Background In several parts of the EU, water extraction for agricultural irrigation, along with the continuous application of fertilisers and pesticides, often in greater quantities than necessary, are leading to surface and groundwater pollution. Through water seepage and run-off, these processes lead to the contamination of groundwater and surface water respectively. Also, the connection between the alluvial aquifers and surface water allows, in certain stretches of rivers, pollutants to reach the surface water through groundwater transport. The contamination of groundwater and surface water bodies causes a deterioration in river ecosystems and in riparian and aquatic communities, and lowers the quality of water used for other consumption purposes, mainly due to the presence of toxic compounds and environmental pollutants. Objectives The REAGRITECH project aims to demonstrate the feasibility of regenerating and reusing irrigation waters (runoff and infiltration) by using natural treatment systems. Runoff and infiltration waters originally coming from irrigation will be collected and reintroduced to the system, thus saving water resources. Lowering the amount of pollutants in irrigation waters will also decrease the amount of nutrients and pesticides in the soil and in surface and ground waters. The treatment of drainage water for agriculture irrigation will have no impact on the local hydrological balance; excess water will be added to groundwater in order to restore aquifer levels. The efficiency of natural water treatment technologies for nutrient and pollutants (such as pesticides) reduction from drainage water will be tested throughout the project. To this end, two constructed subsurface wetlands and buffer strips will be used to improve the quality of the collected water and to aid the reuse of such water for irrigation purposes. The buffer strip systems will ensure the effectiveness of the sanitation process of the treated waters, which will then, through infiltration, go on to feed the aquifer and later the river. These natural systems are not harmful to the environment, as they don’t use energy or chemical products and, therefore, represent a good option for sustainable and integrated water basin management. Expected results: A reduction of 50% in the volume of water used for irrigation systems; An increased in the percentage of water reused in irrigation; Enhanced removal of nutrients and pesticides with natural treatment systems; Reduced consumption and extraction of water for agriculture, leading to a reduction in the exploitation of aquifers and river systems during the modernisation of irrigation systems; Decreased human pressure in vulnerable areas: the decrease in the pollution load in aquifers and rivers will decrease the pressures of agriculture on the hydrological system of the basin; Improved riparian habitats: the combination treatment by the constructed wetland with the buffer strip will improve riparian habitats and thus associated ecosystems; Reduced carbon footprint: the buffer strips, as well as being part of the treatment system for water from agricultural use, will allow for the reforestation of degraded areas using native species that can capture a significant amount of CO2 from the atmosphere. Reduced carbon emissions: reforestation, and the use of renewable energy (solar cells) in processes that require energy, are positive steps towards combating climate change.