This project aims to restore the hydrogeological functionality of the coastal and fluvio-alluvial aquifer of the Chira River Valley and the Piura area, one of the most vulnerable regions to groundwater salinization in northwestern Peru. The increasing agricultural expansion, combined with traditional low-efficiency irrigation infrastructure, has led to the intensive use of deep and semi-deep wells, many of which operate without technical oversight, valid permits, or have been abandoned. This situation has created undesirable vertical connections between aquifers of differing water quality, facilitating the intrusion of saline water from both coastal zones and deeper layers affected by residual salinity.
The intervention zone is located in the alluvial valleys of the Chira River and its tributaries, covering districts such as Sullana, Marcavelica, Las Lomas, La Huaca, and the city of Piura. These areas have shown a progressive deterioration in well water quality used for irrigation, informal human consumption, and small agro-industrial applications. The aquifer is unconfined to semi-confined, with strong interaction with open irrigation channels and water bodies contaminated by agricultural runoff and urban discharges.
The project proposes a multi-component technical solution combining satellite detection and field inspection, progressive hydraulic sealing of inactive or critical wells, and the development of managed recharge zones in degraded agricultural lands. This strategy integrates the VWBA (Volumetric Water Benefit Accounting) and WQBA (Water Quality Benefit Accounting) methodologies, enabling the quantification of improvements in both groundwater availability and quality through verifiable and measurable interventions. Implementation is supported by local governance involving irrigation user associations, local governments, universities such as UNP, and technical agencies like ANA and SENAMHI.
The deterioration of aquifers in the Chira River Valley and Piura region is caused by multiple interrelated factors. First, the indiscriminate use of deep agricultural wells, particularly in areas dominated by rice, banana, sugarcane, and lemon monocultures, has caused a sustained drop in the water table, altering the natural hydraulic gradient that previously acted as a barrier to saline intrusion. Many of these wells have been abandoned without technical sealing, turning them into open conduits for saline water from coastal or mineralized deep layers.
Second, intensive agricultural development has involved massive use of nitrogen fertilizers and pesticides, which leach into the subsoil and alter the aquifers’ chemical composition. This phenomenon—combined with flood irrigation and lack of soil conservation practices—promotes secondary salinization, as evidenced by hydrochemical analyses showing high levels of chloride, sodium, sulfate, and electrical conductivity.
Finally, unplanned urban expansion around Piura and Sullana has caused soil impermeabilization and domestic discharges in areas not connected to the sanitation network. This reduces effective natural recharge and increases contaminant pressure on the aquifer system.
The technical solution is structured around three complementary pillars:
Remote detection and hydrochemical characterization: Satellite imagery (Sentinel-2 and Landsat 8) and elevation models are used to identify abandoned wells, subsidence zones, salinized areas, and runoff traces. This information is validated through field campaigns using multispectral drones, differential GPS, and groundwater sampling for analysis of EC, chloride, nitrate, sodium adsorption ratio (SAR), and coliforms.
Physical intervention and technical well sealing: Priority is given to wells with the highest hydrochemical risk or vertical connectivity. Sealing is done using controlled cementation techniques, with field-based depth and lithology profiles. Bentonite-cement mixes adapted to saline conditions are used, and post-intervention piezometric monitoring is installed.
Development of managed agricultural recharge zones: Filter strips and vegetated infiltration ditches (using native species such as Prosopis pallida and Typha domingensis) are installed in degraded plots or canal edges. These structures recover agricultural runoff, reduce pollutants, and promote controlled infiltration. They are monitored with soil moisture sensors, flow meters, observation wells, and portable weather stations.
Initial diagnosis (0–2 months): Remote analysis using satellite imagery and elevation maps to identify thermal anomalies, subsidence zones, runoff traces, and potentially abandoned wells. Soil reflectance, NDVI, and seasonal surface moisture changes are measured to generate a geo-referenced preliminary geochemical risk map.
Field inspection (2–4 months): Technical validation of the sites identified in the previous phase. Groundwater levels are measured using piezometric probes, and groundwater samples are analyzed for EC, chloride, nitrate, coliforms, and heavy metals. Each well’s structural condition is inspected and classified using a risk index.
Design and prioritization (3–5 months): A technical intervention plan is developed. Required infiltration rates are calculated, water balances modeled based on climatic and soil conditions, and wells are prioritized based on potential impact. Sealing materials (bentonite, cement, resin) and optimal geometries of infiltration ditches are defined.
Works execution (6–10 months): Hydraulic closure of prioritized wells is performed. Each intervention is documented with material volume, sealing mix type, depth, and date. Simultaneously, vegetated filter strips are constructed, and flow is measured using flow meters and pressure sensors in monitoring chambers.
Continuous monitoring (10–24 months): An automated piezometric sensor network is operated and connected to a real-time data visualization platform. Continuous measurement of EC, chloride levels, water table depth, and accumulated infiltration is performed. External audits are conducted quarterly, and results are reported through the Aqua Positive traceability system.
The in the Chira River Valley and Piura region emerges in response to an accelerated process of hydrogeological degradation that threatens agricultural sustainability, public health, and water resilience in this strategic region of northwestern Peru. The combination of intensive agriculture, outdated irrigation systems, and unplanned urban growth has led to critical overexploitation of the area’s coastal and fluvio-alluvial aquifers. Deep and semi-deep wells—many unlicensed and unmaintained—have disrupted the subsurface piezometric balance, allowing saline intrusion from both marine and deep mineralized zones.
The project area includes alluvial zones of the Chira River and tributaries across districts such as Sullana, Marcavelica, Las Lomas, La Huaca, and Piura. Practices like heavy agrochemical use and flood irrigation have triggered secondary salinization and diffuse contamination of groundwater. This is worsened by soil sealing from informal settlements and untreated domestic discharges.
In response, the project proposes a technically structured intervention: remote detection and hydrochemical characterization of critical wells, progressive hydraulic sealing of high-risk structures, and implementation of managed agricultural recharge areas using nature-based solutions. All actions follow the VWBA and WQBA frameworks, ensuring quantifiable and verifiable groundwater and water quality benefits.
Implementation spans five phases: remote diagnosis, field inspection and water quality testing, technical design and prioritization, execution of well closures and recharge structures, and continuous monitoring with IoT sensors, external auditing, and Aqua Positive traceability.
The intervention benefits the Bajo Chira aquifer and parts of Piura’s coastal system—zones identified by ANA as highly vulnerable. The project aligns with SDGs 2, 3, 6, 13, 15, and 17, supporting water access for irrigation, health, and sustainable production while restoring soil functions and fostering local governance. The validated, permanent, and traceable benefits can be monetized as Positive Water Credits (CAPs), replicable in similar hydrogen.
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