Archive for the ‘South America’ Category

Dr. Maria Querol: The UN Watercourses Convention and South America

Thursday, August 21st, 2014

The following post by Dr. Maria Querol is the ninth in the series of essays related to the entering into force of the 1997 UN Watercourses Convention (see links to all of the essays here). Dr. Querol is an international law consultant with a vast background in international water law. She can be reached at maria.querol [at]



Although the 1997 UN Watercourses Convention (UNWC) has finally entered into force, not one South American country is among its State Parties. Whilst Brazil, Chile, Uruguay and Venezuela voted in favour of its adoption at the UN General Assembly (UNGA), Argentina, Bolivia, Colombia, Ecuador, Paraguay and Peru all abstained. Paraguay and Venezuela were the only states from the region to sign the Convention, in 1997 and 1998 respectively. Nevertheless, neither has made any attempt to ratify it.

Many arguments have been presented to justify this flagrant absence, mainly focusing on the concern of South American states regarding challenges to their sovereignty over water resources flowing through their territories. However, this is not the only factor to be considered when analysing the region’s position on this topic.

Multilateral transboundary water treaties of South America

South American states have a history of concluding international treaties to regulate the management of their shared watercourses. This long-standing tradition favors the implementation of specific mechanisms and international water law norms over more general regimes. While most of these agreements are bilateral, there are four exceptions: the 1969 Treaty of the River Plate Basin, the 2010 Guarani Aquifer Agreement, the 1978 Amazon Cooperation Treaty, and the 1995 Agreement constituting the Tri-National Commission of the Pilcomayo River Basin.

International Basins of South AmericaThe Plate Basin Treaty entered into force for Argentina, Bolivia, Brazil, Uruguay and Paraguay on 14 August 1970.  It operates as an umbrella for other more specific agreements, both bilateral and multilateral, that have been concluded with regard to particular transboundary watercourses within the basin. Article VI of this agreement foresees the possibility that its Contracting Parties may conclude specific, partial, bilateral, or multilateral agreements designed to develop the basin. Accordingly, the Guarani Aquifer Agreement was concluded within the framework of the Plate Basin Treaty. Thus, the basin is regulated with an intergrated approach, both from a general and a more specific standpoint.

Transboundary watercourses are regarded in the region as shared natural resources. This view was particulary emphasized by both Argentina and Uruguay in the 1975 River Uruguay Statute and reaffirmed in 2010 in the Pulp Mills case before the International Court of Justice (ICJ). In this regard, Argentina argued in its memorial to the Court that “[t]he shared nature of the River Uruguay is also apparent from the fact that obligations are imposed on Argentina and Uruguay at an international level. The 1975 River Uruguay Statute is actually a repository for th[ose] international obligations”. Those obligations comprise the rules of no significant harm, equitable and reasonable use, and prior notification. It is important to bear in mind that these general norms are only applicable to the use and protection of shared natural resources as long as the states sharing the resource have not implemented a more specific conventional regime. Accordingly, Argentina also declared that while the River Uruguay Statute had been concluded 22 years before the UNWC was adopted by the UNGA, “the Statute provides for the establishment of a system of co-operation which is far more rigorous than that laid down by the Convention.”

The Amazon Cooperation Treaty was adopted by Bolivia, Brasil, Colombia, Ecuador, Perú, Suriname and Venenzuela to promote equitable and mutually beneficial results in the Amazon territories under their respective jurisdictions. It entered into force on 12 August 1980. The no harm rule and the reasonable and equitable principle are enshrined in Article I of the agreement. The no harm rule is also implicit in Article XVI as it stipulates that the decisions and commitments adopted by the State Parties to the treaty shall not be to the detriment of projects and undertakings executed within their natural territories, in accordance with international law. In addition, Article V prescribes the rational utilization of the water resources of the Amazon System. Periodic exchange of information among all the State Parties is also provided for in Articles I, VII and XI.

By virtue of an amendment to Article XXII of the Amazon Cooperation Treaty, the Organization of the Treaty of Amazon Cooperation was created with the view of further strengthening and ensuring the more effective implementation of the goals of the Treaty. The existence of an international legal entity directly regulated by public international law no doubt facilitates the realization of projects and can provide guidance for the rational utilization and sustainable management of shared water resources in the Amazon region.

Although the Amazon Cooperation Treaty does not prescribe a dispute resolution mechanism, State Parties can agree to submit their disputes to an arbitral tribunal or a permanent judicial organ such as the ICJ. They can also resort to a political dispute resolution method such as mediation or good offices. In any case, states are always bound by the customary obligation to negotiate a solution to their disputes in good faith.

Transboundary water management in South America

Unlike the practice in other regions of the world, discussions over shared water resources in South America, more often than not, take place under a cordial atmosphere. Although information exchange among states does take place in the region, the necessary data may be scattered around in different institutions, in which case its collection can prove quite burdensome. With reference to dispute resolution, South American states have been resolving their issues through direct negotiations and in some cases, as between Argentina and Uruguay, through the ICJ. Whilst progress has been made in terms of cooperation and knowledge over the management of shared surface water resources, this is not the case with regards to all shared groundwater. A first step forward has indeed been taken with regards to the Guarani Aquifer. But, further in-depth knowledge is necessary to provide a more complete scenario of all the possible consequences of human action related to transboundary groundwater resources.

Currently, South American states do not appear to have an immediate interest in a universal framework treaty to regulate the management of their transboundary water resources. Rather, they would prefer to continue resorting to their existing bilateral and multilateral agreements and to applicable customary norms in the absence of such treaties. They even count on international organizations to help implement their preferred management regime in the case of the Amazon Basin, and through a framework agreement for the Plate Basin.

This does not mean that the UNWC will have no value to South America. To the extent that the Convention codifies general international rules, its norms are binding on all states of the international community, including those of South America. In addition, the entry into force of the UNWC might foster the development of new customary norms in areas not yet covered by the existing regional treaties and could prove very influential in the interpretation of those particular treaties.


The Silala Basin: One of the Most Hydropolitically Vulnerable Basins in the World

Thursday, October 27th, 2011

A few months ago, Brendan Mulligan and I published a paper entitled “The Silala/Siloli Watershed: Dispute over the Most Vulnerable Basin in South America in the peer-reviewed International Journal of Water Resources Development. The dispute, pitting Bolivia and Chile, provides a fascinating case study involving both transboundary surface and ground water resources. Of particular interest, it also involves an artificial watercourse traversing the border that may defy application of international water law to the controversy. In 2007, UNEP named the Silala watershed the only “high risk” basin in South America and “one of the most hydropolitically vulnerable basins in the world.”

The dispute focuses on water flowing across the Bolivian-Chilean border in the Atacama Desert via a canal constructed in the early 1900s by Antofagasta & Bolivia Railway Company, a Chilean mining operation, per a concession granted by the Bolivian Prefecture of Potosí. Bolivia claims ownership over the Silala River on grounds that the river originates from springs on its side of the border and that the Silala’s waters are transported artificially to Chile; in essence, Bolivia denies the existence of a Silalar river. In 1997, the Bolivian government revoked the concession on grounds that the waters had long been used for purposes that were different than those agreed to in the original agreement. It also sought to awarded a new 40-year concession to the Bolivian firm DUCTEC SRL for $46.8 million, established a military base on the banks of the Silala River, publicly discussed a plan to bottle the river’s water and sell it with the slogan “Drink Silala water for sovereignty,” and conducted a feasibility study for a hydroelectric plant on the Silala just inside Bolivian territory (see Bloomberg article). At one point, Bolivian officials asserted that any negotiations with Chile should guarantee Bolivia access to the Pacific Ocean (see Spanish-language article), a demand suggesting that the issues surrounding the Silala are not entirely water-focused.

In contrast, Chile bases its ownership claims on grounds that the Silala’s waters were never diverted from its original channel, but rather that the canal works merely augment the natural flow of the Silala River. Hence, Chile argues that the Silala is and always has been a transboundary river subject to international water law. Moreover, it contends that it need not pay for the use of the Silala and that Bolivia’s rescission of the original concession, as well as Bolivia’s awarding of the more recent DUCTEC concession, were illegal. It is noteworthy that while Chile voted in favor of the 1997 Watercourses Convention, Bolivia abstained from the vote and neither has signed or ratified it. Although the two governments have attempted to resolve the dispute, including drafting a bilateral agreement on the use of the waters of the Silala, it remains unresolved.

The applicability of international water law to the Silala scenario depends largely on whether or not the Silala River is described as a natural transboundary watercourse. A manufactured river, in the form of canals or other man-made systems, would not fall within the rubric of international water law since, by definition, such water bodies are proprietary and subject to the agreements that created them. Moreover, international water law does not apply to surface runoff flowing in a marginally defined or in undefined channel (e.g., surface runoff) regardless of whether or not the flow crosses an international boundary.

In the case of the Silala Basin, most of the spring flow is captured by artificial channels, constructed by the mining interests under its 1908 concession from the Bolivian Prefecture of Potosí and that cross into Chile via the principal canal. This would suggest that the water in the canal is subject solely to the terms of the concession agreement rather than to international water law. And when Bolivia rescinded the concession, the waters’ ownership reverted back to Bolivia.

Nevertheless, geological and topographical evidence (including onsite evaluations conducted by my co-author, Brendan Mulligan), as well as certain historical material, indicate that prior to canalization, the Silala springs flowed naturally across the Bolivian-Chilean border in approximately the same path as the principal canal. If this proves true, application of international water law is still unclear since we would have a transboundary river that was captured and canalized for private use.

Chile might argue that the concession trumps international water law since international law allows for the creation of agreements deviating from international standards so long as the deviations do not violate jus cogens (peremptory international norms). On the other hand, Bolivia may contend that the concession was a license revocable at the will of the licensor (Bolivia). If this latter analysis holds, then the rules for the basin reverted back to the default norms of international water law when the Bolivian government revoked the concession in 1997.

Still, to the extent that the flow of the pre-canalized Silala was intermittent rather than perennial, applicability of international norms also may be tenuous. The substantive rules of international water law can be understood, in part, as rules of liability. In other words, violation of the rules mandates the imposition of responsibility and recompense. Violation of the rules, however, can only occur where human actions interfere with the natural flow of the watercourse. Where a river fails to flow for natural reasons, as an intermittent stream is wont to do, no liability may be imposed. Moreover, the absence of state practice or examples in which international water law norms were applied to an intermittent stream suggests that this scenario is, at best, unresolved. Hence, to the extent that prior to canalization water in the Silala flowed across the Bolivian-Chilean border only intermittently, international water law principles may not be applicable to the present dispute.

Further complicating the scenario is the presence of an interrelated transboundary aquifer. As noted above, the Silala River is fed by springs in Bolivia. Those springs, however, emerge from the Silala Aquifer, which is believed to traverse the Bolivian-Chilean border. Unfortunately, as little as is known about the topography and geology of the Silala River Basin, even less information is available about the underlying aquifer. In addition, international law applicable to transboundary ground water resources is still in its infancy and there are only a few examples of state practice from which lessons can be drawn (see my article on Managing Buried Treasure Across Frontiers: The International Law of Transboundary Aquifers).

Whether additional facts and scientific information will be forthcoming from the parties or from independent sources is presently unclear. Moreover, even with such information, international water law, whether for transboundary surface or ground water resources, may not have a ready solution. As is often the case in disputes over shared water resources, negotiations may provide the most optimal solution for this most hydropolitically vulnerable of basins.

Conference on the Guarani Aquifer Agreement

Monday, February 14th, 2011

The signing of the Agreement on the Guarani Aquifer [Spanish] [Portuguese] on August 2, 2010, evidenced the continued progress being made in the pursuit of greater harmony in global hydro diplomacy (see my review of the agreement). True, South America is not lacking in fresh water resources. Yet, the effort by the overlying nations (Argentine, Brazil, Paraguay, and Uruguay) is laudable for its peaceful and cooperative approach. The four countries are now involved in the ratification process and in  negotiations over  institutional aspects, including discussions regarding an annex to the Agreement on arbitration procedures. How will these nations implement this agreement? What additional steps should they take?

Francesco Sindico, currently at the University of Surrey, Guildford, United Kingdom, along with colleagues Ricardo Hirata of the Centro de Pesquisas de Água Subterrânea–Instituto de Geociências da Universidade de São Paulo (CEPAS – IGc/USP) and Geroncio Rocha of the Secretaria do Meio Ambiente do Estado de São Paulo, is organizing a conference – “The Management of the Guarani Aquifer System: An Example of Cooperation” – in São Paulo, Brazil 21-23 September 2011. The deadline for abstract submission is 30 April 2011. Three conference sessions will address:

  1. An assessment of the scientific knowledge on the GAS
  2. Current use and protection of the Guarani Aquifer System
  3. The GAS and regional cooperation

For further information please see the full call for papers at:

Hydraulic Harmony or Water Whimsy? Guarani Aquifer Countries Sign Agreement

Thursday, August 5th, 2010

Last week it was the Nile Basin riparians [see here and here]. Now it’s the countries overlying the Guarani Aquifer. On August 2, 2010, the four nations overlaying the massive South American aquifer – Argentine, Brazil, Paraguay, and Uruguay – signed the Agreement on the Guarani Aquifer [Spanish] [Portuguese] in San Juan, Argentina (original text can be found on the Brazilian Ministry of Foreign Relations website). Has humanity finally reached its senses and decided to pursue global hydraulic harmony?

It is unfortunately unlikely that a global era of hydro-cooperation is at hand. Moreover, a review of this new Guarani instrument reveals a bare-bones agreement that contains less than ideal cooperative mechanisms. In particular, the agreement places great emphasis on individual states’ right while limiting obligations to cooperate and jointly management the aquifer. Article 2, for example, affords the parties the right of exclusive dominion over the portions of the aquifer that underlay each nation, while Articles 1 and 3 evince similar notions of sovereign rights. The idea that a state can have sovereign rights over a water body (or a portion of that water body) that flows across an international border harkens back to the long-discredited Harmon Doctrine. As international water law expert and former UN International Law Commission member, Dr. Stephen McCaffrey, modestly stated in a 2009 law review article [The International Law Commission Adopts Draft Articles on Transboundary Aquifers, Amer. J. of Int’l Law, Vol. 103, pp. 272-293 (2009)], where “the subject matter is something that moves from one state to another, from underground to surface, from surface to atmosphere, and so on in the hydrologic cycle, the notion that states have sovereignty over it seems a far from perfect match.”

In contrast, the Guarani Agreement places few limitations on sovereignty in relation to the rights of other parties. While it does contain provisions alluding to well-known international water law principles that could moderate the problems associated with sovereign claims over fresh water resources (e.g., principles of reasonable and equitable use [Arts. 3 & 4] and of no significant harm [Arts. 3, 6, & 7]), it merely references these notions without providing definitions or elaboration. In other words, the Guarani nations agreed mostly to leave each other alone in their respective Guarani-related territories and hydro-activities and only modestly agreed to cooperate.

Yes, the four nations did agree to share information generated about the aquifer (Arts. 9 & 12) as well as to notify each other of planned measures that may result in a transboundary impact (arts. 9, 10, & 11). And there is some language on the conservation and environmental protection of the Guarani (Art. 4) and the need to identify critical areas, especially in border regions, that require special measures (Art. 14). However, the language used in these provisions leaves quite a bit of room for interpretation and suggests that the parties themselves could not agree on the extent to which they want to cooperate. Similarly, the absence of any language describing the responsibilities and authority of the commission that is to be created under Article 15 intimate the creation of a paper tiger.

Notwithstanding its shortcomings, the Guarani Agreement can still be regarded as an important milestone in the world of international water law. Even in its less-than-ideal formulation, it constitutes progress in the effort to have more nations cooperate over shared fresh water resources. At the very least, it is an agreement for some measure of cooperation. If the four Guarani nations actually ratify the instrument (which appears likely), they will join a very small club composed of states who are party to a cross-border ground water treaty. The number of these treaties can be counted on one hand and include the complex management mechanisms governing the use of the Genevese Aquifer [French and unofficial English translation] along the French-Swiss border, and the rudimentary consultative and data-sharing agreements implemented for the Nubian Sandstone and Northwestern Sahara aquifers in North Africa. Given the dearth of treaties over transboundary aquifers (in comparison with the thousands of agreements over transboundary rivers and lakes), and the fact that there are at least 273 transboundary aquifers globally and that millions of people around the world rely on transboundary aquifers for their sustenance and livelihoods, the Agreement on the Guarani Aquifer is still a welcomed development.