In the 21st century, more than 25% of Latin America’s urban population already lives under moderate to severe water stress, and coastal cities such as Recife face a double risk: the overexploitation of their aquifers and saltwater intrusion accelerated by climate change and sea level rise. The Beberibe Aquifer, historically a key source of supply for the metropolitan region, has seen its effective capacity reduced after decades of unregulated extraction and insufficient recharge, with direct impacts on the availability and quality of water for human consumption, industrial use, and ecosystem maintenance.
This project is designed as a strategic response to that reality: an integrated plan for aquifer restoration and sustainable management that combines green infrastructure, managed recharge, digital monitoring, and multi-stakeholder governance. The intervention aims not only to increase annual recharge volumes by up to 5 million m³, equivalent to the domestic consumption of more than 80,000 people, but also to improve the physicochemical quality of groundwater by reducing the intrusion of contaminants and salts.
Its rationale is clear: without decisive action, Recife’s projected water deficit could surpass 30% within the next decade, compromising the water security of communities and key productive sectors. By aligning with the Water Positive strategy, the project ensures that each additional cubic meter of water recharged and protected complies with the principles of additionality, traceability, and intentionality, validated under VWBA and WQBA methodologies for both physical and digital benefit verification.
The initiative is driven by a consortium that includes the local water utility, hydrogeology research institutions, technology providers for sensing and modeling, and an independent third-party verifier. This alliance ensures not only the technical robustness of the solutions but also their alignment with global sustainability agendas, particularly SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Cities and Communities), SDG 13 (Climate Action), and SDG 15 (Life on Land).
The technical opportunity arises from the urgent need to reverse a degradation process that, if left unaddressed, will cause irreversible losses in both the quantity and quality of groundwater. Currently, the Beberibe Aquifer suffers from continuous piezometric declines, saltwater intrusion in coastal areas, and diffuse contamination from urban and agro-industrial infiltration. Pressure on the resource is exacerbated by the lack of infrastructure for artificial recharge, limited sanitation coverage in the region, and the absence of an integrated monitoring system.
The proposed solution integrates three pillars:
In the short term, the project aims to halt the decline of groundwater levels and recover up to 1.5 million m³/year in pilot zones. In the medium term, the objective is to stabilize the saltwater wedge and reduce chloride concentrations in supply wells by 15%. In the long term, restoring the aquifer’s functionality will reestablish it as a form of natural infrastructure, critical for regional water resilience.
This model is highly replicable: any coastal city with overexploited aquifers can adopt it, adapting to local geology and recharge conditions. For companies and institutions with ESG goals and water neutrality commitments, it represents an opportunity to invest in natural infrastructure with high environmental, reputational, and social returns, positioning themselves as decisive actors in shaping urban water security.
Facing this complex issue, the proposed solution is structured around a multi-component technical-operational strategy designed to address both structural causes and active degradation vectors. Actions are distributed across three main fronts:
Advanced diagnosis and technical characterization: A detailed mapping of the region is carried out using multispectral satellite remote sensing (Sentinel-2), infrared thermography, and drone flights equipped with LIDAR and multispectral sensors. This information is processed using GIS tools to identify hotspots of water risk, thermal depressions, changes in surface moisture, and topographic anomalies that may suggest the presence of active, abandoned, or decommissioned wells. Field validation is conducted through georeferenced inspections, sample collection, and measurement of key variables such as groundwater level, electrical conductivity, water temperature, and chloride concentration.
Hydraulic intervention and well sealing: Based on a hydrogeological risk index, wells whose morphology and location represent a higher probability of connection between contaminated layers are prioritized. The intervention is carried out using progressive sealing techniques with bentonite slurries, expansive cement mixtures, or polymeric resins, depending on depth, lithology, and structural collapse degree of the well. Each action is documented with technical sheets, satellite images, and geo-referenced work reports. This procedure cuts off unwanted vertical flows and eliminates contamination entry/exit vectors.
Implementation of managed recharge zones: In areas identified with hydrological potential, urban parks, green corridors, or non-urbanized peri-urban land, biofilters are built as semi-deep infiltration systems. These biofilters consist of a stratified combination of silica sand, washed gravels, activated carbon, geotextiles, and native vegetation adapted to wet soils (such as Cyperus, Heliconia, or Typha). Their function is to capture rain runoff, filter physical and chemical contaminants, and allow slow, regulated infiltration towards the water table. These structures are hydraulically modeled and monitored in real-time using flow sensors and automatic piezometers, which allows evaluating their performance and long-term impact.
Each of these lines of action is accompanied by a participatory governance strategy involving local authorities, water companies, research centers, and community organizations, ensuring sustainability, territorial appropriation, and synergy among stakeholders.
The project implementation is organized into five consecutive phases, with differentiated and overlapping activities that ensure comprehensive technical control of each component:
Phase 1 – Remote Diagnosis (Months 0 to 2): Initial cartography is developed using multispectral Sentinel-2 images, digital elevation models, and thermal remote sensing. Risk maps are generated and linear structures, thermal anomalies, and changes in NDVI index are identified. Municipal geographic information system databases and CPRM hydrogeological cartography are incorporated.
Phase 2 – Field Validation (Months 2 to 4): Wells are physically inspected, their structural status is determined, piezometric records are taken, and water samples are extracted for certified laboratory analysis (chlorides, EC, nitrates, turbidity, heavy metals). Permanent control points are installed to establish the baseline quality and water table level.
Phase 3 – Intervention Design (Months 3 to 5): Sealing plans for wells and hydraulic design of recharge zones are prepared. Constructive parameters, materials, expected flows, vegetation coverage, and construction schedules are defined. Key performance indicators (KPIs) and regulatory requirements for environmental permits are established.
Phase 4 – Construction Execution (Months 6 to 10): Progressive technical sealing of wells is performed with volume and resistance control, according to ABNT standards. Biofilters are constructed at selected sites with sensor instrumentation for flow, observation wells, and automatic weather stations. Each intervention is documented with full traceability (well ID, material volume, tightness test results).
Phase 5 – Continuous Monitoring and Reporting (Months 10 to 24): A real-time monitoring network connected to a digital platform records piezometric level, EC, temperature, accumulated infiltration, and precipitation. Quarterly external audits are conducted and verified water benefits are reported on Aqua Positive. The VWBA approach is applied using the formula:
Meanwhile, the WQBA approach quantifies the percentage improvement in water quality by reduction of measured pollutants compared to initial concentrations, validated by an external lab and maintained for three consecutive quarterly cycles.
In the Metropolitan Region of Recife, one of the most densely populated urban centers in northeastern Brazil, the coastal Beberibe aquifer faces severe deterioration due to saltwater intrusion, historical overexploitation of wells, and progressive soil impermeabilization. This aquifer, which supplies more than three million people, has a stratified structure and high hydraulic connectivity, making it particularly vulnerable to imbalances induced by ocean pressure and falling piezometric levels.
The project “Groundwater Guardians – Recife” proposes an integrated intervention aimed at restoring aquifer functionality, recovering its recharge capacity, and improving stored water quality. The strategy is based on a combination of remote monitoring technologies, high-resolution hydrogeochemical diagnosis, technical sealing of critical wells, and the installation of managed recharge zones through nature-based solutions.
The methodological approach combines two complementary frameworks: Volumetric Water Benefit Accounting (VWBA) to quantify induced additional recharge, and Water Quality Benefit Accounting (WQBA) to measure actual improvements in parameters such as chlorides, electrical conductivity, and nitrates. Both approaches include external verification and digital traceability via platforms like Aqua Positive.
Project actions are deployed in five phases: remote diagnosis using satellite imagery and drones; field validation with piezometric measurements and chemical analyses; technical design of hydraulic works and green infrastructure; execution of progressive well sealing and biofilter construction; and finally, continuous monitoring with IoT sensors connected to a digital analysis platform. Throughout the process, compliance with key performance indicators (KPIs) is ensured, and local governance mechanisms are established with participation from environmental authorities, universities, water operators, and communities.
The project is located within the hydrogeological unit of the Beberibe aquifer, crossing municipalities such as Recife, Olinda, Paulista, Jaboatão dos Guararapes, and Cabo de Santo Agostinho. This area has been identified by the Brazilian Geological Service (CPRM) as highly vulnerable to marine salinization due to its interaction with estuarine bodies, urban density, and low natural recharge capacity.
From a sustainability perspective, the intervention directly contributes to the Sustainable Development Goals: it improves public health (SDG 3), ensures access to clean water (SDG 6), drives innovation in resilient infrastructure (SDG 9), strengthens climate adaptation in urban environments (SDG 11 and 13), restores degraded ecological functions (SDG 15), and fosters inter-institutional partnerships (SDG 17). Additionally, it enables the generation of Positive Water Credits (PWCs) as an instrument for environmental valuation and climate financing.
This advanced hydrological restoration model has replication potential in multiple coastal basins in South America under water stress, consolidating a technical, participatory, and results-oriented governance approach.
