Agriculture in the Andes is highly dependent on irrigation, yet water conveyance and application methods remain predominantly premodern. Unlined earth canals and gravity-fed flood irrigation dominate the landscape, often resulting in conveyance losses of 20-40% and on-farm application efficiencies of 50-60% [32]. These inefficiencies impose significant pressure on water resources, especially during dry seasons, particularly when demand peaks. Crop choices further compound the challenge: water-intensive staples such as potatoes and maize require sustained irrigation, thereby amplifying the stress created by inefficient conveyance systems [33]. By contrast, native crops like quinoa rely more on green water and demonstrate greater resilience to scarcity, suggesting opportunities to mitigate water pressure through crop diversification [29]. Linking these dynamics to climate change presents an even more urgent scenario: as glacier retreat diminishes dry-season water availability, the persistence of inefficient irrigation and water-intensive cropping systems further amplifies vulnerability. In this context, water footprint accounting (WFA), which disaggregates green, blue, and grey water components, becomes essential for identifying and prioritising interventions that balance agricultural productivity with water conservation. Comparative studies outside the Andes have demonstrated that lining canals and adopting pressurised or micro-irrigation can raise efficiency to over 90%, highlighting the considerable potential for reducing the blue water footprint in Andean farming systems.

Quantitative assessments of crop water footprints further highlight the scale of pressure on Andean water resources. Global and regional studies indicate that potatoes require approximately 287 litres of water per kilogram of production, while maize demands nearly 1,222 L kg⁻¹ [33]. By comparison, quinoa averages 1,200-1,500 L kg⁻¹, yet much of this demand is satisfied through green water, making it more resilient under scarcity conditions. These figures illustrate how crop choice directly influences the magnitude of water extraction from rivers and aquifers. Crop selection further shapes the water footprint: potatoes and maize typically require significant irrigation, while quinoa and other native crops exhibit greater resilience to water scarcity through their reliance on green water. Applying WFA, which disaggregates green, blue, and grey components, enables farmers and policymakers to identify which cropping systems impose the heaviest pressure on scarce water resources [34].

Caution must be taken regarding the variability and uncertainty in crop water footprint estimates. The water footprint is highly dependent on local climatic conditions (temperature, precipitation, and evapotranspiration), soil properties (texture, depth, and water-holding capacity), irrigation technology (surface, sprinkler, or drip), and management practices (planting density and fertilisation). In the Andes, the sharp altitudinal gradients and big seasonal differences further increase the spatial heterogeneity of the green, blue and grey components of water. Also, differences in methods across studies, including the selection of evapotranspiration models, the spatial resolution of remote sensing data, and assumptions about effective precipitation, create uncertainty in footprint estimates [35]. The values of the water footprint must therefore be viewed as expected ranges, rather than exact values and as such, site-specific measurements and sensitivity analyses are necessary when applying WFM to Andean agricultural systems.

Beyond agriculture, rural Andean households rely on multi-use community-managed systems that combine domestic supply, livestock watering, and small-scale irrigation. These systems, often administered by local committees, are especially vulnerable during dry seasons when water is contested between urban centres, commercial farms, and Indigenous communities. In places such as La Paz - El Alto, glacier retreat has reduced dry-season water reliability, intensifying competition [36]. Applying WFA at the community scale provides a mechanism to distinguish domestic blue-water needs from agricultural consumption, thereby clarifying conservation and equitable distribution priorities. Traditional recharge infrastructures, particularly the ‘amunas’ in Peru, exemplify nature-based solutions that directly enhance local water security. By diverting wet-season flows into hillslopes, ‘amunas’ delay runoff and augment dry-season baseflow, with studies documenting median delays of 45 days and average dry-season gains of around 7.5% in Lima’s source waters [37]. Recent rehabilitation programs have extended these systems, supporting urban and rural resilience alike. However, despite promising hydrological outcomes, their broader impacts on water quality, equity, and long-term governance remain poorly quantified. Reported baseflow increases of approximately 7.5% associated with ‘amunas’ are derived primarily from case studies in the central Peruvian Andes, particularly in catchments supplying the Lima metropolitan region [38]. They are highly dependent on local hydrogeology, soil permeability, slope and precipitation regimes, and cannot be directly extrapolated to drier southern Andes or highly fractured volcanic environments. Besides this, hydrological modelling of ‘amunas’ is subject to uncertainties arising from a lack of long-term monitoring data, assumptions on the direction of movement of underground water, and interannual variability. These values must therefore be understood as indicative rather than universal, with emphasis on the need for a site-specific evaluation before replication.

In the Andes, Indigenous water governance is highly diverse and local rather than universal. For example, Quechua communities in the central and southern regions of the Peruvian Andes tend to coordinate irrigation through communal ‘acequias’ organised by rotating assemblies, known as ‘faenas’ [39]. In contrast, Aymara systems of the Peruvian Altiplano rely on ‘ayllu’ leadership and collective regulations related to pastoralism and wetland administration. In the páramo areas of Ecuador, water governance is often a synthesis of community councils and water-user associations, both legally established and representing various historical and institutional pathways. By recognising this diversity, Indigenous water governance is not treated as a single model, underscoring the need to integrate WFM into the context.

Although most of the old Andean water systems are adaptive and resilient, not all are sustainable under the current climate pressures. Occurrence of amoebas, ‘bofedales’ management and rotational grazing practices tend to increase infiltration and ecosystem stability, but other practices like ungulates surface diversion or increased flood irrigation are more likely to increase water stress in response to reduced glacier melting and changed rainfall regimes [40]. Therefore, certain conventional systems need to be adjusted by introducing refined allocation regulations, hydrological monitoring, or additional efficiency measures to survive in the face of mounting climate change. To implement WFM effectively and in a culturally appropriate manner, certain practices must be identified as resilient and adaptation-dependent.

Accurate water footprint measurement in the Andes is complicated by steep topography, rapidly changing glacier dynamics, and sparse hydrological records. Traditional gauging networks are insufficient for capturing the high temporal and spatial variability of water flows, prompting interest in remote sensing and IoT-based monitoring of evapotranspiration, soil moisture, and streamflow. Integrating these technologies into WFA can provide basin-scale visibility of consumptive use while tracking green, blue, and grey water footprints across agricultural and community sectors [41]. Recent applications of remote sensing and hydrological modelling have advanced the estimation of crop- and basin-scale water footprints. For instance, Feng et al. [42] derived regional maize water footprints using MOD16 evapotranspiration (ET) products in combination with the data from Global Land Data Assimilation System (GLDAS). Similarly, Sun et al. [43] produced high-resolution maps of green and blue agricultural water footprints at the pixel level through remote-sensing ET datasets. The Food and Agriculture Organisation’s WaPOR database has supported multiple case studies that apply satellite-based ET to water auditing from basin to irrigation scheme scales [44]. The WA+ framework has been used for basin-wide water accounting with remote-sensing ET in regions such as the Indus. In the western United States, the OpenET platform now provides validated field-scale ET estimates that enable water managers to perform depletion accounting.

Likewise, studies using the SWAT model, such as in the Ceyhan Basin, have demonstrated the integration of hydrologic modelling to refine estimates of effective precipitation and partition green and blue water footprints [45]. Standardised indicators to link footprint reductions with biodiversity outcomes are absent, and wetlands monitoring remains fragmented across agencies. Without such integration, WFA risks remaining a technical exercise divorced from ecological realities, limiting its value for long-term adaptation strategies in the Andes. The WFM is typically assessed through three complementary components: green, blue, and grey water footprints. Grey-water footprint assessment is particularly relevant in mining-impacted Andean catchments, where water-quality degradation represents a major driver of ecological and social risk. In regions such as Cajamarca, Cerro de Pasco, and the Santa River basin, elevated concentrations of heavy metals, including arsenic, cadmium, and mercury, have been documented downstream of mining operations [46]. These pollutants substantially increase the grey-water footprint by requiring large volumes of freshwater to dilute contaminant loads to acceptable environmental standards. In such contexts, grey-water footprints often exceed blue-water footprints, underscoring that pollution, rather than abstraction alone, is a dominant constraint on water availability. Incorporating grey-water indicators into WFM, therefore, provides a critical lens for evaluating trade-offs between extractive activities, ecosystem health, and downstream water security in the Andes. The green water footprint represents the volume of rainwater consumed by crops and vegetation through evapotranspiration; the blue water footprint accounts for surface and groundwater withdrawn for irrigation, domestic use, and industry; and the grey water footprint measures the volume of freshwater required to assimilate pollutants, such as fertilisers or pesticides, to meet water quality standards [41]. These indicators, expressed in cubic metres per tonne of product (m³ t⁻¹) or litres per kilogram (L kg⁻¹), provide a standardised way to compare water-use efficiency across crops, households, and basins. In the Andean context, quantifying all three components is essential: green water dominates rainfed quinoa systems, blue water drives irrigation-dependent maize and potato production, and grey water reflects pollution loads from fertilisers, mining, and wastewater. Integrating these metrics allows WFM to move beyond generalised notions of scarcity and instead target specific levers for reducing pressure on ecosystems while safeguarding community needs [45].

Despite their analytical potential, remote sensing and Internet of Things (IoT) based monitoring systems face significant feasibility barriers in rural Andean contexts. High upfront costs for sensors, data loggers, and maintenance limit adoption among smallholder communities and local water-user associations. Technical capacity constraints, including limited training in data interpretation and system maintenance, further restrict effective use. Connectivity challenges are particularly acute in high-altitude regions, where unreliable electricity supply and weak mobile or internet coverage hinder real-time data transmission [47]. In addition, institutional fragmentation and short project cycles often result in pilot initiatives that lack long-term support and integration into local governance structures. Addressing these barriers requires low-cost monitoring technologies, capacity-building programs, offline-capable data platforms, and sustained institutional partnerships to ensure that digital WFM tools are both accessible and locally actionable.

The process of incorporating water footprint management into local water governance systems in the Andes has several major research gaps that must be addressed to achieve sustainable water use in the region. Among the key gaps is the poor understanding of the implications of water footprint management for local communities, particularly marginalised populations, such as Indigenous people and smallholder farmers. Although the latter is gradually being applied, water footprint management practices have yet to receive ample studies on their socio-economic impacts in such communities. Research is recommended to investigate the social and economic effects of conservation measures, focusing on the livelihoods of local communities and the convergence of these measures with traditional water rights. A study by Hailegnaw et al. [48] highlights the need to explore the domains of socio-economic influences in greater depth, particularly the interests of marginalised populations and the mutually beneficial relations between them and contemporary forms of governance. Also, Leroy et al. [49] emphasise the importance of accounting for local socio-political processes in implementing the strategy for managing the water footprint. Community engagement in WFM can be operationalised through concrete mechanisms rather than general participation. One promising avenue is citizen science, where farmers and households collect data on rainfall, soil moisture, or irrigation timing using low-cost sensors or mobile applications. Such data can feed into basin-level observatories, improving the resolution of hydrological monitoring while empowering communities with actionable knowledge.

Another approach is the creation of local water observatories, participatory platforms where community members, municipal officials, and researchers jointly review water footprint indicators and negotiate allocation priorities. These observatories can function as early-warning systems for scarcity and biodiversity risks, while also strengthening accountability in water governance. In addition, co-management agreements that formally integrate Indigenous water-sharing traditions (e.g., ‘amunas’ or communal canals) with modern WFM tools create institutional spaces where local knowledge informs basin planning [3]. Together, these mechanisms move participation beyond symbolic involvement toward structured roles that ensure communities actively shape data generation, decision-making, and policy implementation.

Traditional methods include irrigation canals and terracing in Andean regions, practices that have been sustained for centuries as integral components of community-based water governance. There has, however, been minimal research on the issues and successes of combining these practices with modern methods such as drip irrigation and micro-sprinklers. The study should examine the compatibility of existing systems, the problems encountered during integration, and what led to more sustainable water consumption. According to Ghorbanpour et al. [50], additional empirical studies are required to evaluate the possibilities of combining the traditional and new water management techniques. Similarly, Hoogesteger et al. [51] posit that the decentralised interaction methodology between these systems should be understood to achieve effective water conservation and social acceptability. Future research could also examine how hybrid systems, where ancestral techniques are supplemented by sensor-based irrigation scheduling, perform under conditions of seasonal water stress. As shown in Table 2, these traditional practices illustrate how Indigenous knowledge contributes to sustainable water governance and ecosystem protection in Andean agricultural systems. The other gaps that have not been fully exploited are equity in water footprint management, especially between big agribusiness and small farms. Increasing water consumption in industrial-scale agriculture may intensify preexisting water access shortages, particularly impacting the local population. Socio-economic differences in water access should be researched to identify ways to ensure that vulnerable groups are not disproportionately affected by water footprint management.

Uhlenbrook et al. [61] consider the fair distribution of water a critical form of sustainability and warn that massive agricultural activities should not distract from the interests of the local population. The authors note that participatory water management plays a significant role in empowering marginalised groups by including them in decision-making, a crucial step for attaining equality in water distribution [62]. However, little is known about how gender dynamics, migration, and intergenerational knowledge transfer influence equitable participation in water governance, representing a significant research gap. For community-based water governance models, more research is needed in this aspect as well. Although the community-based governance system has been introduced in some parts of the Andes, there is insufficient research on its contribution to the effectiveness of water footprint management. Evaluating how participatory decision-making, water-sharing agreements, and community-led initiatives can be integrated with modern water management practices is important. Bos and Brown [63] outline the potential of local governance to promote water conservation, yet more studies are required to elucidate which processes ensure its effectiveness. Decentralised management may foster water conservation, but it needs investigation to determine its capacity to support water footprint management.

The absence of detailed knowledge on these gaps has significant implications for both policy and practice in the Andes. Without evidence on the socio-economic impacts of WFM on smallholders and Indigenous groups, conservation policies risk reinforcing existing inequalities by favouring commercial agriculture over subsistence farming [3]. Similarly, the lack of studies on hybrid systems combining ancestral techniques with modern technologies hinders the design of context-appropriate irrigation programs, leading to low adoption rates or the erosion of traditional governance structures [64]. Weak monitoring frameworks and real-time indicators limit governments’ ability to anticipate water shortages, undermining adaptive planning under accelerating glacier retreat [65]. Finally, insufficient research on equity dimensions such as gender, migration, and generational knowledge transfer means that water governance reforms may overlook key drivers of participation and exclusion [62]. In practice, addressing these gaps is not only a matter of academic rigour but a prerequisite for crafting policies that are socially equitable, technologically viable, and ecologically sustainable in Andean communities. Given the Andean coastal connectivity, WFM integration must extend beyond local governance to basin-to-coast frameworks that align highland community systems with coastal water demand management.

The Andes is considered among the most biodiverse regions in the world, with an abundance unmatched by any other region, and many species and ecosystems that differ drastically with altitude and geography. The area has a variety of ecosystems, such as cloud forests, high-altitude wetlands, temperate rainforests, and parched deserts. Ecosystems do not just harbour unique plant and animal species; they are also ecologically critical for regulating hydrology and biodiversity across South America [69]. Biodiversity is especially high in cloud forests located in the lower and mid-altitude Andes. The forests are also marked by an abundance of mist and moisture, creating a distinct microclimate that supports numerous plant species, mosses, and epiphytes. These ecosystems support rare and emblematic species, including the Andean (spectacled) bear (Tremarctos ornatus) and the endangered mountain tapir, as well as a rich diversity of birds, amphibians, and reptiles [70]. For example, Sangay National Park in Ecuador, one of the most ecologically intact Andean reserves, harbours over 430 bird species, 107 mammals, 33 amphibians, and 14 reptiles, making it a critical biodiversity stronghold [71]. These wetlands provide a critical water source and play a pivotal role in regulating the hydrological cycle by storing and gradually releasing flows into rivers. They constitute essential habitat for endemic species such as the Andean flamingo, the vicuña, and various species of high-altitude plants that grow in nutrient-poor soils. Ecosystems also help regulate water quality, making them crucial to biodiversity and human water consumption. As illustrated in Figure 2, these ecosystems are closely linked to water availability, and disturbances to water resources pose a direct threat to the existence of these species and ecosystems [72].

Figure 2.

Functional linkages between water balance and biodiversity balance in Andean ecosystems

Water is a cornerstone of biodiversity in the Andes, where ecosystems depend on both the availability and quality of freshwater resources. Glaciers, rivers, lakes, and aquifers provide continuous inputs that sustain agriculture, wetlands, and habitats. Still, unlike in many temperate regions, water distribution here is highly seasonal and strongly influenced by glacier melt. Seasonal meltwater from glaciers and snowpacks regulates not only river discharge but also soil moisture, allowing high-altitude grasslands, shrublands, and mosses to persist in otherwise nutrient-poor soils. These vegetation systems form the foundation of Andean food webs. Such plants stabilise soils and supply forage to herbivores such as the vicuña (Vicugna vicugna). Beyond their ecological role, vicuñas also hold deep cultural and economic significance in Andean societies, valued since pre-Inca times for their exceptionally fine wool, which remains one of the most expensive natural fibres worldwide and contributes to rural livelihoods today.

Other emblematic species tied to water availability include the Andean (spectacled) bear (Tremarctos ornatus), Andean condor (Vultur gryphus), mountain tapir (Tapirus pinchaque), Andean flamingo (Phoenicoparrus andinus), and giant coot (Fulica gigantea). By consistently identifying both common and taxonomic names, biodiversity assessments in this region can better bridge ecological and conservation discourses. Water also underpins the functioning of soil microbial communities. Microorganisms in the Andes decompose organic matter, recycle nutrients, and maintain soil fertility. For example, nitrifying bacteria (Nitrosomonas spp.) regulate nitrogen availability, while arbuscular mycorrhizal fungi facilitate nutrient uptake by plants under water-limited conditions [73]. When water availability decreases, these microbial processes slow dramatically, cascading effects on vegetation productivity and carbon cycling. It highlights that water scarcity is not only a problem for visible flora and fauna, but also for the hidden microbial networks that sustain ecosystem health. In addition, water quality degradation has emerged as a key stressor. Agricultural runoff, untreated wastewater, and industrial effluents reduce oxygen levels, alter microbial assemblages, and impair aquatic biodiversity. Studies from Ecuador and Peru show that native fish populations decline sharply in streams exposed to fertiliser and pesticide contamination, disrupting food webs that extend to birds and mammals [74]. These stressors compound the impacts of glacier retreat, further threatening Andean biodiversity. Given the high dependence of ecosystems on freshwater, sustainable water management is essential. Traditional approaches such as irrigation canals and communal water-sharing systems have long helped buffer communities and ecosystems against scarcity. Recent studies emphasise that integrating these practices with modern hydrological tools, such as remote sensing and watershed modelling, can enhance monitoring of water availability and guide adaptive conservation policies [75]. This hybrid approach is urgently needed to balance agricultural use with biodiversity protection across the Andes.

Unsustainable water practices in the Andes are placing ecosystems under severe strain. Traditional surface irrigation, still dominant in many agricultural valleys, results in greater inefficiencies. More than half of diverted water is lost through conveyance before reaching the fields, creating shortages for downstream wetlands and aquatic habitats [76]. New hydrological surveys in Ecuador and northern Peru indicate that water losses in unlined canals range between 45-65%, with the greatest deficits recorded during the dry season when ecological demand is highest [77]. This situation not only reduces water availability but also intensifies competition between communities, agriculture, and biodiversity. Beyond quantity, water quality deterioration represents an equally critical threat. In Andean catchments with intensive potato and maize production, elevated nitrate and phosphate levels have been linked to algal blooms and oxygen depletion in high-altitude lakes, resulting in fish mortality and reduced aquatic invertebrate diversity.

Similarly, mining effluents containing heavy metals continue to contaminate rivers in Bolivia, Chile, and southern Peru, with cadmium and lead concentrations frequently exceeding international safety standards. These contaminants bioaccumulate through food webs, undermining amphibian survival and reducing reproductive success in aquatic birds. Climate variability further compounds these risks. Recent analyses show that the tropical Andes have experienced a 20% increase in extreme rainfall events over the last three decades, alongside prolonged seasonal droughts [78]. Such variability destabilises wetland hydrology and accelerates soil erosion on steep slopes, reducing the resilience of ecosystems to support plant and animal life. Unlike glacier retreat (already discussed in earlier sections), these shifts in rainfall regimes highlight a different dimension of climate pressure on biodiversity. At the species level, altered hydrology has caused population stress in endemic amphibians such as Telmatobius marmoratus, whose tadpoles depend on stable stream flows, and in aquatic birds like the Andean goose (Chloephaga melanoptera), which requires persistent wetlands for feeding and breeding [79]. These impacts illustrate the cascading nature of water-related stressors on trophic networks and community stability. The combined pressures of water mismanagement and climate change thus expose Andean ecosystems to unprecedented vulnerability. A major research gap remains in linking hydrological disturbance with biodiversity decline through long-term monitoring. While there is substantial hydrological modelling of glacier retreat, far fewer studies integrate socio-hydrological dynamics (irrigation governance, water rights) with biodiversity outcomes. Future work should prioritise interdisciplinary approaches that merge hydrology, ecology, and local governance to predict and mitigate biodiversity losses.

To enhance comparability across case studies, each example is presented using a standardised analytical structure comprising: (i) geographic location and hydrological setting; (ii) primary water-related problem or driver of change; (iii) relevant WFM governance, or policy intervention (where applicable); and (iv) documented ecological and social outcomes. This structure facilitates cross-case comparison and highlights how different combinations of climatic pressures, human activities, and governance responses shape water-related impacts across the Andes.

Water-related pressures on Andean ecosystems manifest in concrete regional case studies, providing insight into how unsustainable practices and environmental change interact with biodiversity decline. These examples highlight the ecological consequences of poor water management, agricultural intensification, and industrial activity. This review used case studies from 2000-2025 to examine links between water footprint management, biodiversity, and Indigenous rights in the Andes. Fifteen studies were selected for geographic relevance, documentation quality, and focus on water use and governance. A thematic analysis captured ecological settings, biodiversity impacts, and management strategies, enabling cross-country comparisons and identification of regional gaps.

One striking example comes from the Bolivian ‘altiplano’, where irrigation withdrawals from Lake Poopó caused the near-total collapse of the ecosystem in 2015. The lake, once covering more than 3,000 km², shrank to less than 10% of its historic size due to upstream diversion and mining effluents [80]. This development led to the decline of fish populations and the displacement of migratory bird species, including the Andean flamingo (Phoenicoparrus andinus) and the Andean avocet (Recurvirostra andina). The collapse of Lake Poopó reflects the interaction of both climatic variability and human water extraction rather than a single causal factor. Prolonged drought conditions and increased evapotranspiration associated with climate change reduced inflows and heightened the lake’s sensitivity to disturbance. However, these climatic stresses were compounded by extensive upstream water withdrawals for irrigation and mining, as well as channel modifications that diverted inflows away from the lake. Evidence indicates that while climate variability acted as a triggering stressor, sustained human extraction and governance failures were the dominant drivers that transformed episodic low-water conditions into a systemic collapse. This interaction underscores the importance of integrating climate risk with controls on consumptive and grey-water footprints in endorheic Andean basins.

In southern Peru’s high-altitude wetlands (bofedales), intensification of camelid grazing has been linked to vegetation loss, soil compaction, and reduced wetland hydrological capacity [81]. These alterations decrease wetlands’ resilience to seasonal drought and reduce habitat availability for endemic amphibians, particularly Telmatobius species, many of which are already threatened by chytrid fungus. Another case comes from the Cajamarca mining region of northern Peru, where open-pit gold extraction has altered water quality and hydrology. Elevated levels of arsenic and mercury have been recorded in rivers adjacent to mining zones, impacting aquatic macroinvertebrates and fish communities that form the base of the food web. The standardised case studies demonstrate that hydrological collapse and biodiversity loss in the Andes typically emerge from coupled climate and governance pressures, reinforcing the need for basin-scale WFM rather than sector-specific interventions. The key examples illustrating these governance approaches are presented in Table 3 and commented on.

The WFM provides a structured framework for linking water-use efficiency with biodiversity conservation in the Andes. Instead of repeating previously mentioned practices, this section consolidates and critically evaluates both traditional and modern strategies, highlighting their trade-offs, synergies, and research gaps. One of the most effective strategies is improving irrigation efficiency by adopting drip and deficit irrigation systems. These practices significantly reduce water losses compared to surface irrigation, thereby alleviating pressure on rivers and wetlands. However, while drip irrigation lowers water extraction, it may still promote intensive monocultures that reduce habitat heterogeneity and, in turn, biodiversity. A balance must be achieved between water-saving efficiency and ecological diversity. Agroecological practices, such as crop rotation, intercropping, agroforestry, and organic farming, not only lower the agricultural water footprint but also increase soil fertility, enhance pollinator diversity, and reduce chemical runoff [90]. These methods strengthen ecological resilience but often face scaling limitations due to labour intensity and market barriers. This gap requires policies and incentives to make biodiversity-friendly farming economically viable for Andean communities.

Traditional water management practices, including irrigation canals (acequias), terracing, and community-based water-sharing agreements, have sustained Andean livelihoods for centuries. Their strength lies in fostering collective governance and social cohesion, ensuring equitable water distribution even under scarcity. Yet these systems are increasingly vulnerable to glacier retreat and altered rainfall patterns, necessitating complementing them with scientific monitoring and adaptive planning. Recent technological advances, such as remote sensing, hydrological modelling, and water accounting frameworks, allow more precise measurement of water footprints at farms and watershed scales. For example, satellite-based evapotranspiration mapping in Peruvian catchments has improved monitoring of water use efficiency and biodiversity impacts [91]. However, these tools demand technical expertise and reliable data access, which are often lacking in rural Andean regions. Bridging this digital divide is a pressing research and policy challenge. Ultimately, the most promising path lies in hybrid approaches that integrate traditional governance with modern WFM tools.

In this study, human rights to water are understood as the universal entitlement to safe, sufficient, acceptable, physically accessible, and affordable water for personal and domestic use, as articulated in UN General Assembly Resolution 64/292 [5] and CESCR General Comment No. 15 (2002). Social equity refers to the fair and inclusive distribution of water across regions, communities, genders, and generations. Justice refers to governance frameworks that integrate human rights and equity while safeguarding ecosystems and cultural values [92]. International law now recognises water as a human right. In 2010, the United Nations Human Rights Council adopted a resolution recognising the right to water and sanitation as a human right in the General Assembly. This resolution says that every individual is entitled to adequate, safe, acceptable, physically accessible, and affordable water to meet their personal and domestic needs. It is not only a health and hygiene privilege; it also plays a fundamental role in the well-being of individuals and communities. The human right to water in coastal cities such as Lima, Ilo, Chancay, and Trujillo is increasingly compromised by declining Andean inflows, requiring integrated, rights-based governance between mountains and coasts.

Enforcement of the human right to water in Andean states faces persistent implementation constraints. Common challenges include fragmented mandates among national water authorities, environmental regulators, and subnational governments; limited budgets and technical capacity for monitoring and compliance; and weak sanctioning power when influential actors (e.g., mining, hydropower, agro-export) violate allocation rules or exceed discharge limits. Policy contradictions also emerge when constitutional or statutory recognition of water rights and environmental protections coexist with development policies that prioritise extractive concessions, large-scale irrigation expansion, or inter-basin transfers, creating gaps between rights “on paper” and realised access in practice. Empirical evidence shows that rights-based approaches can improve equity when they are coupled with enforceable institutional mechanisms. For example, in Ecuador, constitutional recognition of the rights of nature and water as a strategic public resource has supported community and Indigenous claims in páramo-fed watersheds, strengthening protections for communal drinking-water systems and upstream ecosystems [93]. In Peru’s Santa River basin, water conflicts linked to glacier retreat, mining pressures, and hydropower demand have motivated legal and institutional reforms focused on allocation rules and environmental oversight, illustrating both the potential and limits of rights-based governance in contested basins. These cases demonstrate that equity gains are most visible where legal recognition is matched with participatory enforcement, transparent allocation, and effective regulation of pollution.

Gender, migration, and intergenerational influences also shape equity outcomes in rights-based governance. Women are often the main providers of household water and community health, but are under-represented in formal water-user bodies and negotiation arenas; gender-inclusive governance thus influences both procedural equity (voice) and distributional equity (allocation). It may be weakened by migration, often driven by climatic stress, and by economic changes, where labour for community maintenance (‘faenas’) is eroded, along with disrupted local knowledge of water. Simultaneously, the outmigration of youth might accelerate intergenerational loss of knowledge in activities such as ‘amunas’ maintenance, ‘bofedales’ management, and rotational allocation, thereby lowering adaptive capacity in the long run [94]. Rights-based frameworks are thus reinforced by actions that enhance decision-making among women, flexible involvement of mobile households and intergenerational transfer based on local training and documentation and co-management.

For indigenous peoples of the Andes, water is not only a survival resource but also carries spiritual, cultural, and communal significance [92]. However, these worldviews are diverse and evolving. For example, Quechua groups in Cusco maintain ritual ties with springs (puquios) [95] and wetlands, while Aymara communities in Bolivia emphasise collective irrigation governance through ‘ayllu’-based systems [96]. Recognising this plurality avoids essentialising Indigenous perspectives and instead highlights how their practices adapt under shifting political, economic, and climatic pressures [2]. The constitutional treatment of the rights to water and their consideration as Indigenous rights have been controversial issues in prospective countries like Peru, Bolivia, Ecuador, and Colombia. Although notable contributions are being made in some countries and to some water bodies, such as in 2008 in Ecuador, where a constitution was adopted that establishes the rights of nature and Indigenous peoples concerning their territories, the implementation of these rights remains tenuous. In Peru, Indigenous water rights have received partial legal recognition; however, these rights are frequently undermined by national water policies that prioritise commercial interests such as large-scale mining and industrial agriculture, often at the expense of local and native communities [53]. The water management systems and traditional knowledge of Indigenous peoples developed over several centuries also form part of the ethical considerations in Indigenous water rights. These systems include irrigation canal management and community water-sharing agreements, grounded in Indigenous worldviews that treat water as a communal resource to be cared for and shared, rather than a commodity to be exploited. The realisation and recognition of native rights to water can diminish the unsustainability in fair water treatment in the Andes, enabling people to govern their water resources and safeguard their cultural universes.

Distributing water fairly is a major issue in the Andes, especially in remote and rural settlements. Such societies are sometimes prone to inaccessible clean water due to geographic inaccessibility, lack of infrastructure, and inability to fortify monumentally. Although urban populations can usually access water piping systems, rural and Indigenous populations in the Andean highlands often have limited or poor access to water supplies, e.g., rivers, streams or well water, which are often contaminated or simply inadequate to their demands. Rights-based approaches in the Andes have produced both successes and shortcomings. The human rights approach in the Andes requires the state and international organisations to cooperate not only to provide access to water, but also to make it accessible, affordable and safe. The Andean region faces persistent challenges, including political instability, lack of coordination among government institutions, and limited investment in infrastructure, all of which hinder universal access to clean water. Inadequate sanitation and poor water quality contribute to waterborne diseases, disproportionately affecting Indigenous populations and deepening health disparities. International organisations such as the United Nations, along with NGOs, play a critical role in supporting the right to water and advancing equitable distribution in remote areas. They assist in awareness creation and resource mobilisation and collaborate with the local community to develop and prescribe sustainable water solutions.

In this study, eco-efficient practices are defined as water-saving measures such as drip irrigation or pre-Incan ‘amunas’ that maximise productivity per unit of water [97], [98]. Sustainable methods include practices like rotational grazing in high-altitude ‘bofedales’, which maintain forage production while preserving hydrological functions [99]. Better management practices refer to strategies such as lining canals to reduce seepage losses or crop rotations that minimise evapotranspiration [98]. These distinctions help clarify how WFM translates into concrete interventions in the Andean region. New irrigation methods, such as drip irrigation and spray irrigation, are becoming instrumental in saving water and improving water efficiency [100]. Drip irrigation, in which water is delivered to the plant roots, reduces actual water loss because there is less evaporation of water and runoff. In this system, crops receive exactly the amount of water they require, thereby minimising waste and improving productivity. Another important water-saving technology is sprinkler irrigation, which can be applied in areas where drip irrigation is less feasible due to land characteristics or crop types. These systems distribute water uniformly across larger areas, reducing the total irrigation demand compared to conventional flood irrigation. Such technologies have been particularly valuable in the highland agricultural regions of the Andes that frequently face water scarcity. For example, in Peru, the successful adoption of drip irrigation in quinoa cultivation has enabled farmers to achieve higher yields while using less water. Beyond improving water-use efficiency, these technologies have also enhanced resilience by allowing farmers to sustain production during dry spells. Effective case studies can illustrate how water-efficient irrigation systems can transform the current way of farming in the Andes, not only sustaining farmers in their way of life but also ensuring that ecosystems within which these water bodies are located remain healthy [101].

However, high-efficiency irrigation systems also entail important trade-offs. While drip and sprinkler technologies reduce field-level water losses, they may decrease return flows that traditionally recharge downstream aquifers and wetlands. In closed or semi-arid Andean basins, reduced percolation can lower groundwater recharge, potentially affecting baseflows that sustain bofedales and coastal aquifers. Moreover, improved efficiency can incentivise agricultural expansion or intensification (the so-called “rebound effect”), whereby saved water is used to cultivate additional land or higher-value crops, thereby offsetting conservation gains. Stiffened monocultural systems can also decrease habitat heterogeneity and increase the use of agrochemicals, enhancing grey water footprints and ecological pressures [102]. For these reasons, modernisation of irrigation should be incorporated into basin-level allocation regulations and environmental water protection, so that the efficiency gains are translated into actual water savings and biodiversity gains.

Another important method for reducing the water footprint of agriculture in the Andes is selecting water-efficient crops. Less water is used to grow crops such as quinoa, known to grow better in high-altitude areas than conventional crops like maize and potatoes. Farmers can also minimise their water use by adopting drought-resistant varieties, thereby ensuring food security. In the Cordillera Blanca of Peru, the restoration of ancient ‘amunas’ has increased groundwater recharge and sustained dry season flows, supporting both agriculture and aquatic ecosystems [97]. Similarly, in Puno, community-managed ‘bofedales’ with rotational grazing regulate water flows while maintaining biodiversity and carbon storage. These examples show how WFM strategies grounded in both traditional and modern practices can generate tangible ecological and livelihood benefits. Moreover, reduced water consumption benefits not only by lowering irrigation costs but also by supporting local biodiversity, as native and climate-resilient crops are typically better suited to Andean environments.

Figure 3.

Comparative water footprint intensity of major crops cultivated in Andean and Andean-fed agricultural systems; figure data from Arjen et al. [41], values represent approximate total water footprints

Beyond crop selection, crop rotation remains a cornerstone of Andean farming systems, playing a vital role in water conservation. Rotating crops with different water and nutrient requirements helps maintain soil fertility, reduce reliance on artificial irrigation, and improve long-term soil water retention, as shown in Figure 3. The heatmap-style visualisation reflects relative differences in total water demand, integrating green and blue water components reported in the literature; higher colour intensity indicates greater water consumption per unit of yield, highlighting crop-dependent differences relevant for water footprint management and irrigation planning. Quinoa exhibits the lowest footprint (≈1500 L kg⁻¹), largely due to its reliance on green water and physiological tolerance to water stress; maize (≈1800 L kg⁻¹), wheat (≈2200 L kg⁻¹), and potatoes (≈2500 L kg⁻¹) show progressively higher water demands associated with irrigation dependence and climatic sensitivity. By contrasting these crops, Figure 3 supports the argument that crop selection is a critical lever for reducing agricultural water footprints in the Andes, particularly under conditions of declining dry-season water availability driven by glacier retreat and climate variability. Additionally, soil management practices such as mulching and organic manure application contribute to water conservation by reducing evaporation losses, increasing soil moisture content, and improving soil structure. The combination of all these practices enables streamlining water consumption, preserving soil quality, and minimising the overall water footprint of agriculture in the area [103].

The practice of water conservation among Andean communities has existed for several decades. Techniques such as terracing, canal irrigation, and aqueducts have enabled these people to manage their water resources efficiently, ensuring constant availability of water for both domestic use and agricultural activities. These practices are fundamental strategies for sustaining livelihoods under conditions of scarcity. A closer examination reveals that Indigenous practices and technical conservation approaches often share common objectives, even if expressed through different methods. For example, Andean terracing reduces runoff and soil erosion, mirroring modern soil and water conservation engineering that promotes slope stabilisation and moisture retention [104]. Similarly, communal irrigation canals (acequias) function not only as cultural institutions but also as decentralised systems of equitable water allocation and demand management, aligning with contemporary goals of participatory governance and environmental flow protection [92]. Ritualised water-sharing assemblies echo principles of adaptive co-management, ensuring seasonal adjustment of water allocations, much resembling scientific recommendations for dynamic allocation in the face of climate variability [92], [96]. By explicitly recognising these overlaps, WFM can be reframed as a hybrid system, where ancestral techniques provide legitimacy and social cohesion, while technical innovations such as drip irrigation, hydrological modelling, or remote sensing strengthen efficiency and monitoring [75], [98].

Bridging these two knowledge domains highlights that conservation goals such as soil fertility, biodiversity protection, and equitable access are already embedded in Indigenous systems and can be reinforced rather than replaced by modern science [2]. An illustrative example is terracing, widely practised in the Andean highlands, which mitigates soil erosion and surface runoff while retaining soil moisture and nutrients. Similarly, controlled canal irrigation systems, often built with local materials, channel water from nearby rivers and streams to agricultural fields [105]. When such ancestral practices are combined with modern technologies like drip irrigation and water-efficient crop management, they can substantially reduce the water footprint and enhance the sustainability of Andean agriculture. For instance, in several Andean regions, the integration of modern irrigation tools within existing community-based water rights systems has promoted more equitable water distribution and improved efficiency [106].

Reuse of treated wastewater is a new phenomenon in sustainable water use, especially in areas with water scarcity, such as the Andean highlands. Despite these benefits, wastewater reuse faces major barriers in the Andes. Infrastructure costs for treatment plants remain prohibitively high for many municipalities, and social acceptance is often low due to contamination concerns. In addition, national frameworks such as Peru’s Guidelines for Reuse of Treated Wastewater exist but are unevenly implemented. Digital technologies can support this strategy by integrating IoT-enabled water-quality sensors and predictive analytics to optimise reuse scheduling, ensuring treated water is applied when most needed during dry seasons. Linking recycling systems to digital monitoring platforms could also reassure communities by providing transparent data on water safety.

There are various situations in which treated wastewater may be utilised for non-edible purposes, such as crop production or landscaping, where water quality is not particularly strict. For example, in the Andean region, treated wastewater can be applied to cultivate fodder crops or to expand agricultural areas where drinking-water quality standards are not required [107]. This practice also reduces pressure on freshwater resources, providing farmers with a more reliable water supply during dry seasons. Nonetheless, wastewater treatment systems must meet strict health and environmental standards to prevent soil and water pollution and ensure long-term sustainability. Khan et al. [108] demonstrated that, with proper monitoring, treated wastewater can be safely reused in agriculture, supporting sustainable landscapes and reducing negative environmental impacts. The adoption of water recycling and treatment technologies not only curbs excessive freshwater use but also enhances water-use efficiency and reduces farming costs.