Managed Aquifer Recharge (MAR) using irrigation channels: experiences from the test sites of the SeTe-ALCOTRA project

Climate change is threatening both the quantity and quality of groundwater resources, as scarcer rainfalls and prolonged droughts reduce natural recharge and increase reliance on groundwater abstraction. In this context, Managed Aquifer Recharge (MAR) is a climate change adaptation measure that, through the intentional recharge of aquifers with excess surface water, provides water underground storage for later use (e.g., irrigation) and may improve groundwater quality (e.g. addressing saltwater intrusion or nitrate pollution).

The SeTe (Sécheresse et Territoires) project, funded by the EU Interreg ALCOTRA programme, involves the feasibility study and demonstration of MAR at three sites – Beinette, Tetti Pesio and Tarantasca – in the Cuneo plain, a large shallow alluvial aquifer in northwestern Italy. In this intensively farmed area, with a large seasonal mismatch between water supply and demand, groundwater use for irrigation is widespread and recent droughts and human pressures have caused severe aquifer depletion. This issue is particularly relevant in the SeTe test sites, where irrigation water is supplied through wells and semi-natural lowland springs (fontanili), drainage trenches excavated since the Middle Ages to reclaim the marshy lands conveying the drained groundwater to irrigation canals. As groundwater levels decline, many wells dry up, or show reduced yields, and fontanili discharge decreases or ceases. Experimental recharge trenches were built within the project to supply the aquifer by infiltrating water from canals when they are not used for irrigation. This water, which would otherwise flow into water courses, is infiltrated upstream the fontanili to raise local groundwater levels and enhance their drainage capacity.

After the geological, hydrological and hydrogeological characterization of the area carried out in the first year of the project, two infiltration trenches were completed in Beinette and Tetti Pesio by spring 2025. Then, the trenches were tested until the start of the irrigation season, while a full infiltration season was planned for winter 2025-2026.
Water levels in monitoring wells, fontanili and recharge trenches, as well as recharge flow rates, are continuously monitored through a monitoring network, also using LoRA-based systems to enable real-time data acquisition. Water chemistry monitoring is carried out to ensure that the infiltrated water is of higher quality than the groundwater, often affected by nitrate contamination.
Meteorological and hydrological data, including rainfall, snowfall and rivers flows, are integrated from the regional monitoring database to understand the overall system behaviour, with a focus on quantifying recharge and its beneficial effects on groundwater levels and fontanili discharge. 

Despite operational challenges, such as clogging, the SeTe ALCOTRA project is demonstrating that with its cost efficiency, simple design and minimal environmental impact, MAR is a suitable strategy for aquifer recharge, supporting ecosystem services and economic activities.
Finally, public engagement, both with authorities and local communities – is a key aspect, as it can facilitate the adoption and dissemination of this type of infrastructure.