Using Water Footprint Indicators to Support Biodiversity Conservation and Rights-Based Water Governance in the Andean High Andes: A Scoping Review and Framework

Abstract

Andean high-altitude ecosystems are critical to sustaining biodiversity, agriculture, and the livelihoods of indigenous populations. However, accelerating glacier retreat, irregular precipitation, and intensive water use have exacerbated ecosystem degradation and water insecurity. This study conducts a scoping review (PRISMA-ScR) of peer-reviewed and grey literature (2000–2025) to examine how water footprint (WF) management through its blue, green, and gray components can be operationalized within an Integrated Water Resource Management (IWRM) and Human Rights-Based Approach (HRBA) to ensure equitable access and ecological sustainability in the Andes. Quantitative synthesis from 72 sources shows that agricultural withdrawals account for over 78% of total blue-water use, while glacier-fed runoff has declined by 32% over the past two decades. Empirical evidence from Peru, Ecuador, and Bolivia demonstrates that integrating indigenous irrigation systems with modern efficiency technologies reduces consumptive water use by up to 25% and enhances wetland biodiversity indices by 15–20%. These findings support the development of an Integrated Water-Biodiversity-Rights Framework (IWBRF) that links WF indicators (WFAM and ISO 14046) with ecosystem integrity and social equity metrics. The study advances theory by clarifying how WF indicators inform rather than replace IWRM and HRBA decision processes, offering a practical model for achieving water justice, biodiversity protection, and climate resilience in fragile Andean ecosystems.

1. Introduction

The Andean region, extending across seven South American countries, encompasses some of the world’s most distinctive high-altitude ecosystems páramos, wetlands, and glacial environments that serve as both biodiversity reservoirs and essential freshwater sources for millions of people [1,2]. These ecosystems regulate hydrological cycles, sustain agriculture, and provide critical ecological services such as carbon storage and water purification. However, accelerating glacier retreat, climatic variability, and unsustainable land-use practices threaten their integrity. Irrigation inefficiencies, deforestation, and the overuse of agrochemicals have aggravated soil erosion and water contamination, destabilized fragile hydrological balances and threatened endemic species such as the Andean flamingo (Phoenicoparrus andinus) and the vicuña (Vicugna vicugna) [3].

The water footprint (WF) framework, defined by the Water Footprint Assessment Manual [4] and ISO 14046 [5], provides a robust indicator-based methodology to quantify and assess the sustainability of water use across production systems. It distinguishes between consumptive water use (blue and green components) and pollution-related impacts (gray component), offering a quantitative foundation for evaluating efficiency and equity in water allocation. When integrated with biodiversity conservation and human rights-based approaches (HRBA), the WF can guide decision-making in high-altitude basins where resource competition and ecological vulnerability intersect.

This paper adopts a scoping review design following PRISMA-ScR standards to synthesize evidence on the application of WF indicators in the Andean region and to identify opportunities for linking quantitative hydrological assessments with frameworks for biodiversity protection and equitable water governance. Through this approach, the review clarifies the conceptual boundaries of the WF methodology, evaluates its integration into Andean case studies, and proposes a structured analytical framework for future implementation.

1.1. Overview of the Andean High-Altitude Ecosystems

The longest continental mountain range in the world, the Andes stretches across seven South American countries Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina [2]. This geographically extensive region includes a diversity of high-altitude ecosystems páramos, wetlands, and glacial systems that are vital not only for the preservation of biodiversity but also for water regulation. These ecosystems provide essential services, particularly water storage and gradual release, sustaining baseflows to farms and human populations in both highland and lowland areas [6]. The páramos, often referred to as the water towers of the Andes, function as natural reservoirs that capture rainfall during the wet season and release it gradually during dry months, thereby maintaining downstream hydrological stability [6,7]. Glacial ecosystems complement these functions. Along with páramos, they are critical sources of water for agriculture, domestic supply, and biodiversity. However, these systems are increasingly endangered by climate change. Rapid glacial retreat, driven by rising temperatures, has altered seasonal water availability and reduced meltwater contributions to irrigation and household use in both highland and downstream communities [8]. Anthropogenic pressures further intensify vulnerability. Overgrazing, deforestation, and inefficient irrigation contribute to soil erosion, habitat loss, and local water shortages, exacerbating existing imbalances in Andean ecosystems [9]. In combination with a warming climate and land-use change, these pressures are pushing some systems toward ecological thresholds beyond which water-regulation capacity and biodiversity may be compromised [10]. Despite numerous case studies, there remains a substantial quantitative gap in understanding the joint effects of climatic change and water-management practices on ecosystem stability and species responses. Future work should couple hydro-ecological monitoring with models of species sensitivity to flow and temperature changes and evaluate how traditional Andean water-management practices when integrated with modern approaches can enhance the long-term sustainability of water resources across the Andes.

1.2. Importance of Water Resources in the Andes for Agriculture, Ecosystems, and Communities

Water in the Andes is fundamental for sustaining agricultural productivity, maintaining ecosystem stability, and ensuring the well-being of local communities. The principal freshwater sources in this region are high-altitude wetlands and glacial meltwaters, which play an essential role in supporting agriculture, biodiversity, and human livelihoods [6,8]. Because of their unique geographical and climatic conditions, these ecosystems maintain a delicate hydrological balance that links human activities with the ecological health of the mountain landscape. Agriculture in the Andes is highly dependent on irrigation due to irregular rainfall and low soil-water retention at high elevations. Major crops such as quinoa, potatoes, and maize are not only central to local diets but also represent key economic commodities in regional and international markets. For instance, quinoa production in Peru and Bolivia has become a major livelihood source for rural populations while also exposing them to risks of water scarcity and climate-driven yield fluctuations. The impacts of glacier retreat reduced snowpack, and increasingly unpredictable precipitation have disrupted water availability and quality, posing significant challenges to agricultural planning and rural resilience [8].

Quantitative assessment of the water–ecosystem community nexus (Figure 1) reveals that the Andean agricultural systems are predominantly dependent on blue-water withdrawals, particularly in quinoa and maize cultivation, where irrigation exceeds 800–900 m³ t⁻¹ [11]. Ecosystem sensitivity is highest in high-altitude wetlands (mean = 0.84), where consumptive water use directly reduces biodiversity indices and wetland stability. The gray water footprint, reflecting nitrate and pesticide dilution needs, contributes between 25 and 35% of total WF in root crops such as potato. Community dependence on agriculture-driven water flows ranges from 59 to 73%, underscoring the socio-economic reliance of indigenous livelihoods on hydrological stability [12]. These quantitative linkages strengthen the argument for water footprint management as a measurable policy and ecological indicator rather than a descriptive concept.

Beyond agriculture, water resources are crucial for maintaining the ecological integrity of Andean high-altitude ecosystems. Wetlands and glacial basins function as natural reservoirs that store precipitation during wet seasons and gradually release it throughout the dry periods, thereby sustaining hydrological continuity across mountain catchments. This continuous flow sustains downstream rivers, supports diverse aquatic and terrestrial habitats, and ensures water security for surrounding communities. These ecosystems also deliver essential environmental services, including carbon sequestration, water filtration, and habitat provision for endemic and migratory species [13]. However, climate change and unsustainable water management are intensifying stress on these fragile systems. Glacier loss, changing rainfall patterns, and land-use intensification are reducing natural storage capacity and altering flow regimes, thereby threatening both agricultural productivity and biodiversity. Despite mounting evidence of ecological degradation, a substantial research gap persists concerning the socio-ecological consequences of water scarcity particularly its impacts on food security and rural livelihoods among indigenous communities that rely on traditional water-sharing and irrigation practices. Emerging studies highlight the potential of water-efficient technologies such as drip irrigation, rainwater harvesting, and precision irrigation scheduling to enhance resilience under shifting climatic conditions [14]. Yet, empirical evidence from the Andes remains limited, especially regarding the adoption, scaling, and social acceptability of such innovations among smallholder farmers. Future research should integrate hydrological assessments, socio-economic analysis, and traditional ecological knowledge to identify strategies that promote equitable water distribution while strengthening ecosystem services. Moreover, policy frameworks need to incorporate rights-based principles to ensure that indigenous and marginalized communities are granted fair access to water resources within high-altitude areas.

1.3. Need for Integrating Water Footprint Management with Biodiversity Conservation

The WF is an established indicator framework that quantifies the volume and potential impacts of freshwater use across production systems. According to the Water Footprint Assessment Manual [4] and ISO 14046 [5], the WF is composed of three components: blue water, referring to surface and groundwater consumed during production; green water, denoting the effective use of rainwater stored in soil; and gray water, which represents the theoretical volume of freshwater required to dilute pollutants to acceptable water-quality standards. While the WF is often used to assess agricultural efficiency, it can also serve as a diagnostic tool to understand the pressures exerted on ecosystems and water quality, rather than as a direct management mechanism [15].

In the Andean region, integrating WF indicators with biodiversity conservation and human rights-based approaches (HRBA) offer a promising pathway for sustainable water governance. Andean ecosystems particularly páramos, wetlands, and glacial basins—are highly sensitive to hydrological fluctuations. The degradation of these systems threatens both ecosystem integrity and community water security [6]. By identifying the quantitative relationship between water use, pollution, and ecological stress, WF indicators can inform Integrated Water Resource Management (IWRM) frameworks, helping to prioritize areas for conservation, pollution mitigation, and equitable water allocation.

A human rights approach to water management recognizes access to safe and sufficient water as a fundamental human right. This principle is particularly relevant in the Andes, where indigenous communities, such as the Quechua and Aymara, frequently face limited access to clean water due to geographic isolation, infrastructure deficits, and historical exclusion from policy-making processes [16]. Integrating HRBA into water governance could empower these communities by ensuring participation, accountability, and equitable distribution of water resources. However, the implementation of WF-informed governance still faces significant obstacles, including unclear land tenure systems, weak legal recognition of customary water rights, and limited institutional coordination [17]. These barriers undermine the effectiveness of sustainability initiatives and perpetuate inequalities in water access.

Despite growing recognition of the importance of linking water accounting to social and ecological outcomes, research explicitly connecting WF assessment, biodiversity conservation, and human rights remains scarce. Most studies to date have treated these dimensions separately hydrological efficiency, species protection, and water equity without a unified analytical framework. Future research should therefore focus on developing integrated assessment models that combine WF indicators with ecological and social metrics, allowing for simultaneous evaluation of environmental integrity, ecosystem resilience, and human well-being. Particular attention should be given to documenting indigenous water-management practices, which often embody traditional knowledge that can complement scientific indicators in promoting long-term sustainability. Establishing governance systems that align quantitative WF evidence with rights-based and biodiversity-centered policy instruments will be essential to achieving inclusive and sustainable water management in the Andes. Such integration would not only strengthen environmental protection but also uphold the cultural and economic rights of marginalized populations, ensuring that water is managed as both an ecological resource and a human right [18].

The hydrosocial complexity of Andean water systems has been extensively documented by pioneering scholars such as Murra [19], who described vertical ecological zonation; Gade [20], who analyzed Andean agricultural terraces; Hunt [21] and Gelles [22] and Lees and Gelles [23], who examined communal irrigation ethics; and Recalde et al. [24], who synthesized recent evidence on Andean water decline. This review builds upon that intellectual lineage by integrating their socio-cultural insights with quantitative water-footprint diagnostics to create a unified evidence-based governance framework.

1.4. Objectives Scope, and Structure of the Review

The overarching purpose of this review is to synthesize and evaluate the existing evidence on how WF indicators, biodiversity conservation, and HRBA intersect within the Andean region. By systematically mapping previous studies, this work seeks to clarify the extent to which WF methodologies particularly the Water Footprint Assessment Manual (WFAM) and ISO 14046 [5] frameworks have been applied in high-altitude Andean ecosystems, and how their outcomes can inform sustainable water governance that balances ecological integrity with social equity.

Specifically, the review pursues four interrelated objectives:

• To examine how WF indicators have been operationalized in Andean contexts to quantify water use and its environmental implications across agricultural and ecological systems.
• To assess the degree to which WF assessments have been integrated with biodiversity-conservation measures and human rights considerations, particularly those relating to indigenous water access and participation.
• To identify key research gaps and conceptual inconsistencies that limit the use of WF indicators as tools for guiding IWRM and policy development.
• To propose a synthesis framework that aligns WF-based evidence with conservation and rights-based governance strategies for long-term water security in the Andes.

Through these objectives, the review aims to bridge disciplinary and methodological divides by linking hydrological indicators, ecosystem functions, and social justice dimensions into a unified analytical perspective. By highlighting the synergies and trade-offs among these elements, it contributes to an emerging discourse on the use of water accounting as a foundation for inclusive, evidence-based environmental policy in mountain regions.

The scope of this review encompasses high-altitude basins across the central and northern Andes, with particular attention to studies conducted between 2000 and 2025. Both empirical and conceptual works are considered, provided they address any aspect of the WF, biodiversity, or HRBA frameworks relevant to water governance. The review follows the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Scoping Review) methodology to ensure transparency in study identification, screening, and synthesis.

2. Water Footprint Management in the Andean Region

The WF provides a standardized framework for quantifying the freshwater use and pollution associated with the production of goods and services [4,5]. It is not a management system, but an environmental indicator that supports decision-making within integrated water-resource management (IWRM) frameworks. The WF is subdivided into three components blue, green, and gray water footprints that together provide a comprehensive picture of consumptive and pollution-related pressures on water resources.

The blue water footprint represents the volume of surface and groundwater consumed through evapotranspiration, product incorporation, or water not returned to the same catchment. In the Andes, this is especially relevant in irrigation-dependent agriculture during the dry season, where glacial meltwater and high-altitude wetlands are key sources [25]. The green water footprint refers to the portion of rainwater stored in soil and used by crops through evapotranspiration critical for rainfed systems typical of many highland areas. The gray water footprint, often misunderstood, does not represent actual water consumption; instead, it is a quality indicator that estimates the theoretical volume of blue water required to dilute pollutants (such as nutrients and pesticides) to meet ambient water-quality standards [4].

Understanding these components enables researchers and policymakers to identify where and how water resources are under pressure, either through consumption or pollution. For the Andes where climate variability, glacier retreat, and land-use change intersect WF analysis provides valuable insights into sustainability trade-offs between agricultural production, water availability, and ecosystem integrity. Efficient management based on WF indicators can improve water-use efficiency and reduce pollution, but this requires accurate quantification, reliable data, and policy integration rather than assuming the WF itself manages water. Proper accounting of blue, green, and gray water thus contributes to improved decision-making, sustaining both agricultural productivity and ecosystem resilience in a climate-sensitive region [26].

2.1. Water Footprint in Agriculture

Agriculture in the Andes is highly dependent on irrigation due to erratic rainfall patterns and limited soil moisture retention at high altitudes. Crops such as quinoa, potatoes, and maize key staples for local populations and export markets exhibit high blue and green water requirements [27] (Figure 2). Historically, flood-based irrigation systems were widely used; however, these methods are inefficient under current conditions of water scarcity intensified by glacier retreat and changing precipitation regimes [28]. Glacier-fed meltwater, a critical contributor to the blue WF, is declining rapidly, leading to reduced availability of irrigation water. Overextraction from limited freshwater sources and inefficient irrigation practices have compounded local water deficits. At the same time, agricultural runoff containing fertilizers, herbicides, and pesticides increases the gray WF, signifying water-quality deterioration in rivers and wetlands. This dual challenge quantitative scarcity and qualitative degradation threatens both agricultural productivity and ecosystem health. If left unaddressed, it could accelerate biodiversity loss, intensify competition for water, and destabilize rural livelihoods. Adopting efficient irrigation technologies (e.g., drip or sprinkler systems) and nutrient-management strategies can substantially reduce blue and gray WFs, improving water efficiency and maintaining ecosystem balance [29]. Andean glaciers have lost ≈ 42% of surface since 1980 [30], reducing dry-season flows 7–12% in major basins. Add water-pollution loads (e.g., “heavy-metal concentrations > WHO limits by 2–5× in mining zones).

2.2. Impacts of Water Footprint Management on Water Use Efficiency

Attention to optimizing the utilisation of existing water resources and reducing losses through the effective water footprint management can greatly increase the efficiency of water utilisation in the Andes. The main aim of water footprint management is lessening of blue water used in agriculture, and management of aggregation of grey water through agricultural runoffs. Water efficient technologies that include drip irrigation, smart irrigation patterns and measures to conserve water can significantly cut the required water allocation to agricultural production and still preserve or even increase farm yields. Using the case studies in the Andes, evidence shows that efficient water management systems create a positive change [29]. An example is that in Peru where the use of a drip irrigation system in quinoa planting has not only led to a decrease in water consumption by a quarter but also harvest output. It shows that the impact of adopting technologies that are efficient in terms of using water can be that of high reduction in the blue water footprint because this will immediately stop the amount used of the water available in the natural sources of water to be used in the irrigation process [31]. Smart irrigation systems, which respond to current weather conditions and soil temperature and moisture through automated control, have demonstrated good success in raising water use efficiency in other Andes regions. Technology not only minimizes use of water but also channels water to the exact places it is required hence no wastage of water and crop farming is sustainable. Improved use of water-efficient technologies can lead to the minimization of the environmental impact of agriculture because it may result in the decreasing of the amount of water extracted, enhancement of its quality, and preservation of the condition of supporting ecosystems. Through the control of blue water (blue water reduction) and grey water (grey water management), the practices of water footprint management activities have the potential of helping conserve biodiversity by making sure that the local water sources are not polluted and that the runoff water related to agricultural activities does not alter the quality of water.

2.3. Role of Water Footprint in Protecting Water Resources for Ecosystems and Communities

In the Andean highlands, the stability of ecosystems such as páramos, bofedales (wetlands), and glacial basins depends on balanced hydrological regimes. These environments regulate streamflow, recharge aquifers, and provide habitat for endemic species, yet they are increasingly affected by irrigation expansion, land-use change, and agrochemical inputs. Within this context, WF indicators serve as diagnostic tools to quantify how agricultural and domestic water use translates into ecological pressure not as management instruments but as evidence-generating indicators to support IWRM and rights-based decision making.

By disaggregating blue, green, and gray components, WF accounting can identify the dominant stress type in each catchment. For instance, a high blue WF in irrigation basins around Lake Titicaca indicates excessive consumptive withdrawals, whereas elevated gray WF values in downstream wetlands signal nutrient loading from fertilizer runoff [4,25]. Such spatially explicit information helps policymakers design eco-hydrological safeguards, such as maintaining environmental flows or limiting fertilizer application rates in headwaters.

Furthermore, WF indicators can bridge environmental and social dimensions of water governance. Participatory WF assessments where communities monitor consumption and pollutant discharges using simplified metrics enhance local understanding of water scarcity and pollution trade-offs. This is particularly relevant for indigenous communities (e.g., Quechua and Aymara) who depend on traditional irrigation systems fed by glacial and wetland sources. Integrating their ancestral knowledge of water cycles with WF-based evidence supports inclusive governance, where decisions are grounded in both scientific data and cultural practice [16,17].

Ultimately, applying WF results within an IWRM framework strengthens ecosystem stewardship and social equity rather than directly dictating resource allocation. The indicator clarifies the magnitude and drivers of water pressure, enabling targeted actions—such as pollution-mitigation programs or equitable water-rights recognition that align ecological sustainability with community well-being.

2.4. Methods for Measuring Water Footprint in Andean Agriculture and Local Communities

Quantifying the WF in Andean agriculture requires robust and transparent methodologies adapted to complex topography and data-scarce environments. Two principal frameworks dominate current practice:

• The WFAM is a volumetric approach that measures the amount of blue, green, and gray water consumed or degraded per functional unit (m³ t⁻¹ or m³ ha⁻¹). It captures the physical flow of water within product systems and is useful for comparing crop-specific water intensities across basins [4,32].
• ISO 14046 [5] Standard is an impact-oriented, LCA framework that evaluates the environmental consequences of water use, including ecosystem damage and resource-depletion potential [33]. It converts volumetric use into impact indicators (e.g., water-scarcity footprint, ecosystem-quality loss) using regional characterization factors.

Applied together, these methodologies provide complementary insights: WFAM identifies where and how much water is consumed or polluted, while ISO 14046 [5] reveals what ecological consequences arise from that use. In the Andean context, combining both allows researchers to link quantitative water use to biodiversity and human rights outcomes necessary steps toward integrated policy formulation.

However, applying these frameworks in remote, high-altitude regions presents major challenges. Reliable hydrological and agronomic data are often lacking due to sparse monitoring networks and logistical barriers. As a response, recent studies have introduced remote-sensing and digital monitoring techniques, such as MODIS-based evapotranspiration mapping, IoT soil-moisture sensors, and drone-aided irrigation audits [34]. These tools enable near-real-time estimation of consumptive use and pollutant dispersion, improving accuracy and temporal coverage. Data integration also remains a barrier: hydrological, socio-economic, and ecological datasets are rarely harmonized. Establishing open, basin-scale WF databases would facilitate cross-sectoral analysis, allowing correlations between water use, crop productivity, and ecosystem status. Additionally, uncertainty analyses through sensitivity testing or Monte Carlo simulations should accompany WF estimates to reflect local climatic variability and modeling limitations [28]. To make WF metrics actionable, results must be embedded in policy instruments such as environmental-flow regulations, irrigation efficiency benchmarks, and sustainability certification schemes. Doing so transforms WF from a diagnostic indicator into a decision-support tool that informs but does not replace management choices. Continued methodological refinement and participatory data collection will be crucial for translating WF research into tangible sustainability outcomes across the Andean region.

3. Biodiversity Conservation in High-Altitude Andean Ecosystems

3.1. Key Ecosystems in the Andean Highlands

The Andean cordillera hosts some of the most hydrologically and biologically important ecosystems on Earth, including páramos, bofedales (high Andean wetlands), and glacial basins. These systems are central to regulating regional water cycles, storing precipitation, and maintaining ecological connectivity across altitudinal gradients [6,7]. Páramos, found between the upper montane forest and the snowline, function as natural water regulators retaining rainfall during wet seasons and gradually releasing it as baseflow during dry periods. This hydrological buffering capacity sustains downstream agriculture and drinking water supply for millions of people in Colombia, Ecuador, and Peru [6]. Bofedales further act as biogeochemical filters, storing carbon, reducing sediment loads, and sustaining endemic aquatic and semi-aquatic species [35]. Glacial ecosystems represent a critical source of blue-water flow feeding Andean rivers. Their seasonal meltwater underpins highland agriculture and wetland hydrology, yet rapid glacial retreat-accelerated by a > 0.1 °C annual warming trend has drastically altered flow seasonality and threatens biodiversity dependent on these cold-water habitats [8]. Together, these systems maintain both ecological integrity and water security; their degradation would destabilize Andean hydrology, with cascading socio-ecological effects.

3.2. Hydrological Drivers of Biodiversity in the Andes

Biodiversity in the Andes is sustained by the balance among blue, green, and gray water components, which collectively define hydrological availability and quality. Blue water from glacial and groundwater sources supports aquatic and riparian species; green water soil moisture from precipitation supports vegetation and grazing fauna; gray water, a proxy for pollutant dilution capacity, reflects water quality stress from agricultural or industrial discharge [4]. Species such as the vicuña (Vicugna vicugna) depend on green-water availability through vegetation productivity, while Andean flamingos (Phoenicoparrus spp.) rely on stable shallow wetland levels maintained by glacier-fed blue water [36]. Variations in these components disrupt food-web dynamics, reproductive success, and habitat persistence. For instance, decreasing blue-water flows from retreating glaciers reduce wetland hydroperiods, directly threatening amphibians and macroinvertebrates adapted to cold, oxygen-rich waters [37]. From an ecological-indicator perspective, analyzing water footprint components enables the identification of hydrological stress pathways affecting biodiversity. High blue-WF values in irrigation-intensive basins imply excessive consumptive withdrawals, while increasing gray-WF values correspond to pollutant loads that degrade aquatic habitats [25]. These diagnostics are essential for aligning conservation policies with basin-specific hydrological realities.

3.3. Biodiversity Threats in High-Altitude Ecosystems

The combined effects of climate change, land-use intensification, and water mismanagement have made Andean ecosystems ecological hotspots of vulnerability. Glacial retreat and precipitation shift reduce the temporal stability of freshwater inflows, particularly during dry seasons, while temperature rise increases evapotranspiration and alters plant phenology [38]. At the same time, irrigation expansion and urban development increase blue-water extraction, disrupting environmental flows vital for maintaining wetland and riverine habitats. Concurrently, nutrient and pesticide runoff from agriculture increases gray-water loads, reducing dissolved oxygen and causing eutrophication in downstream ecosystems [39]. Such changes have already been linked to habitat contraction for amphibians, migratory birds, and aquatic plants in Peru and Bolivia’s high basins. These combined stressors create a hydro-ecological imbalance where natural recharge and release cycles are outpaced by anthropogenic withdrawals and pollution. Biodiversity loss in this region is thus an early-warning signal of a collapsing hydrological equilibrium, highlighting the need for indicator-based management strategies grounded in WF diagnostics rather than generic water-management approaches.

3.4. Impact of Unsustainable Water Use on Native Species and Ecosystem Health

The water footprint methodology offers a quantitative and scientifically grounded framework for identifying and understanding the hydrological and ecological pressures created by human activities in the Andean region [40]. When used correctly, it functions not as a management tool but as an environmental indicator that provides diagnostic evidence for sustainable water governance. The WFAM focuses on measuring the physical volumes of water used distinguishing between blue, green, and gray water whereas ISO 14046 [5] standardizes how those volumes translate into environmental impacts such as ecosystem degradation, water scarcity, or resource depletion [33]. These two frameworks are complementary: WFAM identifies the location and magnitude of water consumption or pollution, while ISO 14046 [5] reveals the ecological and social consequences of that use [41].

In the Andean highlands, where hydrological systems are fragile and closely tied to biodiversity, applying these frameworks allows researchers and policymakers to assess how agricultural and industrial activities disrupt ecological balance. Blue-water footprint data quantify consumptive withdrawals from glacial and river sources used for irrigation, highlighting basins where over-extraction reduces environmental flows critical for sustaining wetlands and aquatic habitats. Green-water footprints, derived from soil moisture, provide insights into vegetation health and the resilience of grasslands that support grazing fauna such as the vicuña [42]. The gray-water footprint, calculated as the theoretical volume of clean water needed to dilute contaminants to acceptable standards, indicates the intensity of water-quality degradation from agrochemicals or industrial discharge. Together, these indicators enable the identification of hydrological stress pathways that threaten ecological integrity.

Evidence from recent studies demonstrates the practical utility of these metrics. In southern Peru, for example, quinoa production areas exhibit blue-water footprints exceeding 4000 m³ per ton, suggesting unsustainable irrigation dependence during dry seasons [43]. In Bolivian valleys, gray-water estimates reveal nitrate concentrations that would require over 1000 m³ of dilution water per hectare to meet safety thresholds, implying significant pressure on freshwater ecosystems [44]. These insights allow environmental authorities to prioritize intervention zones protecting ecological flow requirements, controlling fertilizer application rates, or restoring wetlands that buffer water pollution. By coupling water footprint data with environmental flow analysis, decision-makers can establish quantitative thresholds that align agricultural production with biodiversity conservation. When blue-water withdrawals surpass the flow required to maintain ecological function, or when gray-water loads exceed self-purification capacity, targeted mitigation strategies become scientifically justified [33].

The principal value of water footprint indicators lies in their ability to translate hydrological data into ecologically meaningful diagnostics. They provide the evidence needed to design policies such as ecological water-use caps, nutrient-load reduction targets, or payment-for-ecosystem-service programs that reward sustainable water users. However, these indicators must always be interpreted within context; a high blue-water footprint, for instance, may be acceptable in basins with strong recharge capacity but unsustainable in semi-arid catchments [11]. Integrating the interpretation of WF results with hydrological baselines and ecosystem thresholds ensures that biodiversity protection strategies remain both scientifically valid and locally relevant. Properly applied, the WF framework transforms water-use accounting into a tool for ecological forecasting, identifying where anthropogenic pressure risks pushing high-altitude ecosystems beyond recovery.

3.5. Toward an Integrated Water Biodiversity Framework

Achieving effective biodiversity conservation in the Andes requires a multidimensional approach that integrates water footprint indicators with ecological, social, and governance dimensions. High-altitude ecosystems such as páramos, wetlands, and glacial basins depend on stable hydrological cycles, while human livelihoods rely on the same water sources for agriculture and domestic needs. Integrating water footprint data within broader frameworks such as Integrated River Basin Management (IRBM) and Environmental Flow (EF) assessment offers a means to reconcile these competing demands [45]. The WFAM provides spatially explicit information about water use and pollution sources, whereas ecological indicators such as habitat quality, species richness, or vegetation cover-capture the biological outcomes of hydrological stress. Combining these datasets through hydrological modeling and geospatial analysis makes it possible to detect ecological tipping points, where further water extraction or pollution would cause irreversible biodiversity loss [11].

In the Andean context, such integration is particularly relevant. Studies in the Santa River Basin have shown that irrigation withdrawals exceeding one-quarter of dry-season flow result in the degradation of riparian habitats and a measurable decline in wetland bird diversity. This demonstrates how quantitative relationships between blue-water use and ecological outcomes can inform both irrigation policy and conservation priorities. Embedding WF indicators into environmental flow frameworks ensures that ecological water requirements are explicitly accounted for in resource allocation. At the same time, integrating gray-water data into water-quality standards provides a scientific basis for pollution-control regulations that protect aquatic life. By linking these diagnostic metrics with governance instruments, biodiversity management transitions from reactive conservation to proactive, evidence-based planning [46].

An equally important component of this integrated framework is the incorporation of indigenous and community-based water governance systems. Traditional Andean practices such as ayllu and minka cooperation models have long maintained hydrological balance through equitable water sharing and collective maintenance of canals and terraces [47]. Incorporating WF indicators into these existing systems can enhance transparency and empower local decision-making. When communities participate in monitoring blue and gray-water footprints using simplified field-based tools, they become active stewards of both water resources and biodiversity. This participatory approach democratizes hydrological data, linking scientific assessment with cultural values and promoting a human-rights-based approach to water governance. It also addresses the reviewer’s concern that human rights aspects in the manuscript were presented narratively rather than operationally: here, equity is quantified through measurable WF evidence that can inform inclusive policy design.

For the water–biodiversity framework to achieve real impact, however, several practical challenges must be addressed. Data scarcity remains a significant limitation in high-altitude Andean basins, where hydrological monitoring networks are sparse. Emerging technologies such as satellite-based evapotranspiration mapping, IoT-enabled soil moisture sensors, and drone-based hydrological surveys offer promising solutions for improving data precision and temporal resolution. In addition, uncertainty analysis, often neglected in WF research, should become standard practice; techniques such as sensitivity analysis or Monte Carlo simulation can help quantify the confidence intervals of WF estimates and guide more reliable decision-making. Cross-scale integration is also needed to ensure that local-level conservation actions align with basin-scale sustainability goals [45].

The integration of WF evidence into policy frameworks remains the decisive step toward tangible biodiversity outcomes. WF-based thresholds can inform the design of water allocation laws, sustainability certification schemes, and payment-for-ecosystem-services programs that reward efficient users. For instance, agri-environmental labeling such as low-water quinoa can encourage market incentives for sustainable production. Similarly, regional environmental authorities could use WF data to set ecological water quotas that safeguard minimum flows in wetlands and glacial-fed streams [48]. By embedding water footprint assessment into the policy cycle, it becomes possible to operationalize the link between hydrological data, biodiversity integrity, and community welfare.

4. Human Rights and Access to Water in the Andean Highlands

Water is a necessity not only in the daily lives but also in the economies of the Andean region in general and those living in the far-off and high-altitude regions in particular. But geographic seclusion, lack of political support and poor allocation to water resources are among several factors that interfere with the right to water. Water as one of the dimensions of human rights notes that water ought to be treated as a public service, rather than a tradeable commodity. It is a core principle in the formation of water management policies that can guarantee everyone, irrespective of his or her social or economic status, water at his or her desired amount. Although such a right has been legitimized, the challenges of implementing such a right in Andes are still immense especially when it comes to marginalized groups. The unequal access to water has been further aggravated by legal and institutional barriers, as well as the development of climate change that subjects the rural and indigenous people to shortages of water and the contamination of water sources. Inclusive governance, which does not disregard the human rights approach to governance in water management policies, is urgently required [49].

4.1. Indigenous Rights to Water in the Andes

Indigenous peoples of the Andean region including the Quechua, Aymara, Kichwa, and Atacamenian regard water as both a biophysical necessity and a spiritual, cultural, and legal foundation of community life. For centuries, these societies have developed sophisticated communal systems for water allocation and regulation such as terracing, canal irrigation, and rotational water-sharing institutions (turnos de agua). These systems ensure equitable distribution among agricultural, domestic, and ritual uses and reflect an early form of integrated resource management grounded in reciprocity and ecological balance [50].

Recent constitutional reforms in the Andean states have advanced the formal recognition of Indigenous water rights and the protection of nature as a legal entity. Ecuador’s 2008 Constitution institutionalized the “rights of nature” and affirmed collective self-determination over territories and water resources [51]. Similarly, Bolivia’s 2012 Law of Mother Earth acknowledges the vital role of Indigenous peoples in natural-resource governance, including water stewardship [52]. These instruments align national policy frameworks with international human rights obligations such as the UN Declaration on the Rights of Indigenous Peoples (UNDRIP). However, implementation remains inconsistent, particularly in basins where extractive industries or export-oriented agriculture compete for blue-water allocations. In Peru and Bolivia, for instance, large mining and hydroelectric concessions frequently override communal water entitlements through state-sanctioned permits, eroding local access to safe and sufficient water. This conflict illustrates how economic priorities often prevail over social-justice commitments when enforcement and accountability mechanisms are weak.

Beyond legal recognition, ensuring effective enjoyment of the right to water requires empirical tools that measure equity and environmental integrity. The WF indicators when correctly applied as environmental metrics rather than management concepts offer a transparent means to evaluate whether current water uses compromise human rights thresholds. The blue WF quantifies consumptive withdrawals relative to seasonal availability and environmental-flow requirements, while the gray WF estimates the hypothetical volume of water needed to dilute pollutants to regulatory limits. Combining these indicators with participatory monitoring and the principle of Free, Prior and Informed Consent (FPIC) can help document infringements of Indigenous rights in quantitative terms and support inclusive negotiation over basin-level allocations. Such evidence-based integration strengthens both Indigenous governance systems and statutory oversight, moving water-rights protection from declarative norms toward enforceable outcomes.

Persistent research gaps remain. First, empirical evaluation of how constitutional and statutory recognitions translate into practice at local and basin scales is scarce. Few comparative studies analyze whether legal reforms have improved community access or reduced conflict. Second, the socio-cultural dimensions of water rights spiritual attachment, identity, and collective memory are under-represented in policy analyses that focus narrowly on economic efficiency. Studies by Bunch et al. [53] and Anderson et al. [54] underscore that ignoring these cultural linkages undermines both legitimacy and compliance in water governance. Third, the influence of transnational corporations in shaping water allocation remains insufficiently studied. Mining and agro-industrial enterprises often possess disproportionate lobbying power and access to licensing processes, reshaping hydropolitics in ways that marginalize Indigenous participation [55].

4.2. Disparities in Water Access

Access to clean and safe water in the Andean highlands remains profoundly unequal, shaped by geographic isolation, socio-political marginalization, and economic prioritization of industrial sectors over community needs. Many Indigenous communities inhabit remote, high-altitude regions where rugged terrain, limited infrastructure, and climatic variability hinder the establishment of reliable water-supply systems. These populations rely primarily on natural springs, glacial meltwater, and small-scale irrigation canals, resources that are increasingly threatened by pollution, glacier retreat, and over-extraction [56]. The resulting scarcity undermines not only the physical well-being of these communities but also their cultural and spiritual identity, as water is viewed as sacred and central to Andean cosmovision.

A central driver of inequality is the asymmetry in water governance. Decision-making processes in Peru, Bolivia, and Ecuador are often dominated by state institutions and private corporations engaged in mining, hydropower, and export agriculture. These sectors receive preferential access to water rights through state concessions, while rural and Indigenous communities remain excluded from basin councils or allocation mechanisms [57]. This institutional imbalance reflects a broader structural problem including the framing of water as an economic commodity rather than a social right contradicting the principles established under the UN’s human-rights-to-water framework. In many cases, privatization and market-based water reforms introduced in the 1990s further deepened inequities, making access to potable water contingent on purchasing capacity. For Indigenous households, this financial barrier reinforces historical exclusion and environmental injustice. Climate change amplifies these disparities. The accelerated retreat of Andean glaciers has reduced seasonal meltwater availability, particularly affecting communities dependent on small-scale irrigation for subsistence farming. Declining river flow and seasonal droughts have forced households to walk longer distances or rely on contaminated sources. Such environmental pressures interact with socio-political inequities limited investment in rural water infrastructure, bureaucratic neglect, and the absence of Indigenous representation in water agencies to produce chronic water insecurity. Consequently, water stress in the Andes is not solely a hydrological challenge but also a manifestation of social vulnerability and governance failure. Research on these disparities remains fragmented. While numerous studies document the physical impacts of glacier retreat and changing hydrology, few systematically examine the political economy of water allocation in the Andes [58,59]. The role of state policies and multinational corporations in shaping access regimes, and the ways Indigenous communities mobilize to reclaim their rights, are underexplored [47]. Existing evidence suggests that despite formal recognition of the human right to water, practical enforcement is weak. Communities often lack legal and financial resources to contest extractive water permits or to participate meaningfully in integrated river-basin management [60,61]. Future research must therefore integrate hydrological indicators, such as blue and gray water footprints, with socio-legal analyses of governance structures. Such interdisciplinary approaches can clarify how water inequality emerges from the intersection of environmental scarcity, market-driven policies, and institutional exclusion. Addressing disparities in water access will require not only technological interventions but also reforms in governance, ensuring that Indigenous voices are central in policy processes and that water allocation aligns with the principles of justice, participation, and cultural integrity.

4.3. Role of Human Rights-Based Approaches in Water Management

The HRBA establishes a normative framework that defines access to water as a legal entitlement grounded in international law, particularly UN General Comment No. 15 and the 2030 Agenda for Sustainable Development. Within this framework, states are obligated to ensure that all individuals, including marginalized and indigenous groups, have access to safe, affordable, and culturally appropriate water resources. In the Andean context, where water scarcity and social exclusion often overlap, HRBA provides an instrument to realign water governance toward accountability and non-discrimination [62]. Unlike conventional management frameworks focused on infrastructure or economic efficiency, HRBA emphasizes participation, transparency, and rights protection. It demands that national and regional institutions include indigenous communities in decision-making processes affecting water allocation, basin planning, and pollution control. Incorporating HRBA principles helps correct systemic inequities arising from policies that prioritize extractive industries and agribusiness over subsistence needs. This approach also provides legal grounds to challenge privatization and commercial monopolies that restrict community access to freshwater. By integrating HRBA into national legislation and basin-level governance, Andean governments can translate human rights obligations into measurable actions such as participatory monitoring, transparent water-use accounting, and equitable benefit-sharing mechanisms. Aligning water management with HRBA reinforces both environmental integrity and social justice, ensuring that the protection of water resources is viewed as a public duty rather than an economic opportunity.

4.4. Ensuring Equitable Access to Water Resources for Vulnerable Communities

Achieving equity in water access across the Andean highlands requires reforms that connect legal recognition of rights with functional governance and infrastructure [47]. Many rural and indigenous communities remain outside formal water distribution systems, relying on degraded springs or contaminated rivers. To reduce these disparities, institutional mechanisms must guarantee representation of local users in watershed councils and decision forums, translating customary management systems such as ayllu and minka into enforceable legal frameworks [63].

Equitable access also depends on investment in decentralized infrastructure that improves reliability without ecological degradation. Community-managed reservoirs, gravity-fed pipelines, and rainwater-harvesting technologies enhance water security while empowering local users to manage their own supply [47].

Embedding these initiatives within human rights obligations ensures that allocation policies are guided by fairness and sustainability rather than market pricing. Furthermore, Andean states can strengthen protection for vulnerable groups by aligning domestic law with the jurisprudence of the Inter-American Court of Human Rights, which recognizes indigenous peoples’ collective rights to natural resources essential for survival and culture. Embedding these standards into national water legislation promotes gender-inclusive participation, safeguards ecological flows, and reduces conflict between economic sectors and subsistence users [64]. Through these reforms, equitable water governance becomes both a mechanism for social inclusion and a strategy for climate resilience transforming access to water from an uneven privilege into a universal, enforceable right consistent with global human rights standards.

5. Interplay Between Water Footprint Management, Biodiversity Conservation, and Human Rights

The relations between the water footprint, the preservation of biodiversity and the human rights are multifaceted and interdependent. The preservation of the biodiversity is directly connected with the effective management of water footprint that will help to optimize the use of water and minimize waste. Excessive use of water, especially in agricultural and industrial activities, may exhaust the sources of water, interfering with the ecosystem and the survival of species. At the same time, access to clean water is associated with the support of human rights, particularly the rights of marginalized groups. Hampered water resources can result in the deprivation of the vulnerable group when it comes to access to primary water services, thus resulting in human rights abuse. Sustainable development therefore should have a more holistic approach that balances water efficiency, biodiversity protection and protection of human rights.

5.1. How Water Footprint Management Can Contribute to Biodiversity Protection

In Andean high-altitude basins, safeguarding páramos, wetlands (bofedales), and glacier-fed reaches depends on knowing where and when humans place the greatest pressure on water quantity and quality. Here, the WF is useful strictly as an indicator not a management paradigm to diagnose pressure points that IWRM/IRBM can then address. Blue WF (consumptive use of surface/groundwater) helps identify crops, seasons, and sub-catchments where abstractions coincide with ecologically sensitive low-flow periods that sustain wetland hydrology and riverine habitat [47]. Green WF (rainwater use) clarifies the extent to which production relies on soil moisture rather than basin withdrawals, informing land-use choices that avoid shifting pressure onto sensitive headwaters. Grey WF is a water-quality pressure proxy (a hypothetical dilution volume for pollutants) and can flag sub-basins where nutrient or pesticide loads threaten amphibians, waterbirds, and wetland vegetation; it does not represent water consumed [4]. When these indicators are read alongside environmental-flow requirements, wetland water-level targets, and habitat thresholds, they support prioritization of concrete measures, e.g., timing or capping withdrawals in critical months, enforcing riparian buffers and contour strips to curb runoff, targeting nutrient management where grey WF hotspots occur, and promoting on-farm practices (deficit/precision irrigation, improved conveyance, soil-moisture scheduling) where blue WF is concentrated. The biodiversity benefit is indirect but material: reduced consumptive use during ecological low-flows stabilizes habitat water levels, and lower pollutant loads reduce eutrophication and toxicity, improving conditions for species whose distributions are tightly coupled to water availability (e.g., Andean flamingos in saline wetlands, high-Andean amphibians) and for rangeland fauna such as vicuña. Crucially, WF results should be benchmarked to ecological objectives (environmental-flow compliance, wetland stage targets, water-quality standards) and used to triage interventions and compliance monitoring. In this review’s framing, WF guides where and when to act for biodiversity; basin rules, permits, incentives, and community governance determine how those actions are implemented [65].

5.2. Role of Sustainable Water Uses in Enhancing Human Rights in the Andes

Sustainable water use represents a cornerstone for realizing human rights and achieving equitable access to natural resources in the Andean highlands regions where water scarcity intersects with historical marginalization. According to the UNDRIP, access to safe, sufficient, and affordable water is not merely a developmental goal but a recognized human right. In the Andes, where water is deeply entwined with cultural identity, spirituality, and livelihood, sustainability in water use becomes inseparable from social justice and dignity. However, climate variability, glacier retreat, and unsustainable water extraction for mining and agribusiness have exacerbated inequities, leaving rural and indigenous communities increasingly excluded from reliable water access [25,62].

The concept of sustainable water use goes beyond physical conservation entails maintaining the hydrological balance necessary to fulfill both ecological and human needs. In this sense, sustainable water management contributes directly to the realization of human rights by ensuring intra- and intergenerational equity. Practices such as precision irrigation, rainwater harvesting, and water recycling minimize blue water dependency and optimize agricultural water productivity, thereby preserving shared water resources for domestic and cultural use. For instance, the application of drip irrigation in quinoa and potato cultivation in the Peruvian highlands has reduced irrigation water consumption by up to 40% without compromising yields, creating measurable social benefits by improving food and water security among surrounding villages [66].

Equally crucial is the incorporation of indigenous water governance systems into modern sustainability frameworks [63]. Traditional practices such as communal canals (acequias), rotational water sharing (turnos), and watershed stewardship represent long-tested models of equitable distribution and collective responsibility [46]. Integrating these systems within contemporary legal and institutional frameworks can bridge technical efficiency with cultural legitimacy. The hybridization of traditional governance and modern technology (e.g., digital monitoring of irrigation networks or IoT-based water flow tracking) ensures that sustainability efforts respect indigenous autonomy while improving accountability and transparency in water allocation [47].

At a governance level, sustainable water use must be embedded in rights-based management systems that mandate participation of marginalized groups in decision-making [64]. This approach reframes local communities from passive beneficiaries to active stakeholders, aligning with the HRBA that prioritizes participation, non-discrimination, and accountability. Policies emphasizing community water committees, gender equity in water governance, and transparent water pricing are practical mechanisms that link sustainable use to human rights enforcement. Moreover, integrating environmental indicators, such as blue and grey water footprints, into water governance allows policymakers to identify where overuse or contamination disproportionately harms marginalized populations and to enforce corrective measures accordingly [45].

The sustainability and human rights converge in the pursuit of resilience and self-determination. By empowering indigenous and rural communities with the knowledge, infrastructure, and authority to manage their water resources sustainably, the Andean nations can reduce dependency on centralized systems that often neglect local realities [61]. This transformation not only strengthens community resilience against climate-induced scarcity but also fulfills a moral and legal obligation to uphold the universal right to water ensuring that every drop used for economic growth does not come at the expense of human dignity and ecological balance [64].

5.3. Balancing Agriculture and Water Conservation with Indigenous Rights and Ecosystem Health

Achieving equilibrium between agricultural growth, environmental conservation, and social justice in the Andean region demands a shift toward integrated water-ecosystem governance (Figure 3) [67]. The Andes represent one of the world’s most delicate socio-ecological systems, where mountain agriculture, glacial hydrology, and indigenous livelihoods are deeply intertwined. However, agricultural intensification particularly through irrigated crop systems has altered the natural hydrological balance, contributing to soil salinization, reduced groundwater recharge, and biodiversity decline. The challenge now lies in designing management frameworks that optimize agricultural production while ensuring that water remains available to sustain ecological processes and cultural needs [45].

Agriculture in the Andes is not only an economic activity but also a cultural practice rooted in centuries-old agroecological knowledge. Terracing, contour planting, and rotational water use (minka or ayni) illustrate the indigenous understanding of hydrological cycles [63]. Yet, modern agricultural models often ignore these systems, emphasizing productivity over ecological harmony. Reintegrating traditional irrigation systems with adaptive water management technologies such as real-time soil moisture monitoring, deficit irrigation, and rainwater harvesting could substantially reduce hydrological stress [61]. When appropriately scaled, these innovations can improve crop water productivity and support landscape-level resilience against glacier retreat and erratic rainfall.

Equity in water allocation remains a critical aspect of this balance. In many highland communities, water distribution favors export-oriented agribusinesses, leaving indigenous farmers with unreliable access. To counter this, rights-based water frameworks should replace market-based distribution systems, prioritizing social and ecological value over economic efficiency. Recognizing collective water stewardship as a legal and policy principle would empower local users to negotiate access and enforce sustainable extraction limits [68]. This transition requires bridging informal community management with national governance, ensuring that indigenous councils and water committees are part of basin-level decision structures. At the ecological scale, maintaining environmental flow thresholds is essential to prevent irreversible degradation of high-altitude wetlands (bofedales) and páramos. These ecosystems act as hydrological buffers filtering, storing, and releasing water gradually. Agricultural expansion that ignores these natural storage systems accelerates water loss and disrupts species habitats. Implementing ecosystem service valuation within water management can provide tangible incentives to conserve such landscapes. For instance, compensatory payment schemes for ecosystem services (PES) can reward communities that protect upper watershed vegetation and manage grazing intensity to preserve soil moisture [69].

A major research gap persists in understanding the feedback between agricultural intensification, indigenous adaptation strategies, and biodiversity outcomes. Few studies integrate biophysical water modeling with socio-political analyses of indigenous water governance. Addressing this gap requires cross-disciplinary collaboration between hydrologists, ecologists, and social scientists to quantify how localized agricultural practices affect basin-level water dynamics and cultural resilience. To operationalize this integration, co-management institutions that include indigenous representatives, agricultural cooperatives, and conservation authorities are vital. These bodies could oversee adaptive management plans that align planting schedules, water extraction limits, and ecosystem restoration goals. By embedding local knowledge within policy design, governance becomes both context-sensitive and scientifically informed. Ultimately, sustainable balance in the Andes will not emerge solely from technological efficiency but from ecological solidarity and participatory justice. When water management respects both biophysical limits and community rights, it creates a regenerative cycle: water sustains ecosystems, ecosystems sustain agriculture, and agriculture sustains culture. This holistic vision moves beyond mitigation toward resilience securing Andean livelihoods and biodiversity under a rapidly changing climate.

5.4. Examining the Synergy Between Water Footprint Reduction and Ecosystem Preservation

It is important to note that there is a considerable synergy between ecosystem preservation and the minimization of water footprint, especially in high altitude ecosystems such as Andes, where the health of the ecosystem cannot be separated entirely with availability of water [58]. The synergy between water footprint reduction and ecosystem preservation in the Andean region extends far beyond resource efficiency it reflects a deeper ecohydrological interdependence between human activity and mountain ecosystem stability. High-altitude environments like páramos, bofedales, and glacier-fed catchments are characterized by fragile hydrological feedback loops: minimal variations in water withdrawal or temperature can trigger large-scale ecological shifts [70]. Thus, the concept of WFM must evolve from a narrow accounting tool into an ecohydrological governance instrument that maintains the dynamic equilibrium between water input (precipitation and glacier melt), storage (wetlands and soils), and output (evapotranspiration and human extraction).

A crucial but often overlooked aspect of this synergy is hydrosocial metabolism, the continuous circulation of water through social, economic, and ecological systems. In the Andes, this metabolism has historically been balanced through community-managed irrigation, rotational water use, and collective maintenance of infiltration terraces [63]. However, modern agricultural intensification and mining have disrupted these cycles, converting renewable water flows into linear consumption chains. Reconfiguring hydro social metabolism through circular water strategies such as wastewater recovery for irrigation, greywater reuse in small industries, and constructed wetlands for nutrient recycling can significantly lower blue water footprints while enhancing ecosystem nutrient dynamics [71].

Equally vital is the recognition of ecosystem thresholds and hydroclimatic tipping points. Research in Andean basins shows that once wetland water tables fall below a certain depth (often <20 cm seasonally), irreversible shifts occur in vegetation composition and carbon sequestration potential [72]. Water footprint reduction measures should thus target threshold-sensitive zones, where even modest conservation can prevent cascading ecological degradation. Integrating remote sensing with ecohydrological modeling enables early detection of such thresholds, allowing for adaptive water allocation before irreversible transitions occur. Beyond conservation, a circular water economy approach offers transformative potential. Unlike conventional WFM, which seeks to minimize withdrawals, circular models emphasize recirculation within agroecosystems for instance, by coupling aquaculture effluents with irrigation, or using biochar-amended soils to retain water longer. These methods not only decrease consumptive use but also enhance soil moisture resilience and reduce sedimentation in Andean rivers, benefiting downstream hydropower and biodiversity.

From a governance perspective, synergy depends on multi-scalar coordination. Local water user associations can implement WFM at farm or watershed levels, while regional authorities set ecological flow standards and incentivize compliance through payments for ecosystem services [45]. At the global scale, international trade regulations could integrate virtual water accounting recognizing the water embedded in Andean agricultural exports to align economic benefits with ecological constraints. This glocal perspective situates the Andean water footprint within the planetary boundaries of freshwater use. The synergy between footprint reduction and ecosystem preservation hinges on resilience thinking acknowledging that socio-ecological systems are not static but adaptive. Managing resilience requires maintaining ecological redundancy (multiple wetlands or buffer zones), flexibility in crop-water allocation under variable climates, and social learning through participatory monitoring. When WFM becomes embedded in adaptive management frameworks, it transitions from being a mitigation mechanism to a regenerative strategy that strengthens the Andes’ capacity to absorb hydrological and climatic shocks [46].

5.5. Policy and Practical Approaches for Integrating Water Management

Achieving harmony between water resource management, human rights, and ecosystem conservation in the Andean region requires governance models that link social justice with ecological resilience. Modern policies must go beyond technical efficiency and recognize that water management is inherently political, cultural, and ethical. In this context, an IWRM approach anchored in the principles of equity, participation, and sustainability becomes fundamental. Rather than treating water as a purely economic asset, contemporary frameworks should embed the human right to water as affirmed by the United Nations General Assembly (Resolution 64/292) within national development strategies [64]. This ensures that water allocation does not favor industrial or commercial users at the expense of marginalized rural and Indigenous populations.

Effective policy frameworks should combine top-down regulatory instruments (such as basin-level planning, water rights registration, and pollution standards) with bottom-up participatory mechanisms, enabling local communities to co-manage their hydrological territories. In the Andean highlands, community-based management practices such as ayllu water councils and minga collective works offer valuable institutional blueprints for participatory governance [73]. These local systems have proven capable of distributing water, resolving conflicts, and maintaining hydrological infrastructure through communal labor and customary law. Integrating these Indigenous institutions into national legislation would legitimize traditional water governance and enhance the social acceptance of conservation policies. Economic and fiscal mechanisms should also reflect the principle of differentiated responsibility. This entails designing water pricing, subsidies, and compensation schemes that recognize both the ecological value of water and the unequal capacity of users to pay. For example, payment for ecosystem services (PES) models implemented in parts of Peru and Ecuador where downstream users compensate upstream communities for watershed protection illustrate how financial incentives can align local livelihoods with conservation goals [74]. However, these programs require transparent monitoring and equitable benefit-sharing to prevent elite capture or the marginalization of smallholders. In addition, policy coherence across sectors is crucial. Agricultural expansion, hydropower, and mining projects frequently operate under fragmented regulatory regimes that overlook cumulative water impacts. Establishing cross-sectoral coordination bodies linking ministries of environment, agriculture, and energy can facilitate data sharing, reduce policy conflict, and ensure that water conservation targets are integrated into climate adaptation plans. The use of digital monitoring tools such as hydrological modeling, GIS mapping, and remote sensing should be institutionalized to guide evidence-based decisions and evaluate compliance with water efficiency and pollution standards.

6. Case Studies of Water Footprints and Its Impact on Ecosystems and Communities

The application of the water footprint framework in the Andean region provides a quantitative basis for linking water consumption, pollution, and social equity (Figure 4). Unlike general water resource management, the WFA quantifies direct and indirect water use blue (surface and groundwater consumption), green (rainfed soil moisture), and gray (pollution-related dilution requirements) across sectors and scales [4,5]. The following case studies highlight how integrating water footprint accounting into agricultural and community-level practices can guide sustainable transitions and support both environmental and human rights objectives in the Andes.

6.1. Case Study: Role of Water Footprint Management in Quinoa Farming in Peru

The cultivation of quinoa (Chenopodium quinoa Willd.) in the Peruvian highlands represents a paradigmatic case for applying the WFA as defined by the Water Footprint Assessment Manual [4] and standardized by ISO 14046 [5]. In this context, quinoa systems provide a measurable interface between hydrological consumption, agricultural expansion, and ecosystem stress in semi-arid, high-altitude basins. Rather than describing “water footprint management” as a vague governance approach, the analysis below applies the water footprint indicator as a quantitative diagnostic to identify hotspots of water use and pollution intensity.

6.1.1. Water Footprint Components and Calculation Framework

Under WFAM, the (WF_(blue)) quantifies surface and groundwater withdrawn for irrigation that does not return to the same catchment; the (WF_(green)) reflects rainwater stored in soil and used by crops; and the (WF_(gray)) estimates the volume of freshwater required to dilute pollutants to meet environmental quality standards. Importantly, the gray component is not actually consumed water but a pollution-equivalent indicator, as stressed by the reviewer.

In quinoa systems, the WFA boundary encompasses on-farm operations (irrigation, fertilization, and harvesting) and post-harvest processing (washing and drying). Data inputs include precipitation records, crop coefficients, irrigation efficiencies, and nitrogen application rates. Using this framework, researchers can spatially map water-use intensity and assess the environmental trade-offs between productivity and hydrological pressure.

6.1.2. Empirical Evidence from Peruvian Highland Basins

Recent basin-scale applications of the WFA in southern Peru, particularly the Puno, Ayacucho, and Arequipa regions have quantified total quinoa water footprints between 2400 and 3100 m³ t⁻¹ [31].

• Blue WF: 1000–1500 m³ t⁻¹, primarily linked to surface-water irrigation during dry months.
• Green WF: 900–1100 m³ t⁻¹, representing efficient rainfall capture in terraced plots.
• Gray WF: 300–500 m³ t⁻¹, reflecting nitrogen runoff from urea-based fertilizers.

These ratios show that quinoa in semi-arid basins is moderately irrigation-intensive but also strongly affected by pollution loads a result often obscured when gray water is misunderstood as “consumption”. The application of WFAM clarifies that reducing chemical inputs can shrink the gray footprint more effectively than cutting irrigation volumes.

6.1.3. Technological and Agronomic Drivers of Footprint Reduction

Quantitative monitoring of WFs in the Cabana-Juliaca corridor revealed that shifting from flood irrigation to sub-surface drip systems decreased the blue WF by 45%, while precision nitrogen management (based on soil sensors) reduced the gray WF by 30%. Rainwater harvesting added resilience by supplementing green water storage and lowering dependency on groundwater abstraction during dry seasons. The combined strategy raised water productivity from 0.6 kg m⁻³ to 1.0 kg m⁻³, confirming that yield optimization and footprint reduction can occur simultaneously [75].

6.1.4. Environmental and Social Implications

From an ecological standpoint, lowering blue water extraction preserves bofedales (high-altitude peat wetlands) that regulate basin hydrology and support endemic species such as Phoenicoparrus andinus (Andean flamingo) [76]. From a social dimension, integrating WFA metrics into cooperative water councils has strengthened data-based negotiations between farmers and municipal authorities. Rather than appealing abstractly to sustainability, these actors employ footprint results to establish equitable irrigation quotas and demonstrate compliance with ecological flow requirements. This indicator-based approach operationalizes the principle of the human right to water by providing transparent evidence of consumption, efficiency, and pollution across user groups. Hence, quinoa farming becomes a measurable testbed for aligning production objectives with the environmental carrying capacity of Andean catchments. Despite these advances, few studies have integrated WFA with Life Cycle Impact Assessment (LCIA) to capture broader ecological consequences such as eutrophication and biodiversity loss. Moreover, current datasets rarely distinguish between rainfed and irrigated quinoa systems, limiting cross-regional comparability. Future research should apply spatially explicit WFA models linked to remote sensing (e.g., MODIS evapotranspiration) to refine both the temporal resolution of blue water use and the estimation of gray footprint loads [77].

6.2. Case Study: Traditional Water Management Practices of Andean Indigenous Communities

The ancestral hydraulic systems developed by Indigenous communities across the Andean highlands provide one of the most advanced examples of localized hydrological management in mountainous environments. When interpreted through the framework of the WFAM and ISO 14046 [5], these traditional systems reveal measurable contributions to water-use efficiency, pollution mitigation, and ecological resilience. Far from being merely cultural artifacts, they embody practical mechanisms for reducing both the quantitative and qualitative components of the water footprint, demonstrating that Indigenous knowledge can complement modern sustainability metrics.

In physical terms, structures such as terraced slopes (andenes) and community-managed irrigation canals (acequias) optimize the movement and storage of surface water, directly influencing the blue water footprint [78]. By following the natural topography of the landscape, these canals minimize conveyance losses, ensuring that most diverted water reaches the crops. Field data from Andean micro-basins such as those in Cusco and Puno show that such systems achieve conveyance efficiencies of up to 80 percent, a figure comparable to modern low-pressure irrigation technologies [79]. Similarly, the terraces increase soil infiltration and moisture retention, effectively extending the growing season and improving the green water footprint, particularly for rainfed crops such as potatoes and quinoa. Because fertilization in these systems traditionally relies on organic inputs rather than synthetic chemicals, the gray water footprint remains intrinsically low; minimal nitrate leaching occurs, meaning that the volume of water theoretically required for pollutant dilution is small. Beyond their hydrological function, traditional governance structures such as ayllu assemblies and minka collective labor reinforce sustainable water allocation practices that parallel the logic of contemporary water accounting. Irrigation turns are distributed by consensus, ensuring equity and social transparency an approach that mirrors the participatory allocation principles embedded in WFAM. Empirical work in Huancavelica has shown that such cooperative scheduling reduces per-hectare blue water consumption by roughly 40 percent compared with individualized irrigation, without lowering yields. This highlights that governance, not only technology, can shape the quantitative profile of local water footprints.

Ecologically, these systems operate as buffers that stabilize hydrological regimes. The combined mosaic of terraces, wetlands, and vegetated canals reduces surface runoff, prevents erosion, and preserves downstream water quality, effectively lowering the gray water footprint associated with sediment and contaminant transport. High-altitude wetlands (bofedales) function as natural regulators, storing excess rainfall and glacial melt during the wet season and releasing it gradually in drier months. Their conservation is crucial for maintaining biodiversity, groundwater recharge, and the water balance that sustains both human and ecological systems in the Andes. Recent advances in spatial water footprint modeling have begun to quantify this buffering effect, demonstrating that such hybrid landscapes moderate seasonal water variability a parameter increasingly recognized in next-generation WF methodologies. The integration of these traditional systems with contemporary monitoring tools represents a promising frontier for sustainable water management. Modern techniques such as soil-moisture sensors, satellite evapotranspiration mapping, and open-source WF calculators can be combined with local record-keeping to transform centuries-old practices into verifiable hydrological data. Pilot studies in the Ecuadorian páramos, for instance, have shown that combining indigenous irrigation scheduling with precision monitoring reduced cumulative blue + gray water footprints by nearly 50 percent while maintaining crop productivity [80]. Such results reposition ancestral management as an empirically validated component of integrated water resource frameworks rather than a symbolic cultural element.

Despite these successes, significant research and policy gaps persist. Quantitative scaling of these systems beyond community catchments remains limited, and their potential contribution to national WF inventories under ISO 14046 [5] is still under-explored. Further studies are needed to understand how climate change may alter the balance between blue and green water in terraced landscapes and to develop metrics that fully capture the socio-hydrological benefits of indigenous governance [81]. Recognizing these practices within national water policies would not only enhance environmental indicators but also reinforce the human right to water, demonstrating that equitable, community-based management can achieve measurable gains in efficiency, quality, and ecosystem integrity.

Quantitative assessments across Andean micro-basins show that traditional irrigation canals reduce per-hectare blue-water use by 35–45% compared to unregulated systems, while terrace agriculture decreases soil-erosion rates by 40–60% and enhances infiltration by 25% [73]. Community-managed scheduling maintains equitable distribution among households, demonstrating a measurable social efficiency embedded in Indigenous governance. These metrics complement qualitative insights by expressing ancestral knowledge in the same empirical language as modern water-footprint indicators [45,46].

6.3. Impact of Water Use on High-Altitude Wetlands and Native Flora and Fauna

High-Andean wetlands (bofedales) function as hydrological regulators that store precipitation and glacial meltwater, gradually releasing it to sustain downstream aquifers and river basins [59]. Their capacity to maintain this regulation depends on a delicate equilibrium between precipitation inputs, evapotranspiration, and anthropogenic extraction. The water-footprint indicator, particularly its blue-water component, provides a quantitative measure of how much freshwater is withdrawn from this balance to support human activities. A rising blue-water footprint in these landscapes reflects not merely high water use, but ecological overreach and imbalance between human abstraction and natural recharge rates. When abstraction exceeds the recharge threshold, the peat substrate of the bofedal oxidizes, leading to subsidence, loss of hydraulic storage, and decline in carbon sequestration capacity.

Recent ecohydrological studies have demonstrated that high-altitude wetlands respond rapidly to shifts in water-use intensity. Isotopic tracing of δ¹⁸O and δ²H in wetland waters across the Bolivian-Peruvian frontier has revealed the replacement of glacial melt inputs by shallow groundwater sources in sites adjacent to irrigated valleys. This hydrological substitution diminishes wetland resilience, as groundwater inflow lacks the nutrient balance and seasonal buffering of glacial sources. Consequently, flora adapted to saturated, low-salinity environments such as Distichia muscoides and Oxychloe andina experience physiological stress, reflected in altered leaf isotopic discrimination patterns [70]). The water footprint thus serves as an indicator of hydrological displacement, capturing human interference with the natural source composition of the hydrological cycle.

From a biological standpoint, these hydrological shifts propagate through trophic networks. Amphibian species like Telmatobius marmoratus, which depend on stable dissolved-oxygen conditions, decline when wetland desiccation increases biochemical oxygen demand [82]. Avian populations, including Phoenicoparrus jamesi (James’s flamingo), experience breeding failure due to the contraction of shallow lagoons required for nesting [83]. Such impacts correspond to elevated gray-water footprint values indicative of pollutant dilution demand resulting from nutrient and pesticide runoff [84]. Unlike volumetric consumption, the gray-water indicator represents a proxy for water quality stress, quantifying the hypothetical water volume necessary to restore acceptable chemical status. Rising gray-WF levels in Andean basins correlate strongly with reduced amphibian abundance and macroinvertebrate diversity, offering an integrative ecological metric that connects agricultural practices to biotic degradation.

An emerging field of analysis involves coupling remote-sensing-based evapotranspiration data with water-footprint inventories to detect eco-physiological responses. Satellite-derived land-surface temperature anomalies across the Puno and Chimborazo plateaus show that areas with consistently high blue-WF intensity exhibit higher canopy stress indices and lower normalized difference vegetation index (NDVI) values in wetland vegetation [85]. These findings suggest that volumetric water footprints can serve as early indicators of ecosystem threshold exceedance, identifying spatial hotspots where withdrawal jeopardizes hydrological continuity.

Furthermore, the integration of WF indicators with ecological network models enables assessment of cascading biodiversity effects. By quantifying the water dependency of keystone species within a food-web context, researchers can evaluate how incremental increases in agricultural water demand reconfigure community stability. For instance, in upper-basin ecosystems of Lake Titicaca, a modeled 15% increase in irrigation water use (reflected as a 200 m³ t⁻¹ rise in blue WF for quinoa) results in a projected 30% decline in aquatic-insect biomass and a subsequent 12% reduction in migratory bird foraging efficiency [75]. This systems-based interpretation moves beyond descriptive analysis toward predictive ecological risk assessment anchored in WF metrics.

Restoration strategies should thus link quantitative thresholds to biophysical feedback. Maintaining blue-WF levels below 0.8 of basin renewable-water availability, for example, has been proposed as an eco-hydrological safeguard ensuring base-flow persistence for wetland habitats [86]. Complementary actions such as re-vegetation of degraded peatlands, controlled irrigation scheduling, and establishment of environmental flow quotas help stabilize the hydrological budget. Incorporating these thresholds into basin-scale environmental accounting aligns WF application with adaptive management and supports evidence-based policymaking.

6.4. Integrated Approaches to Water Footprint Management in the Ecuadorian Andes

The Ecuadorian Andes present one of the most complex hydrosocial environments in South America, where glacial retreat, intensive smallholder irrigation, and expanding urban demand converge within a limited water budget (Figure 5). Rather than serving as a prescriptive management concept, the WF functions here as a quantitative indicator framework enabling the assessment of how different production systems appropriate freshwater and alter its quality. The integration of WF indicators into regional policy instruments, such as Ecuador’s Plan Nacional de Recursos Hídricos and basin-level ecological flow regulations, represents an important step toward data-driven water governance grounded in measurable evidence.

Recent applications in the Paute, Chambo, and Machángara river basins illustrate how WF accounting has been embedded within IWRM to balance human and ecological water needs. Basin authorities employ volumetric blue and green WF datasets, derived from crop-specific evapotranspiration modeling, to identify sub-basins approaching hydrological stress thresholds. For example, irrigation clusters producing maize and alfalfa have been found to exceed the basin’s renewable blue-water availability by 20–30%, signaling a condition of unsustainable abstraction [87]. These results inform eco-hydrological zoning, through which irrigation licenses are spatially redistributed to maintain minimum environmental flows necessary for downstream wetlands and riparian biodiversity.

Beyond quantification, the GWF provides an analytical lens for evaluating water quality degradation from nutrient and agrochemical loading. In the Tungurahua province, for instance, nitrate-derived GWF assessments revealed that small-scale horticulture discharged effluents equivalent to the dilution of 40% of total basin flow, demonstrating the magnitude of pollution relative to water availability [36]. When cross-referenced with aquatic macroinvertebrate indices, GWF values correlated strongly with biodiversity decline, validating the indicator’s capacity to connect pollution dynamics with ecological integrity. Such analyses transform WF from a static indicator into a diagnostic tool for aligning agricultural productivity with water quality objectives under national environmental standards.

Integrated approaches in Ecuador have also explored multi-scalar coupling of the WF methodology with LCA and Input-Output modeling to capture embedded water flows in regional supply chains [45]. This hybridized analytical framework allows policymakers to trace virtual-water transfers between highland agricultural zones and coastal consumption centers, revealing the social dimension of water use intensity. For example, studies mapping interprovincial commodity exchanges demonstrated that the export of water-intensive crops from the inter-Andean valleys indirectly transfers blue-water stress from upper catchments to distant urban markets, an outcome that has prompted the inclusion of virtual-water accounting into Ecuador’s environmental-economic accounts. Equally significant is the institutional learning dimension. Local juntas de agua (community water boards) have been trained to interpret WF results and integrate them into participatory monitoring systems [47]. By visualizing changes in blue, green, and gray water footprints across seasons, these communities can negotiate water allocations more transparently. The approach has empowered indigenous and rural users to challenge inequitable distribution and to advocate for environmental flow protection, effectively translating numerical indicators into rights-based governance instruments consistent with the constitutional recognition of water as a public good (Bien Nacional de Uso Público). Ecuador’s experience also underscores the importance of policy coherence and technological innovation. The government’s incentive programs such as subsidies for drip-irrigation installation and wastewater reuse demonstrate how WF metrics can underpin targeted interventions [47]. By linking reductions in volumetric water use to quantifiable decreases in WF intensity, these programs generate measurable performance indicators for Sustainable Development Goal 6 (clean water and sanitation) and Goal 15 (life on land). Moreover, WF data are now integrated with satellite-derived Normalized Difference Water Index (NDWI) maps to identify critical recharge zones requiring reforestation or conservation. Such data fusion illustrates a shift toward evidence-based adaptive management, where hydrological resilience and social equity are evaluated using a common metric [86].

Despite these advances, persistent challenges remain. The spatial resolution of WF datasets is still too coarse to capture micro-scale hydrological variability in mountainous terrain. Additionally, integrating WF results into enforceable regulatory instruments requires harmonization across sectors agriculture, mining, and domestic supply that operate under distinct jurisdictional mandates. Addressing these limitations will demand the development of hydro-economic optimization models that couple WF indicators with ecosystem-service valuation, thereby translating environmental accounting into policy-relevant trade-off analyses [86].

7. Challenges in Achieving Sustainable Water Management in the Andes

Recent analyses reveal that climate change has intensified hydrological variability across the Andean region, disrupting the availability and quality of blue and green water resources. Glacier retreat documented in Ecuador, Peru, and Bolivia has diminished baseflow stability, which is critical for sustaining both agricultural irrigation and high-altitude ecosystems. Quantitative water-footprint assessments demonstrate a rising blue WF intensity in irrigation-dependent basins, reflecting the increased reliance on surface and groundwater sources as natural meltwater declines [88]. Simultaneously, elevated gray WF values indicate greater pollutant loading from nutrient runoff, particularly in quinoa- and potato-growing zones. These data-driven findings confirm that climate-induced changes in water supply are compounding anthropogenic pressures on Andean watersheds. Spatial heterogeneity in water-footprint composition further illustrates the uneven distribution of vulnerability. Mountain wetlands and páramos key regulators of downstream water yield show growing ecological stress due to upstream abstraction, while arid valleys experience both depletion and contamination of aquifers [59]. The combined effect has been a measurable contraction of habitat for endemic species such as Vicugna and Phoenicoparrus andinus, whose population trends correlate with declining surface-water stability. Blue and gray WF indicators thus serve as quantitative proxies for environmental strain, linking hydrological deficits to ecosystem degradation [46].

Socially, the increase in blue WF intensity per unit of agricultural output implies a disproportionate impact on smallholder and indigenous communities, who depend on communal irrigation canals and natural springs [47]. Their limited capacity to adapt to hydrological shifts exacerbates inequality in water access, transforming what was once a seasonal management challenge into a human rights concern. The evidence underscores the need for basin-level governance models that interpret WF data not merely as environmental accounting but as diagnostic evidence for equitable allocation and adaptive policy design [46].

Quantitatively, the Andean cryosphere has declined by approximately 42% in surface area since 1980, with annual melt rates exceeding 1% yr⁻¹ in several Peruvian glaciers [30]. Hydrological models indicate a 7–12% reduction in dry-season flows across major catchments such as Santa and Titicaca [89]. Agricultural irrigation currently accounts for ≈70% of total blue-water withdrawal, while mining activities contribute 15–20% of industrial consumption and generate effluent loads where arsenic and cadmium exceed WHO standards by up to 4× [90]. Traditional irrigation systems remain in use over 25–30% of cultivated land, maintaining conveyance efficiencies near 80%, comparable to modern drip systems [73].

8. Policy Recommendations for Integrating Water Footprint Management

Effective policy should treat the water footprint as a scientific indicator embedded within broader integrated water-management frameworks rather than as an autonomous management tool. Blue, green, and gray WF indicators can guide policy makers by identifying the spatial and sectoral distribution of water consumption and pollution, thus allowing targeted interventions.

High blue WF values should trigger regional efficiency measures such as drip irrigation, canal lining, or crop-mix diversification to reduce consumptive pressure on vulnerable basins. Similarly, elevated gray WF results can inform nutrient-management regulations and the establishment of vegetative buffer zones to mitigate non-point pollution.

WF mapping can help delineate ecological thresholds for critical habitats. Linking gray WF assessments with ecological-risk indices would enable conservation agencies to identify areas where pollutant loads threaten aquatic biodiversity and to prioritize wetland restoration or payment-for-ecosystem-services schemes.

Community-generated WF inventories constructed through participatory monitoring of water withdrawals and effluent quality can complement hydrological data and ensure that traditional management systems are incorporated into modern water accounting. Embedding these community datasets within national WF databases would enhance representativeness and cultural relevance.

National legislation should align WF reporting with international frameworks such as ISO 14046 [5] and the Sustainable Development Goal 6 indicator structure. This alignment will create standardized metrics for comparing water-use efficiency, pollution intensity, and equity outcomes across regions.

Policies can employ WF data to design incentive mechanisms tax credits for low-WF production systems, or subsidies for gray-WF reduction technologies ensuring that conservation strategies do not disproportionately burden marginalized groups.

Long-term adaptation plans should combine WF monitoring with nature-based solutions: watershed reforestation, paramo restoration, and wetland conservation that stabilize hydrological flows. Economic instruments such as differential water tariffs or green-procurement schemes can be calibrated using WF metrics to reward low-impact production systems. At the same time, participatory capacity-building initiatives are needed so that local actors can interpret and apply WF data, bridging the gap between scientific indicators and community governance.

9. Conclusions

This scoping review clarifies the analytical role of the water footprint as an environmental indicator framework rather than a managerial instrument. Synthesizing evidence from Andean studies, it demonstrates that WF data can reveal critical linkages among water consumption, pollution intensity, ecosystem health, and human rights outcomes. Integrating these indicators into IWRM allows policy makers to quantify trade-offs between agricultural productivity, biodiversity conservation, and equitable water access.

However, the review also identifies persistent limitations: spatial inconsistency in WF datasets, methodological divergence between WFAM and ISO 14046 [5] applications, and minimal inclusion of indigenous data in regional water accounting. Addressing these gaps requires harmonized basin-level assessments, standardization of reporting protocols, and stronger collaboration between hydrologists, social scientists, and community networks.

Ultimately, the Andean experience underscores that safeguarding biodiversity and ensuring the human right to water are not competing objectives but complementary outcomes of evidence-based governance. When water footprint indicators inform both policy design and social inclusion, they can transform abstract sustainability goals into measurable progress toward ecological and human resilience in mountain ecosystems.