The objective of this project is to restore the hydrogeological functionality and water quality of coastal aquifers located in the western strip of Guayas Province, especially in shrimp farming zones such as Balao, Naranjal, Tenguel, El Morro, and General Villamil. These areas form one of the country’s main aquaculture clusters and face a critical and progressive process of saltwater intrusion that threatens their operational continuity. This intrusion results from a combination of hydrodynamic and anthropogenic factors: a sustained piezometric decline caused by intensive groundwater use for shrimp pond recirculation, unplanned overexploitation of agricultural and industrial wells, and a reduction in effective recharge due to the loss of interior wetlands, degraded mangroves, and vegetated buffers that historically acted as natural retention and infiltration systems.
The hydric pressure imposed by these activities has reduced the natural hydraulic gradient that once served as a geohydraulic barrier to the advance of brackish water from estuaries and tidal channels toward continental aquifers. This loss of gradient has facilitated the inland migration of saline fronts through geological faults, contact zones between aquifers, and particularly through technically unsealed wells connecting water layers of varying quality.
In addition, extreme events such as storm surges or heavy rainfall with poor infiltration exacerbate this dynamic, accelerating the mixing of fresh and brackish waters and compromising not only the quality of the groundwater resource but also its strategic role as a supply source for rural consumption, crop irrigation, and overall coastal environmental resilience. As a result, there has been a significant inland advance of the saline front, already affecting productive water withdrawals and forcing increased treatment costs or the drilling of new, less productive, and more chemically vulnerable wells.
Abandoned or improperly sealed wells are one of the main vectors of vertical contamination in the coastal aquifer system. Without hydraulic isolation between layers, these wells allow upward or downward migration of brackish water, particularly during high tide events or prolonged pumping that reverses the gradient. This artificial connection between strata of different qualities degrades the freshwater column and exposes shallow aquifers to marine or anthropogenic ionic contaminants.
Additionally, there is a rapid loss of natural recharge zones such as mangrove forests, riparian buffers, and seasonal wetlands. Deforestation or their conversion into compacted surfaces reduces effective infiltration, alters the hydrologic balance, and diminishes the system’s resilience to drought or overextraction. This loss also limits the soil’s natural retention and filtration capacity, increasing surface runoff with contaminant load.
The uncontrolled expansion of aquaculture—particularly shrimp farms demanding large volumes of water for recirculation—has intensified pumping from coastal aquifers without an integrated water management framework. This intensive extraction, combined with the absence of land-use and water planning, places permanent pressure on the groundwater resource, favoring saltwater intrusion. Hydrochemical analyses conducted in the area show sustained increases in parameters such as electrical conductivity (EC), chlorides, exchangeable sodium, and sodium adsorption ratio (SAR), confirming the saline front’s advance and the progressive degradation of groundwater quality.
The project integrates multiple technical components that act synergistically to mitigate saltwater intrusion and restore the functionality of the coastal aquifer:
Detection of critical wells is performed initially via multispectral satellite analysis (Sentinel-2 and Landsat 8), complemented by drone-based LIDAR inspections and processing of vegetation indices (NDVI), surface moisture, and subsidence. This stage identifies abandoned wells, high-vertical-connectivity structures, and thermally anomalous zones indicating potential irregular activity.
Progressive technical well sealing is carried out using bentonite-cement mixtures and salt-resistant polymeric resins, depending on the lithological profile and depth of each well. Stage-wise sealing techniques are applied from bottom to surface to ensure hydraulic disconnection between strata and prevent saline migration. Each operation includes mechanical cleaning, geophysical profiling, and full documentation.
Creation of vegetated recharge strips is designed in marginal areas near canals or wet-dry transition zones. These strips incorporate halophytic species such as Avicennia germinans, Typha domingensis, and Sesuvium portulacastrum, which tolerate saline conditions and stabilize the soil. Infiltration ditches are built with gentle slopes, siliceous sand beds, and surface runoff control, simulating artificial wetlands capable of capturing and filtering rainwater and agricultural return flows.
Hydrochemical and piezometric monitoring is implemented with multiparameter sensors (EC, temperature, water table level, salinity) connected to IoT-based base stations. This network enables continuous readings, trend tracking in water quality improvement, and quantitative validation of benefits. The data is stored in interoperable platforms facilitating reporting to certifiers and water traceability entities.
All these actions align methodologically with the VWBA and WQBA frameworks, enabling robust accounting of induced recharge benefits (m³/year) and quality improvement (% reduction in EC and chlorides), with independent external audits and full digital traceability via Aqua Positive.
The project implementation is structured into five successive stages, each with specific technical objectives, applied technologies, and validated monitoring protocols.
Phase 1 – Remote Diagnosis (0–2 months): A comprehensive analysis using remote sensing technologies is conducted. Sentinel-2 satellite images and scheduled drone flights with multispectral sensors, thermal cameras, and LIDAR are used. Data are processed to identify subsidized zones, degraded vegetation, and unchanneled runoff paths. NDVI is calculated, SWIR reflectance is analyzed, and GIS layers on land use and well records are integrated. The result is a geohydrological risk map that establishes the spatial, hydrological, and climatic baseline.
Phase 2 – Field Validation (2–4 months): All previously detected wells are inspected, documenting their structural condition, vertical connection, and effective depth. Multiparameter sondes are used to measure in situ EC, water table level, temperature, and salinity. Water samples from at least three depths per well are collected for lab analysis of chlorides, bromides, nitrates, coliforms, SAR, and heavy metals. An integrated hydrochemical and structural risk index is created to prioritize interventions.
Phase 3 – Technical Design (3–5 months): Detailed technical profiles for each well are developed, including geophysical profiles and collected hydrogeological parameters. Suitable sealing mixtures are defined (bentonite-cement with antisaline additives or expanded resins), and potential water balances are modeled using historical rainfall (SENAMHI), return flows, and infiltration rates estimated via field permeameters. Recharge strips are designed with landscape-integrated features, halophytic vegetation, and structures like infiltration ditches, biofilters, and restored wetlands. KPIs include net infiltration rate (mm/day), retained water volume (m³), and expected EC reduction.
Phase 4 – Execution (6–10 months): Certified hydraulic well closures are performed. Wells undergo cleaning, continuous vertical profiling with geophones, and controlled staged injection of sealing material. Each closed well is documented with photos, coordinates, intervention depth, and materials used. Vegetated recharge strips are built with engineered hydraulic gradients; humidity and pressure sensors are installed in ditches and observation wells; and automated weather stations are deployed to record rainfall, temperature, and evaporation.
Phase 5 – Monitoring (10–24 months): An integrated IoT network includes multipoint piezometers, hydrochemical sensors, and dataloggers linked to a cloud platform. Continuous monitoring of key parameters (EC, chlorides, piezometric level, cumulative infiltrated flow, aquifer temperature) is conducted. Data are validated via bi-monthly laboratory sampling and compared against the baseline. Results undergo quarterly external audits and are reported under the Aqua Positive framework. This enables verification of VWBA benefits (effective induced recharge) and WQBA (quality improvement) with full traceability.
This project is a direct response to the hydrochemical and structural degradation affecting the southern coastal aquifer of the Daule-Peripa system in Guayas, Ecuador. The region, marked by intensive groundwater use for shrimp farming, advanced agriculture, and expanding urban consumption, faces sustained salinization driven by overexploitation and loss of coastal hydraulic gradient. Inactive, technically unsealed wells in critical interaction zones with brackish water bodies act as vertical conduits accelerating saline intrusion into freshwater aquifers, compromising agricultural water security and rural potable supply.
The project follows a comprehensive strategy under the VWBA and WQBA frameworks, structured into five operational phases that integrate advanced technologies, community participation, and scientific validation. From remote sensing and field inspections to the sealing of high-risk wells, construction of vegetated recharge infrastructure, and digital IoT-based monitoring, each step is designed to quantify and restore both volume and quality of the aquifer.
The initiative contributes to SDGs 2, 3, 6, 13, 15, and 17 by protecting agricultural and human access to sustainable water, reducing hydrochemical pollutants, enhancing climate resilience, restoring recharge ecosystems, and establishing multisectoral technical partnerships with verified traceability.
Ultimately, this project establishes a scalable, science-based model for coastal aquifer recovery in salinization-prone regions, ready to be integrated into voluntary water credit markets and regional adaptation strategies.
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