electricity generation.

The overarching question addressed by ThermieFrance is not whether water temperatures will rise, but by how much and where, how they will vary, and what ecological and socio-environmental consequences this variability will have.

To address this multidimensional question across multiple scales, ThermieFrance adopts an interdisciplinary approach through doctoral and postdoctoral research, with researchers working closely together and with water stakeholders.

WP1 will operate at regional (Seine, Loire and Rhône basins) and national scales. It aims to predict changes in hydrological and thermal regimes and their consequences for biodiversity.

It will use signatures derived from hydrometric and temperature observations, alongside three types of thermal and hydrological models validated against observed data. These signatures will help characterise monitoring sites influenced by groundwater, which could potentially serve as refuges (WP2).

Drawing on fish time series available across the French river network and historical, present-day and future outputs from thermal and hydrological models, the project will deliver major methodological advances in simulating the magnitude and speed of these changes’ impacts on freshwater fish biodiversity, including species extinction rates.

WP2 will operate at the local scale to investigate thermal anomalies and their potential role as ecological habitats, a crucial issue in the context of climate change.

ThermieFrance will first investigate the hydrogeological controls on thermal anomalies and predict their evolution under different climate and water abstraction scenarios. It will then examine how these regimes and changes influence ecological habitats.

Although the importance of cool thermal refuges in summer was recognised early on, recent studies have highlighted the significance of warm refuges in winter, which are also sensitive to global warming, particularly for individual growth. Thermal refuges could represent a bottleneck in population dynamics and a key consideration in developing adaptation measures, and therefore warrant detailed investigation.

WP3 aims to test different scenarios for reducing river temperature fluctuations and increasing thermal resilience across all scales. It will involve stakeholders in knowledge production, the exploration of perceptions of the issues, and the assessment of potential solutions. Thermal refuges will be examined as environmental features that different social groups perceive and interpret in different ways, and that may motivate action.

WP3 will quantify the benefits of different adaptation measures using spatial analyses, models and interactions with socio-economic stakeholders and associations, particularly fishing federations, through social surveys and a participatory approach. The aim is to translate the project’s findings into practical tools and support their communication and dissemination, enabling their implementation and use to inform action.

Project owner: Tristan Lefebure

Coordinating institution: Claude Bernard Lyon 1 University

In a global change context and the need for sustainable use of our water resources, the living organisms present in socio-hydrosystems are both a rich biodiversity to be preserved but also the reflection of the state of functioning and integrity of these environments. Environmental nucleic acids (eNA) are molecules of multiple biological origins (from viruses to eukaryotes) taken directly from the environment. Recent developments in molecular biology have made it possible to employ eNA to characterize the impact of the quantitative and qualitative conditions of water resources on biodiversity, for instance through the variety and abundance of organisms or the expression of molecular functions. In this way, eNA can serve as sentinels of the ecosystem health status in the face of multiple biotic and abiotic stresses (global warming, pollution, anthropic activities, arrival of invasive species and pathogens).

Despite considerable progress in the use of eNA, operational transfer remains limited due to a lack of knowledge on the ecology of eNA along the hydrological continuum and the delay in the implementation of certain water bodies (e.g. groundwaters). The ALIQUOT project aims to fill these gaps by acquiring fundamental knowledge on the spatio-temporal dynamics of eNA in continental aquatic ecosystems in order to use this knowledge to identify solutions promoting the adaptation and resilience of socio-ecosystems.

ALIQUOT aims to develop new methodologies to describe biodiversity qualitatively and quantitatively, monitor the emergence of non-native or pathogenic species and characterize the health and functioning of these ecosystems in a reliable and reproducible manner. ALIQUOT thus intends to contribute to the objectives of OneWater by removing the numerous scientific and technological barriers that currently hinder the operational deployment of eNA to meet the challenges of sustainable water management in all continental hydrosystems. Through the production of knowledge on eNA’s ecology, innovative protocols and reference data, the project will support social and economic actors in the transformation of their practices.

The solutions proposed by ALIQUOT will enable non-invasive monitoring with low environmental impact and increased surveillance to promote early responses in the event of risks to the water resource. These solutions will lead to a better monitoring of the health of populations, to the constitution of efficient pathogen monitoring networks, and will improve access to safe drinking water. The project will provide a more holistic approach to ecological diagnosis and will facilitate the use of this biological and ecosystem information for the management of socio-hydrosystems. ALIQUOT relies on a consortium of research laboratories that are pioneers in these fields, as well as methodological approaches in the laboratory and in the field that make use of existing sites, national infrastructures, and monitoring networks (AnaEE and ZA). 

Project owner: Christelle Marlin

Coordinating institution: Paris Saclay University

With the increasing recurrence of extreme weather events and increased anthropogenic pressure on water resources, confined groundwater aquifers and more generally aquifers under impermeable sedimentary cover (CAq) are still largely free from anthropogenic impacts. These aquifers can contain significant quantities of water, generally of good quality with regards to drinking standards. They are not very sensitive to summer water shortages because of their inertia.

During episodes of restrictions on the use of surface water or groundwater, CAq could be more solicited to ensuring our water safety but intensive and poorly controlled exploitation of their resources could endanger the sustainability of these resources. It is also our responsibility to preserve them for future generations.

The DEESAC proposal (Sustainability and Exploitability of Groundwater in Confined Aquifers or Unconfined Aquifers below non-confining beds – called CAq) aims to define, on the basis of a scientifically sound and accepted arguments, a methodological guide for the sustainable exploitation of CAq in France, based on a set of indicators and proxies. DEESAC integrates as sine qua non conditions that 1) the increasing demand of these groundwaters must respect the hydrogeological balance between recharge flow and exploitation rate, as well as the water quality (any imbalance of water budget induced by an overexploitation of CAq must therefore be anticipated) and 2) that the indicators and thresholds that will be proposed will have to be codesigned with stakeholders. The aim is to respond to the growing challenges of the sustainability of clean water resource needs.

DEESAC is part of the priority thematic area 3.1 of challenge 3. The project will be based on 4 pilot aquifers under three different hydrogeological and climatic contexts (Beauce limestone near Orleans in the Paris Basin, Eocene-Oligocene and Miocene in the south of Bordeaux in the Aquitaine Basin, and sandstoned limestone of the Burdigalian near Nîmes in South-East Basin). These aquifers have an active recharge, even low, direct or indirect, guaranteeing the renewal of groundwater

Beyond the acquisition of crucial information for aquifer sustainable management (e.g. structure, lithology recharge, groundwater residence time, leakage, geochemical background, etc.), the objective of DEESAC is to test tools, to co-design and to develop the recommendations necessary for the sustainable management of CAq as well as to propose alert modes, in connection with stakeholders (water agency, water union).

The indicators that will define management "thresholds" will be intended for water stakeholders (managers, legislators and decision makers). DEESAC will revolve around 4 main tasks with interactions between them: 1) Acquisition and integrated valorization of knowledge of hydrosystems through a multidisciplinary approach, 2) Predictive assessment methods of the vulnerability of CAq, 3) Co-design of new solutions for the sustainable management of CAq and 4) Citizen awareness of groundwater issues through communication actions.

Project owner: Véronique Léonardi

Coordinating institution: Montpellier University

This project aims to identify the impact of global changes over time on karst water resources (groundwater and surface water) in order to propose adaptation solutions to the main users, with a multi-disciplinary approach that is either horizontal (spatial variability), vertical (processes at the interfaces of the Critical Zone), or transversal (interaction between conceptual model / physical model and concerted management of the water resource).

To advance water management strategies adapted to these karst hydrosystems in the context of global change, it is necessary to have a better consideration of the specificities of these hydrosystems, from their infiltration zone to their outlets. This is possible by having a better understanding of -(i) the recharge and its sensitivity to different pressures (WP1), -(ii) the water storage in the reservoir and its transfer to the outlet according to the karstification processes (WP2). Another challenge is to trace the origin and transfer of chemical and microbiological contaminants within the aquifer and to develop indicators of the quality of the resource for the development of Early Warning Systems (WP3). For this, a quantitative approach requires the integration of multi-disciplinary observations (geo-historical, climatic, hydrological, geological, geophysical etc.) in hydrogeological models of these reservoirs, the sensitivity of the different parameters (input/output, internal) and data (measured/observed) will be tested (WP4).

This multi-disciplinary and integrated approach from upstream to downstream will allow identifying the parameters or the observations acquired continuously, necessary to set up warning systems for hydrological (in particular for extremes) and sanitary risks. In parallel with the development of scientific tools for a better understanding of the impact of global changes on the functioning of karst hydrosystems, concertation actions between scientists, operational actors, managers and users will be set up (WP5). This transversal dialogue between different actors will promote information sharing throughout the project, allowing scientists to better parameterize their models, operational actors to use them to help them develop their policies for the protection and management of the resource and users to better perceive the relationships between the elements and understand the policies implemented (all WPs).

Conceptual models realized by considering the upstream-downstream hydrological functioning, the current governance and the evolution factors to be considered will allow identifying the leverage points to improve the management (all WPs). This project will be carried out on karstic hydrosystems in (i) a highly anthropized context, with the Lez aquifer, which supplies the city of Montpellier; (ii) the Loue catchment (Jura), where land use and occupation have changed significantly since the 17th century, between forestry, agriculture and livestock; and (iii) the Fontaine de Vaucluse site (Vaucluse), which has the largest flow in Europe and whose resurgence is currently an important tourist attraction and supplies a large irrigation network. These sites are subject to various climates: Mediterranean for the Lez and Fontaine de Vaucluse, continental for the Loue.