Example of the implementation of controlled recharge solutions: filling infiltration basins with water from the Seine at a site in the Croissy-sur-Seine catchment area
© Suez
The need
Water resources in the Indre-et-Loire département are subject to conflicts of use when demand exceeds the available water. Among the possible solutions for reducing this pressure on water resources, controlled aquifer recharge techniques have a number of advantages, including flexibility in water resource management, limiting the effects of periods of drought on water resources, reducing surface water abstraction during periods of water stress and restoring hydrosystems.
To implement this type of project, an abundant source of good quality water is needed. There are generally three types of water recharge sources: surface water, treated waste water and desalinated water. In consultation with the project partners for the Indre-et-Loire département, only recharge by surface water from infiltration basins was envisaged, in specific sectors of the département where natural measures for retaining groundwater in winter (by planting hedges, re-establishing wetlands, agro-forestry, etc.) would help to recharge the aquifers in the short or medium term. This would increase their availability in summer, either for direct abstraction from the aquifer or by recharging watercourses.
The results
A combined analysis of physical criteria, linked to soil, geological and hydrogeological characteristics, constraints and use, and the proximity of surface water, led to the selection of ten favourable areas in the department, and more specifically in the following 4 types of aquifers: alluvial, Tertiary, chalk and Cenomanian.
Using the results
For the rest of the study, the ten favourable areas will be prioritised by integrating other criteria (local constraints, master plan for water development and management - SDAGE, drained surface areas, water quality, etc.) in order to size one or two controlled aquifer recharge sites using specific modelling tools.
The partners
- Direction départementale des territoires d’Indre-et-Loire
