WP1 establishes the grounds for purposeful and context-sensitive stakeholder engagement in every pilot site through the establishment of Communities of Practice (CoPs). It maps quintuple-helix stakeholders across social and economic sectors, identifies their needs, responsibilities and potential conflicts, and integrates their feedback into the design, implementation and validation of the INVESTWATER decision-support toolbox. WP1 also delivers capacity building and training on NBS, coordinates dissemination and communication, maintains synergies with related projects and initiatives, and carries out policy mapping and coherence assessment for NBS implementation at local and EU level.

WP2 develops a participatory, criteria-based procedure to identify and characterize NBS with the potential to enhance groundwater quality and recharge (NBS-to-MAR). It assesses and maps the spatial distribution, typologies and functional roles of existing and potential NBS using GIS, remote sensing and field surveys; explores the role of NBS in supporting groundwater-dependent ecosystem services (GDES); builds an open-access, structured NBS catalogue; and produces stakeholder-validated NBS Opportunity Maps at watershed scale for each pilot site.

WP3 evaluates and validates the performance of the identified NBS using a framework aligned with the IUCN Global Standard, analyses the impact of NBS on social equity and justice, and evaluates their cost-effectiveness. Its results feed a dynamic Decision Support System — coupling WEAP, MODFLOW and SWAT models — that guides the prioritization and enhancement of NBS across the four pilot sites, with interventions selected and validated together with local authorities and communities.

WP4 establishes the metrics for evaluating the performance of selected NBS under fit-for-purpose operational scenarios coupling NBS to MAR systems, with dual environmental benefits for ecosystems and groundwater. It co-develops an intervention Action Plan with key stakeholders — covering monitoring, technical, governance and social measures — and converts it into real-scale interventions at the pilot sites, including infrastructure enhancement, fit-for-purpose monitoring systems (with real-time instrumentation, remote sensing and geophysical surveys) and supporting governance strategies.

WP5 designs the Adaptive Scalability Framework (ASF) to guide NBS-to-MAR scaling out (replication across river basins), up (integration into institutional frameworks, policies and financing programmes) and deep (transformational shifts in stakeholder values, knowledge and capacities). The ASF is tested in frontrunner pilots and transferred to follower sites through tailored training and peer-to-peer learning. The WP culminates in context-aware Scalability Roadmaps that connect NBS initiatives with financing stakeholders and mechanisms, transforming conceptual frameworks into actionable, investment-ready projects.

WP6 covers the contractual, operational and financial management of the project, along with the coordination of technical, quality and innovation issues. It includes quality assurance and risk management, as well as privacy, ethical, legal and regulatory data compliance, supported by a living Data Management Plan.