Aquifer Recharge Research Articles

HYDROCHEMISTRY AND SURFACE WATER - GROUNDWATER INTERACTIONS IN AN ANTHROPICALLY DISTURBED MOUNTAIN RIVER (SIERRAS PAMPEANAS, CENTRAL ARGENTINA)

The surface water - groundwater interactions in a small anthropically affected mountain watershed (Salsipuedes River) in the Sierras Pampeanas (central Argentina) were analyzed and quantified by means of 222Rn mass balance modeling, and its implications in hydrochemistry and water quality were examined. Surface waters, springs and groundwater were sampled during the 2021-2022 hydrological year, and the major dissolved composition was determined. The studied waters are alkaline, showing an evolution from medium mineralized (1.5 < ∑+ < 3 meq L-1) to mineralized type (3 < ∑+ < 6 meq L-1) downstream. In general, waters are of the bicarbonate - calcium type with no spatial or seasonal variations. This composition is mainly controlled by silicates weathering. 222Rn modeling indicates that near the headwaters the Salsipuedes River recharges the aquifer, losing 1.2% and 2.4% of its discharge during the dry and wet seasons, respectively. Downstream, the system changes its hydrological behavior and the river acts as a gaining stream; i.e, it receives groundwater inflow. The magnitude of this inflow varies seasonally, being greater in the wet season (1.5 - 2.2% of the total flow) than in the dry season (less than 0.25%) due to a rise in the water table level as a result of direct recharge of the phreatic aquifer. Anthropic influence is noticeable in nitrate and chloride concentrations, which are derived from domestic wastes and septic tanks. The highest concentrations of these ions in surface waters are found in the urbanized area, where the river stretch corresponds to a gaining stream, reflecting that even small amounts of groundwater inputs can alter the chemical composition of streams. A temporal analysis also showed a variable response of the system to the increasing anthropic pressure and climatic events such as ENSO, which affect not only water availability but also its quality, highlighting the vulnerability of small mountain watersheds.

Feasibility of Managed Aquifer Recharge in Southwest Kansas

Feasibility of Managed Aquifer Recharge in Southwest Kansas

Evaluation of groundwater travel time through a multilayered aquifer using multiple tracers and a novel transport approximation

AbstractAquifer long-term replenishment (ALTR) is a managed aquifer recharge (MAR) strategy by which reclaimed water is continuously delivered by injection wells to depleted, confined aquifer systems to increase groundwater storage and increase the potentiometric surface over space and time. One implication of large-scale continuous recharge is a large radial impact and the need to quantify transport in radially extensive strata. The use of an artificial tracer can be cost-prohibitive as the radial front moves further from the injection well. This investigation employs a novel approximation for radial transport to track the radial front of recharge, injectate constituents and simulation of tracer breakthrough concentrations under transient recharge rates, variable depth-dependent flow distributions over time, and variable influent concentrations. Six constituents—sulfate, chloride, total organic carbon (TOC), fluoride, 1,4-dioxane and N-nitrosodimethylamine (NDMA)—were chosen to evaluate conservative transport and semiqualitatively assess attenuation of nonconservative constituents relative to conservative tracers. Results indicate that sulfate acted as the most effective conservative tracer for characterization of transport and travel times at the study site. The analytical model was modified to account for variable operations at the MAR demonstration facility and was effective in simulating breakthrough curves over the period of performance, particularly sulfate concentrations at a monitoring well located 104 m from the injection well. The behavior of the remaining constituents is discussed, and the qualities of an effective intrinsic tracer for future ALTR projects are identified.

Head-Independent Infiltration Rate in Aquifer Recharge with Treated Municipal Wastewater

Head-Independent Infiltration Rate in Aquifer Recharge with Treated Municipal Wastewater

Managed Aquifer Recharge for Sustainable Groundwater Management: New Developments, Challenges, and Future Prospects

The combined effect of climate change and increased water demand has put significant strain on groundwater resources globally. Managed aquifer recharge (MAR) has become an effective approach for addressing groundwater depletion problems and sustainable management of groundwater resources. This review article provides an extensive insight into the existing knowledge of MAR, including the main objectives and applications, implementation techniques (surface spreading, sub-surface, and induced recharge) being practiced over the years, risks and challenges associated with the MAR, and the developments in the field of MAR. This review also explores the potential of MAR in the Friuli Venezia Giulia (FVG) region, north-eastern Italy. An average increase in temperature and a decrease in precipitation and piezometric levels in the region suggest the development of a proper MAR plan to manage water resources in the decades to come. Additionally, a comparative analysis of studies published over the last 20 years, focusing on the quantitative and qualitative aspects of water resource management, is conducted to analyze the research trends in the field of MAR. The reviewed literature reveals a notable research trend towards the quantitative aspect compared to the qualitative one. This review also identifies a notable disparity in qualitative studies during the analysis of water quality parameters considered in different MAR studies. Based on this review, a prospective viewpoint to address the challenges and expand the scope of the field is presented. This calls for an optimized strategy that considers both water quality and quantity issues, along with incorporating environmental and socio-economic aspects within the framework of MAR.

Mapping the Potential of Managed Aquifer Recharge in Africa: GIS-based Multi-Criteria Decision Analysis Approach

Africa faces numerous challenges related to rainfall variability, droughts, water scarcity, and climate change. Managed Aquifer Recharge (MAR)- groundwater recharge and underground water storage for later use or environmental support presents a viable alternative for water storage and may provide an effective tool for coping with such challenges. However, the potential area where MAR can be feasibly implemented has not been identified. This study mapped MAR feasibility using a Geographic Information System-based Multi-Criteria Decision Analysis (GIS-MCDA) and assessed MAR potential in Africa. The methodology focused on three key pillars of MAR feasibility: intrinsic suitability based on biophysical parameters, water source availability, and water demand. Maps responding to these pillars were developed and combined to create a composite MAR feasibility map. Results show that 18% of the continental area falls into the low feasibility class, 73% into the moderate feasibility class, and 7% into the high feasibility class. The feasibility map was validated against 17 existing MAR schemes in Africa, demonstrating a good correlation between their locations and areas with MAR potential. Results of sensitivity analysis of criteria weights of the biophysical parameters show that geology is the most influential criterion, followed by slope. In general, this first feasibility assessment shows good potential for MAR implementation in Africa. Therefore, MAR should be considered prominently among other water storage options for resilience building in Africa and policymakers should ensure adequate resource allocation for its implementation. The feasibility map can be used to guide MAR planning and investment decisions.

Hydro-chemical characterization of groundwater using multivariate statistics in Hawassa City, Southern Ethiopia

ABSTRACT This study characterized the hydro-chemical characteristics of groundwater for assessing the possibility of managed aquifer recharge in Hawassa City. A total of 48 water samples were taken from hand-dug wells and boreholes and examined to determine the water type, critical metrics, and key determinants of water quality. Multivariate statistical techniques such as hierarchical cluster, principal component, and linear discriminant analysis were used. The samples were divided into four variable groups and four case cluster groups. The results depicted the water hardness group (C1), soil salinity group (C2), weak and strong acids forming group (C3), and pollution indicator group (C4). Four water types were identified, Na–HCO3 and Ca–Na–HCO3 (87.5%), Ca–HCO3, and Na–Cl. Na–HCO3 was the dominant in hand-dug wells than in deep boreholes, which may account for evaporation or contaminations. Seven principal components with a cumulative variance of 78.58% were also formed. The first two, hardness and salinity, contributed 25.4 and 11.4% variance, respectively. In linear discriminate analysis, three discriminate functions with eight variables were generated, namely pH, K+, Na+, Ca2+, HCO3−, Cl−, BOD5, and COD. Thus, it is revealed that the decline in water quality attributed to natural and anthropogenic causes.

Hydrogeochemical Processes in Basement Areas Using Principal Component in Burkina Faso (West African Sahel)

The basement aquifers in Burkina Faso are increasingly exposed to groundwater pollution, largely due to socio-economic activities and climatic fluctuations, particularly the reduction in rainfall. This pollution makes the management and understanding of these aquifers particularly complex. To elucidate the processes controlling this contamination, a methodological approach combining principal component analysis (PCA) and multivariate statistical techniques was adopted. The study analyzed sixteen physicochemical parameters from 58 water samples. The primary objective of this research is to assess groundwater quality and deepen the understanding of the key factors influencing the spatial variation of their chemical composition. The results obtained will contribute to better planning of preservation and sustainable management measures for water resources in Burkina Faso. The results show that three principal components explain 72% of the variance, identifying anthropogenic inputs, with two components affected by mineralization and one by pollution. The study reveals that the groundwater is aggressive and highly corrosive, with calcite saturation. Water-rock interactions appear to be the main mechanisms controlling the hydrochemistry of groundwater, with increasing concentrations of cations and anions as the water travels through percolation pathways. PCA also revealed that the residence time of the water and leaching due to human activities significantly influence water quality, primarily through mineralization processes. These results suggest that rock weathering, coupled with reduced rainfall, constitutes a major vulnerability for aquifer recharge.

Best Management Practices to Mitigate Contamination of Karstic Aquifers from Emergency Fire-Control Runoff

We propose best management practices to increase karstic aquifer drinking water supplies’ resilience to potential hazardous material impacts where first responders and public safety officials suspect emergency firefighting runoff has entered the subsurface in the aquifer recharge zone. Karstic aquifers are unique because of their direct openings to the land’s surface, which allows contaminants in runoff or other surface waters to rapidly enter the subsurface and impact aquifer water quality. In the United States, 20% of the land surface is karst, and about a third of the groundwater used for drinking comes from karstic aquifers. Proposed best management practices emphasize on-site, real-time evaluation of the transport and fate of HAZMAT that may enter the subsurface and focus on water quality sampling, runoff and groundwater flow modeling, nontoxic dye tracing, and related studies for use in planning before and during an event and after emergency response has ended. We recommend best management practices for evidence-based screening of high-risk sites to facilitate placement of hazardous material sampling devices and emergency responder deployment. The best management practices, tools, curricula, and training described combine with earlier work by the authors to provide a comprehensive menu of actions to (1) help first responders prevent or limit flushing of hazardous material into a karstic aquifer; (2) help emergency management officials understand the consequences of contamination and issue data-driven geographically focused health and safety risk communications; and (3) help provide health and safety officials with relevant science- and data-based information that can help mitigate human and environmental health risks.

Integrated geophysical and geospatial techniques for surface and groundwater modeling

An integrated approach using geophysical and geospatial techniques was employed to model the surface and subsurface water-bearing strata and assess aquifer vulnerability in the Sehnsa town, Kotli district, State of Azad Kashmir, Pakistan. The inadequate scientific studies in the hilly terrain with such complex geological conditions has led to the failure of the boreholes for groundwater extraction. For the evaluation of groundwater potential and subsurface lithology, 30 vertical electrical soundings (VES) stations utilizing the Schlumberger electrode configuration were completed, modeled and analyzed spatially. Numerous geoelectrical parameters like true resistivity, thickness of subsurface layers and Dar-Zarrouk parameters were evaluated. The subsurface lithology delineated comprised topsoil, clayey sand, sandstone, and boulder clays which closely resemble to the borehole lithologs available in the study area. The inversion model confirms the presence of patches of high-resistivity sandstone in the southwestern part of the study area with the maximum thickness of the aquifer up to 140 m. Most aquifers were classified as unconfined with Q–type resistivity curves. The protective overburden capacity of the aquifers is rated as poor at VES 1, 3–5, 8, 10–16, 18, 19, 22–25, 27 and 30 whereas the moderate category was found at VES 2, 9 and 20 and excellent at VES 7 and 28, respectively. Therefore, the VES stations with poor and moderate ratings of overburden protective capacity are vulnerable for surface contaminants. The aquifer recharge was associated with rainfall and partly from the Poonch River. The effective integration of geophysical and geospatial techniques in this study provides sufficient information about the regional water resources and gives a preliminary model that can facilitate efficient water resource management in the area. These approaches can be successfully applied to diverse geographical and hydrogeological sites due to their versatility and reliability.

Health hazards from perchlorate enriched groundwater of a semi-arid river basin of south India and suggesting in-situ remediation through Managed Aquifer Recharge

The present study was conducted to assess the groundwater quality and perchlorate contents in the pre- and post-monsoon groundwater samples along with its associated health concerns with suggesting in-situ remediation in semi-arid Arjunanadi River basin of south India. Most of the samples (86 in pre-monsoon and 84 in post-monsoon out of total 94) showed secondary salinity and secondary alkalinity, and the perchlorate showed positive relations with Na+, K+, SO42-, Cl-, and NO3- contents. The main source of perchlorate could be fireworks manufacturing industries with 23 % of pre-monsoon (246.5 km2) and 33 % of post-monsoon samples (360 km2) showing perchlorate above the World Health Organization (WHO) standard (>0.07 mg/l). Perchlorate health risk assessment (PHRA) and total hazard index (THI) indicated more effect from oral pathway compared to the dermal pathway with about 80 %, 79 %, 65 %, and 60 % of samples causing health complications for infants, children, women, and men during the pre-monsoon. The post-monsoon groundwater showed increased health risks with 90 %, 82 %, 74 %, and 69 % of samples remaining hazardous for infants, children, women, and men. Artificial recharge through Managed Aquifer Recharge (MAR) techniques in the high-risk area could be useful to minimize the perchlorate contamination in groundwater and associated health risks under the United Nations Development Programme (UNDP) Sustainable Development Goals 3 and 6 (SDGs) for a healthy society.

Groundwater level rise and geological structure influences on land deformation dynamics: insights from managed aquifer recharge operations in Beijing, China

Groundwater level rise and geological structure influences on land deformation dynamics: insights from managed aquifer recharge operations in Beijing, China

Hydrogeophysical mapping of paleochannels for water security in Bhawanigarh Block, District Sangrur, Punjab, India

Paleochannels, ancient buried riverbeds, offer significant potential for groundwater management and contribute to achieving the Sustainable Development Goals (SDGs), particularly those focused on clean water (SDG 6) and sustainable ecosystems (SDG 15). These channels, formed when rivers change course due to natural processes or human activities, become filled with loose, permeable sediments like sand and gravel, making them natural reservoirs capable of storing large volumes of groundwater. This characteristic makes paleochannels invaluable for enhancing water security in arid and semi-arid regions.The present study, conducted in the Bhawanigarh block of Sangrur District, Punjab, focuses on mapping paleochannels for Managed Aquifer Recharge (MAR) using Electrical Resistivity Survey techniques. A total of 37 Vertical Electrical Soundings (VES) were performed with a Computerized Resistivity Meter, and the findings were validated using well-logging, exploration data, historical aerial photographs, and satellite imagery. Identifying and mapping these paleochannels enable targeted groundwater recharge efforts, enhancing the sustainable management of water resources.By strategically utilizing paleochannels for artificial recharge, excess surface water can be directed into these hidden reservoirs, effectively replenishing groundwater supplies. This approach supports agricultural and drinking water needs and strengthens resilience against climate change impacts, aligning with SDG 13 (Climate Action). Moreover, the careful management of these ancient channels promotes the sustainable use of natural resources, contributing to the overall goals of environmental sustainability and water security outlined in the SDGs.

Contextual and psychological factors in using recycled stormwater for residential purposes: a case study from Taiyuan, China

ABSTRACT This paper reviewed the managed aquifer recharge (MAR) practices around the world and explored urban residents' attitudes towards using stormwater recycled through MAR for residential uses in a Chinese socio-cultural context. The exploration was conducted from both contextual and psychological perspectives based on two established theories. The moderating effect of gender on residents' attitudes was tested. The results showed that most respondents supported using recycled stormwater for residential purposes but demonstrated hesitance in using recycled stormwater for uses that present proximity to human contact, which normally requires connecting the water to their house. Regarding the water quality attributes such as the colour, odour, and salt content of recycled stormwater, respondents were more tolerant if the water was used for uses that have limited human contact and less tolerant for uses that have close human contact. Therefore, any future decision to connect recycled stormwater into houses would require careful consideration and investigation as it depends on a range of issues including the proximity to human contact and the quality attributes of the water. Gender was a weak predictor in moderating respondents' attitudes towards using recycled stormwater, which adds to the inconsistent literature.

Examination of Water Use and Social Vulnerability: A Comparison of Four Communities in Alachua County, Florida

It is projected that about 30% of the world’s major cities will face severe water stress and urban drought from 2050 if climate change continues and has the anticipated effects (Florke et al, 2018; www.wrcwebsite.azurewebsites.net). Socio-economic drought, meaning water shortage in urban life, can have significant effects on a city’s inhabitants, including health and quality of life. Social and economic factors play an important role in planning and decision making of a society (Zhang et al, 2020). The analysis investigated the relationship between socio-economic factors and the use of potable water, its associated impact on aquifer recharge, and potentially identifying major factors influencing water demand and resource sustainability. The Centers for Disease Control and Prevention’s Social Vulnerability Index (SVI) and other measures were used for evaluating socio-economic factors. However, since SVI showed weak relationship with water use in the county and the neighborhoods, other socio-economic measures were assessed. Past research had found a correlation between water use and population, GDP, per capita income, electricity usage and irrigated land areas (Alacoma et al., 2007, www.usf.uni-kassel.de/watclim). Therefore, socio economic measures such as population density, household size, per capita income, and poverty rate and irrigation (with and without) potable water were analyzed to evaluate the relationship between water use patterns and these factors across the county and in the communities. The western communities had newer development and less parcels compared to the eastern with much older construction, which impacted their water use. Oakmont with separate reclaimed irrigation meter had lesser usage on potable water. Tioga on the other hand irrigated with potable water. Yearly SVI on a census tract level for the specific years of the study and other socio-economic measures such as population, per capita income, poverty, and household size were used in the analysis. The analysis was performed on four communities in Alachua County, Florida; two at the west and two at the east of the county. Socio-economic measures and physical features were evaluated for communities in the four locations to evaluate whether there is a relationship between water use patterns, spatial characteristics of development such as percent impervious and runoff, and measures of SVI. Spatial and basic statistics was used for this analysis. The western part of the county has had more intensive development in recent years compared to the eastern part of the county. The eastern communities have a high SVI and low potable water use per capita compared to the western communities. The number of households and population were the primary drivers of potable water use per census block. Percent impervious surface and runoff volume did not show any significant. relationship with a community’s SVI. At the parcel level, statistically significant differences were found between communities. For example, potable water use per parcel was lower in communities with high SVI. Keywords: water sustainability, urban water management, social vulnerability index, socio-economic factors, potable water use, aquifer recharge, reclaimed water use, runoff, imperviousness

Mobilization mechanisms and spatial distribution of arsenic in groundwater of western Bangladesh: Evaluating water quality and health risk using EWQI and Monte Carlo simulation

Arsenic (As) contamination in groundwater is emerging as a significant global concern, posing serious risks to the safety of drinking water and public health. To understand the release mechanisms, mobilization processes, spatial distribution, and probabilistic health risks of As in western Bangladesh, forty-seven samples were collected and analyzed using an atomic absorption spectrometer (AAS). The As concentrations in groundwater ranged from 1.97 to 697.4 μg L⁻1 (mean: 229.9), significantly exceeding recommended levels. The dominant hydrochemistry of As-enriched groundwater was Ca–Mg–HCO₃, with the primary sources of arsenic in groundwater being the dissolution of arsenic-bearing minerals in sediment and the recharge of aquifers from the Ganges River Basin. The assessment using the Entropy Water Quality Index revealed that the groundwater is unsuitable for drinking, with 89.36% (n = 42) of the samples surpassing the WHO's limit for arsenic. Rock-water interactions, including calcite dissolution and silicate weathering within the confined aquifer, predominantly influenced hydrochemical properties. The significant relationships among Fe, Mn, and As indicate that the reductive dissolution of FeOOH and/or MnOOH considerably contributes to the release of As from sediment into groundwater. Geochemical modeling analysis revealed that siderite and rhodochrosite precipitate into aquifer solids, suggesting a weak to moderate relationship among As, Fe, and Mn. The long residence time of groundwater, combined with the presence of a clayey aquitard, likely controls the mobilization of arsenic in the aquifer. For the first time, Monte Carlo simulations have been used in arsenic-prone areas to assess the severity of arsenic contamination in western Bangladesh. The analysis indicates that out of 100,000 people, 10 may develop cancer as a result of drinking arsenic-contaminated water, with children being more susceptible than adults.

Assessment of the impact of greenhouse rainwater harvesting managed aquifer recharge on the groundwater system in the southern Jeju Island, South Korea: Implication from a numerical modeling approach

Managed aquifer recharge (MAR) is increasingly being adopted worldwide to mitigate groundwater depletion and ensure the sustainability of water resources. Rainwater harvesting (RWH)-MAR can augment aquifer storage and reduce flood damage in rural areas with dense greenhouse facilities. This study has assessed the feasibility of greenhouse RWH-MAR in Namwon agricultural areas in the southern part of Jeju Island, South Korea, by considering the injection rate and location of MAR using a numerical model. The model results showed that groundwater level increases were directly related to the infiltration rate, although spatial differences in head rise were observed owing to the spatial variability of hydraulic conductivity. In addition, installing the RWH-MAR in highland areas (>100 masl) enhanced the water level rise when compared to the expected values, indicating that a higher hydraulic gradient and thick unsaturated zone facilitated more effective MAR outcomes than in lowland areas. To optimize the contribution of source water to the agricultural water demand, placing the RWH-MAR near the pumping well improved the availability of injected rainwater to agricultural wells. This study highlights the importance of designing RWH-MAR schemes considering MAR objectives and the topographic and hydrogeological characteristics of the site.

Hydroeconomic Optimization and Reoperation of Folsom Reservoir for Flood-Managed Aquifer Recharge Implementation

Hydroeconomic Optimization and Reoperation of Folsom Reservoir for Flood-Managed Aquifer Recharge Implementation

Identifying Groundwater Recharge Sources and Mechanisms using Hydrochemistry and Environmental Stable Isotopes in High Arsenic Holocene Aquifers of Bangladesh

Und erstanding the sources and mechanisms of aquifer recharge is critical for water resource management. So far, this is the first comprehensive study to explore the sources and mechanisms of groundwater recharge applying stable environmental isotopes and hydrogeochemical properties in Southwestern Bangladesh. Water samples from the different sources (groundwater, surface (pond), river and rain water) of high arsenic (As) Holocene aquifers were used to investigate the chemical tracers and environmental stable isotopes (δ18O and δ2H) to explore the hydrogeological features, groundwater recharge sources, mechanisms and processes. The analytical results showed high As concentration in water samples observed 590.7 μg/L. High As groundwater was identified by a low pH value, medium HCO3- and TDS with low concentration of NO3- and SO42-. However, depleted δ2H and δ18O signatures indicated that local vertical rainfall is the key source to recharge groundwater in study area. The recharge process from pond seepage and irrigation return flow also contribute in groundwater recharge. Isotopic signatures suggested the vertical connectivity amongst the aquifers and significant vertical recharge. The reduced heavier isotope reveals extra recharging from floods of mountains and high altitude. Due to the heterogeneous and anisotropic structure of the aquifer system the spatial variability of δ2H and δ18O shows limited lateral connectivity. The combined analyses of δ2H isotope and Cl- ion showed that evaporation is the primary cause for groundwater discharge. Based on the spatial and vertical recharge processes of groundwater, present study provides a crucial baseline knowledge for establishing a sustainable groundwater management strategy. The findings from this study can guide the development of targeted groundwater management strategies and improvement of understanding the groundwater recharge sources and processes.

Delineation of the Hydrogeological Functioning of a Karst Aquifer System Using a Combination of Environmental Isotopes and Artificial Tracers: The Case of the Sierra Seca Range (Andalucía, Spain)

The Sierra Seca aquifer system is located in the northeast (NE) of the province of Granada, in the Prebetic Domain (Betic Cordillera). It is composed of different aquifer units hosted in the Lower Cretaceous and Upper Cretaceous limestones. The two aquifers are separated by a low permeability marl layer, which effectively acts as a barrier between them. To outline the behavior of the hydrogeological system, 407 samples of precipitation and 67 samples of groundwater were obtained from May 2020 to Oct. 2022 and isotopically (δ18O and δ2H) analyzed. For the estimation of the recharge elevation, a new methodology has been applied to estimate the isotopic content of recharge as a function of precipitation. This allowed the evaluation of the vertical gradient of both precipitation (∇Zδ18OP=−2.9 ‰/km) and aquifer recharge (−4.4 ‰/km≤∇Zδ18OR≤−2.9 ‰/km). Therefore, estimating (1) the recharge zone elevation associated with the aquifer system, which is comprised between 1500 and 1700 m a.s.l., and (2) the transit time of recharge to reach the outflow point of the aquifer system, which varies between 4 and 5 months, is possible. Additionally, three tracer tests were conducted to outline the hydrologic connection between the recharge and discharge zones of the aquifer system. The results show that the Fuente Alta spring drains the limestones of the Lower Cretaceous, while La Natividad spring does the same with the limestones of the Upper Cretaceous. In the case of the Enmedio spring, groundwater discharge is related to infiltration through the streambed of the watercourse fed by the Fuente Alta spring.