Management Of Transboundary Aquifers Research Articles

Hydrogeochemical assessment of groundwater in transboundary aquifers along the US-Mexico border and drinking water quality implications for Texas Colonias

The groundwater resources in transboundary aquifers are crucial to the development of involved nations. A unified governance strategy based on scientific data is essential for the management of transboundary aquifers. This study presents a comprehensive geochemical analysis of the groundwater quality of private wells along the US-Mexico border in Texas across three transboundary aquifer types. The concentrations of dissolved major ions, trace, and rare earth elements (REE) were measured, and the dissolved organic matter was spectroscopically characterized to evaluate the prevailing water-rock interactions, biogeochemical reactions, and anthropogenic contamination in the groundwater and their susceptibility to future contamination. Groundwater samples were collected from private wells (n = 22) from four representative counties within a section of the Texas-Mexico border (Maverick, Kinney, Dimmit, and Webb Counties). Three distinct aquifer types were revealed from the major ion composition, e.g., a carbonate aquifer within Kinney County (a part of Edwards-Trinity aquifer), an alluvial aquifer with prevailing reducing conditions within Dimmit and Webb Counties (a part of Carrizo-Wilcox aquifer), and an evaporite-rich aquifer within Maverick County. The concentrations of trace elements in the groundwater of each aquifer type were below the MCL of USEPA, however, excessive Sr concentrations were evident mostly in the evaporite-rich aquifer. Our results indicate dissolution of evaporites, and possible anthropogenic contamination may be responsible for the degradation of groundwater quality in Maverick County, raising concern for the viability of the aquifer in the future.

Transboundary Aquifer Management Across the Americas: Hydro-Diplomacy as an Accelerator of Adaptive Groundwater Governance Amid Climate Change Challenges

The management of transboundary aquifers across the Americas faces significant challenges, especially as climate change and population growth intensify groundwater stress. Groundwater use has increased to support domestic, industrial, and agricultural demands but has been extracted through unregulated withdrawals, leading to the severe degradation of aquifer health and transboundary frictions. This study focuses on how hydro-diplomacy can accelerate the adaptive governance of shared groundwater resources in three key regions: Canada–USA, USA–Mexico, and Mexico–Guatemala–Belize. We utilized a mixed methodology by integrating a transect approach, borrowed from ecology, into the field of geopolitics. To compare the hydro-diplomatic relations and groundwater governance across a continental gradient in the Americas, we conducted a literature review and employed the TWINS conflict–cooperation matrix to evaluate governance frameworks and hydro-diplomatic interactions across time. Our findings demonstrate that hydro-diplomacy plays a pivotal role in expediting agreements, fostering transboundary data sharing, and supporting participatory governance models. In particular, the presence of supranational bodies such as the International Joint Commission (IJC) between Canada and the USA has been effective in maintaining long-term collaboration through social learning and technical cooperation. Meanwhile, in regions like Mexico–Guatemala–Belize, the absence of robust institutions has hindered progress, with limited financial and knowledge-sharing networks. This study highlights the need for improved cross-border cooperation mechanisms and the establishment of common monitoring protocols to better manage aquifer resources under the pressures of climate change. The results support the development of more adaptive transboundary groundwater management strategies aligned with Sustainable Development Goal (SDG) 6.5.2 and call for broader geopolitical cooperation to address the complexities of groundwater governance.

Water Balance Calculation for a Transboundary Aquifer System between Estonia and Latvia

Groundwater management in transboundary aquifers is complex due to the hidden nature of groundwater and its intricate interactions with surface water. The overarching issue lies in the need for improved tools and strategies to manage transboundary aquifers effectively, given their critical importance to regional water resources and ecosystems. In addressing these challenges, this study focuses on a specific transboundary aquifer system between Estonia and Latvia, situated within the sedimentary rocks of North-East Europe. Here, we propose a conceptual model approach as a valuable tool for comprehending the hydrogeological characteristics of transboundary aquifers and supporting more efficient management strategies. Utilizing open-source software MODFLOW-6, our developed conceptual model integrates the aquifer system’s geological and hydrogeological framework and simulates groundwater flow under transient conditions. Our findings highlight a profound hydrological connection between groundwater and surface water, particularly within the first 200 m of the aquifer. Despite varying cross-border groundwater flows, collaboration remains vital for sustainable transboundary aquifer management, aligning with international agreements such as the Water Convention and the EU Water Framework Directive, benefiting similar systems.

The importance of transboundary aquifer management between Poland and Ukraine for the protection of common water

Transboundary hydrogeological units between Poland and Ukraine within the Bug and San River basins are identified, based on harmonized geological and hydrogeological data used for development of a numerical simulation of groundwater flows across the state border. This numerical model shows that the cross-border exchange of groundwater in aquifers takes place in a limited area and the flow pattern can be disturbed by the groundwater exploitation. Abstraction at current levels slightly increases the transboundary groundwater flow from Poland to Ukraine and minimally reduces the flow in the opposite direction, though not reversing the direction of water flow at the border. The simulated drawdowns do not have a transboundary range, but negative effects on surface water resources are noticeable. Estimates show that groundwater runoff to rivers decreased and infiltration losses through the riverbed increased. The quantitative status of the transboundary aquifers has not deteriorated significantly under the current exploitation but in the light of ambitious maximum allowable values for water abstraction, and in the absence of joint resource management, this problem will arise in the near future. Joint management should focus on a broader legal consensus, improvement of institutional relations, and integration of monitoring and groundwater status assessment systems.

Why do we need to care about transboundary aquifers and how do we solve their issues?

As the reliance on transboundary groundwater is increasing globally, it is important to understand and address the specific issues raised by the assessment and management of transboundary aquifers (TBAs). Building on 20 years of TBA experience and through a three-pillar framework (assessment, cooperation-collaboration, shared management), the key elements to addressing TBA issues are described, including a multidisciplinary approach, identification of hotspot zones, local vs border-wide approaches, appropriate funding models, and an increased recognition of the role and value of each TBA.

Governance and policy responses to anthropogenic and climate pressures on groundwater resources in the Greater Mekong Subregion urbanizing cities

Groundwater has become a major source of freshwater for supporting socio-economic development in the rapidly urbanizing cities of the Greater Mekong Subregion (GMS). Paradoxically, mindless groundwater withdrawals have led to enormous pressures on vital resources: socio-economic development, urbanization, climate situation as well as groundwater governance. Through a case study in Khon Kaen, Thailand - a rapidly urbanizing city in GMS - this study aimed to examine (i) the trends of socio-economic development and climate pressures on groundwater resources, (ii) how groundwater policies responded to extraction, use, and management of groundwater over the last two decades. Time-series data of groundwater extraction, groundwater level, climate, and socio-economic situation (2000–2019) were tested by Mann Kendal trend test and Sen's slope estimation to investigate the direction of the trends and their changes. We use Pearson correlation to assess the association between socio-economic development and groundwater withdrawals. Institutional and retrospective policy analyses were applied to analyze the institutional arrangements and the policy changes over time. The findings show the rapid socio-economic development and climate trends accelerate the groundwater extraction as well as groundwater depletion in Khon Kaen. The Royal Thai Government has implemented some measures to control groundwater extraction through groundwater decentralization processes to local governments. However, groundwater extraction was only reduced in the short term. The findings reflect a lack of effective policies and low institutional capacity as the key challenges of groundwater management in the study area. Consequently, the way forward requires the consideration of collaborative strategies among key actors to strengthen groundwater governance in the rapidly urbanizing area to balance groundwater use, socio-economic development, and climate resilience. Further, the capacity of groundwater governance should be enhanced at the local level beyond transboundary aquifer management to ensure sustainable groundwater extraction in the GMS region to respond to the sustainable development goals.

Investigating Management of Transboundary Waters through Cooperation: A Serious Games Case Study of the Hueco Bolson Aquifer in Chihuahua, Mexico and Texas, United States

Management of transboundary aquifers is a vexing water resources challenge, especially when the aquifers are overexploited. The Hueco Bolson aquifer, which is bisected by the United States–Mexico border and where pumping far exceeds recharge, is an apt example. We conducted a binational, multisector, serious games workshop to explore collaborative solutions for extending the life of the shared aquifer. The value of the serious game workshop was building knowledge, interest, understanding, and constituency among critical stakeholders from both sides of the border. Participants also learned about negotiations and group decision-making while building mutual respect and trust. We did not achieve consensus, but a number of major outcomes emerged, including: (1) participants agreed that action is called for and that completely depleting the freshwater in the shared aquifer could be catastrophic to the region; (2) addressing depletion and prolonging the life of the aquifer will require binational action, because actions on only one side of the border is not enough; and (3) informal binational cooperation will be required to be successful. Agreeing that binational action is called for, the serious games intervention was an important next step toward improving management of this crucial binational resource.

Full access The International Law Commission’s Draft Articles on Transboundary Aquifers: striking the appropriate balance between sovereignty and international cooperation

Groundwater is a vital resource that is largely out of sight and out of mind. Activities worldwide are rapidly increasing the pressure on this important but invisible freshwater resource, causing widespread quantity depletion and quality degradation. To prevent a future water crisis, the International Law Commission’s 2008 Draft Articles on Transboundary Aquifers became the first global instrument to address the management of transboundary aquifers, whether hydrologically connected to a system of surface waters or not. This article examines the progressive development of international law through the Draft Articles and considers the balance struck between territorial sovereignty and international cooperation in the context of groundwater resources. Reflecting on the various approaches towards sovereignty over shared natural resources, the history and development of Draft Article 3 on sovereignty, and the obligations of international cooperation which purport to limit State sovereignty, this article concludes that the appropriate balance has been struck, reflecting the theory of limited territorial sovereignty with hints of the notion of a community of interest.

A national border-based assessment of Malawi’s transboundary aquifer units: Towards achieving sustainable development goal 6.5.2

Study regionMalawi. Study focusThe adoption of the United Nations Sustainable Development Goal 6 in 2016 has triggered countries across the globe to assess and improve management and use of water resources. Monitoring of these resources is becoming increasingly important, and the management of transboundary water resources, in particular groundwater aquifers, required to meet SDG target 6.5.2, is lagging behind. It is vital to assess and manage these resources in a sustainable manner within an integrated water resource management approach. Transboundary aquifer assessments have largely focused on the regional scale which is not sufficient for countries to manage their transboundary aquifers effectively. This paper focuses on results of a national transboundary aquifer unit assessment in Malawi as a case study to support the countries plans for achieving Sustainable Development Goal 6.5.2.New hydrological insights for the region: We have identified 38 new transboundary aquifer units shared between Malawi and its neighbours. These results can form the basis for future transboundary aquifer management between Malawi and its neighbouring countries. We also highlight the current limitations of transboundary aquifer assessments and management that should be addressed to achieve SDG 6.5.2. These include institutional mechanisms, limited cross-border data sharing, limited groundwater monitoring, and a need to revisit the wording of the transboundary-focused SDG target and its indicators.

Spatial Data Management and Numerical Modelling: Demonstrating the Application of the QGIS-Integrated FREEWAT Platform at 13 Case Studies for Tackling Groundwater Resource Management

Because of the spatial nature of groundwater-related data and their time component, effective groundwater management requires the application of methods pertaining to the Information and Communication Technologies sector, such as spatial data management and distributed numerical modelling. The objective of this paper is to demonstrate the effectiveness of the QGIS-integrated FREEWAT platform and an approach combining spatial data management and numerical models to target groundwater management issues. FREEWAT is a free and open source platform integrated in a Geographic Information System environment and embedding tools for pre- and post-processing of spatial data and integrating numerical codes for the simulation of the hydrological cycle, with a main focus on groundwater. To this aim, this paper briefly presents the FREEWAT platform, introduces the FREEWAT approach, and showcases 13 case studies in European and non-European countries where the FREEWAT platform was applied. Application of the FREEWAT platform to real-world case studies is presented for targeting management of coastal aquifers, ground- and surface-water interaction, climate change impacts, management of transboundary aquifers, rural water management and protection of groundwater-dependent ecosystems. In this sense, compared to other existing software suites, FREEWAT allows data analysis and visualization to accomplish each step of the modelling workflow, i.e., from data analytics, to conceptual model definition, to numerical modelling and reporting of results. The presented experiences demonstrate that improved access to data and the portability of models and models’ results can help to promote water sustainability from the local- to the basin-scale. Furthermore, FREEWAT may represent a valuable tool to target the objective of increasing the capabilities of public authorities and private companies to manage groundwater resources by means of up-to-date, robust, well-documented and reliable software, without entailing the need of costly licensing, nowadays seldom affordable by public water authorities. Based on the strengths highlighted, the FREEWAT platform is a powerful tool for groundwater resources management, and for data collection, sharing, implementation and comparison of scenarios, for supporting planning and decision-making.

Review: Challenges and opportunities for sustainable groundwater management in Africa

Groundwater plays a fundamental yet often little appreciated role in supporting economic development and human well-being in both urban and rural environments, as well as supporting many aquatic ecosystems in Africa. Thus, groundwater has high relevance to the development and well-being of Africa, if adequately assessed and sustainably exploited. Whilst the potential for groundwater-resources development continues to be reported in the literature, a quantitative understanding of these issues remains poor. The objective of this paper is to highlight the main groundwater issues and problems in Africa and the current and expected opportunities for sustainable groundwater management. This will be done through the review of existing knowledge of groundwater resources and of ongoing and planned groundwater management programs and initiatives. Groundwater resources in Africa face increasing threat of pollution from urbanisation, industrial development, agricultural and mining activities, and from poor sanitation practices and over-exploitation due to increasing demand to meet human and agricultural needs. However, despite the existence of a number of groundwater management challenges, groundwater resources in Africa are still generally under-developed and can meet the various needs in a sustainable manner if better managed. Thus, strategies to ensure sustainable development and management of groundwater resources need to be put in place. These include establishment of groundwater monitoring systems, understanding of the groundwater–aquatic ecosystem relationships, management of transboundary aquifers, addressing climate-change impacts on groundwater, assessing the impact of increased pumping from various types of aquifers on sustainability of groundwater abstraction, and capacity building in groundwater management.

Development of a Protocol for the Karst Water Source Protection Zoning: Application to the Classical Karst Region (NE Italy and SW Slovenia)

Although karst aquifers are highly vulnerable and represent an important water resource, they are often inadequately protected. Furthermore, national water resource protection policies lack precision regarding the criteria for delimitation of source protection zones in karst. Usually either vulnerability assessment or travel time is considered. The proposed integrated protocol considers both. It is specifically designed for large karst aquifers where i) an additional distinction between areas of different liability to contamination within the aquifer, and ii) a certain generalisation of protection classes should be made for practical reasons. The protocol includes a detailed description of the separate steps of the protection zoning procedure. Information obtained from both artificial and natural tracers is used to account for the variability of groundwater flow under different hydrologic conditions. Analysis of groundwater physico-chemical parameters time series is better employed under high flow regimes and analysis of artificial tracers breakthrough curves under low flow conditions. Source protection zones are divided into three levels of protection, which should be further generalised, validated and adjusted to land use plans. The protocol has been applied to the Classical Karst Region transboundary aquifer (NE Italy and SW Slovenia). The results enable a uniform delineation of protection zones encompassing water sources that have not been protected to date, and improve the understanding and management of transboundary aquifers. The proposed protocol can be used in other karst aquifers, and adjusted to national protection legislation and spatial planning frameworks.

The Guarani Aquifer System (Gas) and the Challenges for Its Management

It is a huge reserve in South America region and it is considered one of the largest sources of groundwater on the planet. The GAS has strategic value for its countries, especially in a context of increasing scarcity. Its size, its physical and political complexity, as well as its “invisibility” and insufficient treatment in the international scenario, constitute some of the challenging elements for management. The article will, in the first instance, summarize the management cases for transboundary aquifers in the world. Subsequently, a physical and political characterization of the GAS will be made, so that, finally, the existing challenges for the management of this resource will be presented. In order to carry out this work, a bibliographical review of the articles and documents published in recent years concerning the management of transboundary aquifers in the world was carried out, as was done with respect to the Guarani Aquifer and its international framework.

Social tipping points in global groundwater management.

Groundwater is critical to global food security, environmental flows, and millions of rural livelihoods in the face of climate change 1 . Although a third of Earth's largest groundwater basins are being depleted by irrigated agriculture 2 , little is known about the conditions that lead resource users to comply with conservation policies. Here we developed an agent-based model 3,4 of irrigated agriculture rooted in principles of cooperation 5,6 and collective action 7 and grounded on the World Values Survey Wave 6 (n = 90,350). Simulations of three major aquifer systems facing unsustainable demands reveal tipping points where social norms towards groundwater conservation shift abruptly with small changes in cultural values and monitoring and enforcement provisions. These tipping points are amplified by group size and best invoked by engaging a minority of rule followers. Overall, we present a powerful tool for evaluating the contingency of regulatory compliance upon cultural, socioeconomic, institutional and physical conditions, and its susceptibility to change beyond thresholds. Managing these thresholds may help to avoid unsustainable groundwater development, reduce enforcement costs, better account for cultural diversity in transboundary aquifer management and increase community resilience to changes in regional climate. Although we focus on groundwater, our methods and findings apply broadly to other resource management issues.

The Guarani Aquifer Agreement and Transboundary Aquifer Law in the SADC: Comparing Apples and Oranges?

International law governing transboundary aquifers is considerably underdeveloped, with only a handful of bilateral and multilateral agreements governing specific aquifer systems to date. However, the significance of transboundary aquifers in addressing water security concerns is gaining recognition, and dialogue discussing the future of the international legal framework is growing in importance. Contributing to this dialogue, we seek to compare different legal instruments applicable to the management of transboundary aquifers in different regions. We draw from the experience of the processes that led to an established transboundary agreement in one region, and compare it to another region that is yet to establish a formal legal instrument. Specifically, we compare the Guarani Aquifer System in Latin America with international legal instruments applicable to the management of transboundary aquifers in the Southern African Development Community (SADC). We identify several trends arising from the management of the Guarani Aquifer System that could have potentially valuable input for SADC countries currently embarking upon the initial stages of the management of a transboundary aquifer. Central to this article is the underlying question of whether these international legal instruments, which are placed in dramatically different contexts, can be compared in the first place. We conclude that such a comparison is useful only if undertaken as a process of knowledge acquisition, as such a broad comparative exercise is limited in its ability to produce direct policy recommendations. Gaining knowledge of regional governance practices in relation to differing aquifer characteristics is particularly important in this underdeveloped area, especially as discussions regarding the future for transboundary aquifer law are gaining momentum at the international level.

The Law of Transboundary Aquifers: Many Ways of Going Forward, but Only One Way of Standing Still

The international community has been considering international legal norms and policies for the management of transboundary aquifers for more than ten years. In 2008, the International Law Commission provided a framework with the adoption of the Draft Articles on the Law of Transboundary Aquifers, which are now formally annexed to a United Nations General Assembly (UNGA) Resolution. Since 2008, the topic of the law of transboundary aquifers has thrice been placed on the agenda of the UNGA Sixth Committee with a specific mandate to discuss the future form of the Draft Articles. This article explores the options before the international community regarding the future form of the Draft Articles and considers the possible advantages and disadvantages of each option. The article also discusses the extent to which the actual form of the Draft Articles matters in itself, or whether their impact ultimately will depend on other factors.

A Human Right to Groundwater?

Within a few months in 2010, both the UN General Assembly and the Human rights Council affirmed a human right to safe drinking water. The present paper purports to identify the impact, if any, of these declarations of an already-existing or emerging right to water and its repercussions on the proper management of transboundary aquifers, a shared resource, which the International Law Commission sought to regulate in its 2008 Draft Articles on the Law of Transboundary Aquifers. Reviewing existing binding and non-binding instruments and related State practice, I argue that there exists today a mature right to clean water, encompassing specific obligations for States to provide and enforce verifiable standards in a market environment. Although the law of transboundary aquifers is in a nascent form, there is no reason not to import the polished quality requirements of the right to water in order to further identify and fulfill the basic human needs, it has set out to address. The achievements of the human rights field may and must be transferred into the emerging water law, in order to educate and clarify its concepts and ensure its effective implementation.

A Human Right to Groundwater?

AbstractWithin a few months in 2010, both the UN General Assembly and the Human Rights Council affirmed a human right to safe drinking water. The present paper purports to identify the impact, if any, of these declarations of an existing or emerging right to water and its repercussions on the proper management of transboundary aquifers, which the ILC sought to regulate in its 2008 Draft Articles. Reviewing existing binding and non-binding instruments and related State practice, I argue that there exists today a mature right to clean water. Although the law of transboundary aquifers is in a nascent form, there is no reason not to import the polished quality requirements of the right to water in order to further identify and fulfil the basic human needs it has set out to address. The achievements of the human rights field may and must be transferred into the emerging water law.

国際レベルの越境地下水の管理のあり方 国連国際法委員会からの提言

One of the important functions of the United Nations General Assembly is to codify the international law in order to establish the rule of law for the cause of justice and order of the international community. The UN International Law Commission is the subsidiary organ of the UN General Assembly to prepare the basic documents for such codification. The Commission embarked on the work of formulating draft articles on the law of transboundary aquifers in 2002. The author was appointed as the Special Rapporteur for this project and the Commission was able to submit to the UN General Assembly its final report in 2008. The UN General Assembly is to make its decision in 2011 on how to proceed to transform these draft articles into the treaty. The most of the States have transboundary aquifers with their neighbours. The groundwater is an indispensable life support resource for the mankind and also the most heavily exploited single resource for which no alternative resource exists. The establishment of legal norms for the proper management of transboundary aquifers, protection of environment, international cooperation and pacific settlement of disputes among the States sharing the aquifers is urgently required by the international community. This paper is designed to present the background of the issue, how the draft articles are formulated in cooperation with hydrogeologists and groundwater administrators, main elements of the draft articles, positions of various States and the future prospect of the draft articles.

Economics of Transboundary Aquifer Management

This paper presents a general model of optimal water management for a transboundary aquifer under three different management approaches: cooperative, noncooperative, and myopic. Comparing the results from the approaches, we find the cooperative solution, where a single management plan is executed for all parts of the aquifer, results in the highest level of net social welfare, followed by the noncooperative and then the myopic. The trade-offs we find for the higher levels of welfare are lower use levels in the earlier periods. We present a short discussion of factors that can increase the inefficiencies of the models and suggest directions for future research.