Think about what you drank today. Odds are, you drank water at some point.

For most of us, particularly in more developed countries, water might come from the tap, a drinking fountain, or plastic bottles. We have become disassociated from our water sources on an individual scale. This does not mean, however, that they have become any less important. On the contrary, water sources – both surface and groundwater – are becoming more stressed, with pressures from rapid population growth, economic development, and global change, to name a few. Furthermore, much of the world’s usable freshwater resources are shared between two or more countries, which adds political, social, cultural, and economic complexities to our water consumption.


There are 310 international river basins globally that cover almost half of the world land surface (excluding Antarctica), and there are at least 592 transboundary aquifers that underlie about 20% of the world’s land surface1. A river basin – also known as a watershed or catchment – is an area of land that sends all the water falling within it to a common outlet. It becomes internationally shared – or transboundary – if an international political border runs through that area. Similarly, if the plan view area of an aquifer – a permeable geologic layer that contains and transmits water – is crossed by an international political boundary, it is also considered a transboundary aquifer. The necessity of securing water resources to respond to human, economic, and environmental needs at all scales emphasizes the need for transboundary water cooperation, although this proves to be a complex challenge.

Cooperation can allow countries to identify common interests and develop strategies and actions that can provide mutual benefits to the basin and/or aquifer countries. These benefits can affect various scales, ranging from improved water quality for better human and ecosystem health to power generation and exchange that benefits thousands of households and industries.

If cooperation can provide bountiful benefits, then why don’t countries always cooperate? Power, security, geography, hydrology, politics, and more can inhibit, discourage, and prevent countries from cooperating and contribute to conflict between them.


Therefore, transboundary water cooperation is enshrined in the United Nations 2030 Agenda for Sustainable Development and its 17 Sustainable Development Goals (SDGs), which seek to increase the scale, ambition, and state of global sustainable development. Goal 6 of the Agenda aims to “ensure availability and sustainable management of water and sanitation for all.”2 To achieve this, several targets have been set that are measured by indicators. Target 6.5 calls for the implementation of “integrated water resources management at all levels, including through transboundary cooperation, as appropriate.” It is measured by two indicators, one of which is SDG Indicator 6.5.2, which accounts for the “Proportion of transboundary basin area with an operational arrangement for water cooperation.” An arrangement (i.e. a treaty, convention, agreement, Memorandum of Understanding) over a transboundary basin, whether surface water or groundwater, is considered operational when there is a river basin organization, regular meetings, regular data and information exchange, and joint management plan(s) or objectives.

Target 6.5 and SDG Indicator 6.5.2 present a unique opportunity for international policy to encourage countries to cooperate over their transboundary waters; however, the structure of the indicator and the aspects of cooperation that are endorsed could promote a prescriptive conceptualization of cooperation over shared waters. This is what drove us to test the methodology of the indicator, in order to evaluate its ability in measuring transboundary water cooperation and better understand how the indicator will be applied.

Through three national overviews that calculate the indicator value for Bangladesh, Honduras, and Uganda, and a global overview that evaluates the methodology across all countries, we were able to consider the indicator through specific national contexts and through a broader global perspective.  We found that in some instances the indicator shows that there is no operational cooperation occurring in a country. For example, both Bangladesh and Honduras have no transboundary area under an operational arrangement for cooperation. However, this does not mean that the two countries do not have any practical cooperation with their neighbors occurring over their shared waters. Indeed, Bangladesh and India have a signed treaty to share the waters of the Ganges River, as well as other mechanisms for cooperation, but the mechanisms do not meet the requirements of the indicator. Whereas, the indicator value for Uganda was calculated to have 90% of its transboundary basin area under an operational arrangement for cooperation.


Globally, we can see that countries in Europe, Africa, and North America have the highest proportion of transboundary basin area with an operational arrangement for cooperation. The Middle East, Asia (with some notable exceptions), and the Pacific region have the lowest proportion of transboundary basin area under such arrangements.

Through our analysis, we found that the indicator has several strengths and limitations that users – including governments, policy-makers, water management organizations, researchers, and others – should be aware of when reporting and acting on the results. An operational arrangement as defined will guide countries in meeting their obligations in international conventions. Furthermore, research has shown that when countries have adequate capacity, such as the procedural elements comprising an operational arrangement for cooperation, there is a reduction in the potential for conflict. The indicator presents a straightforward, singular value that can be quoted and easily tracked for progress. However, as noted above, this value does not capture all the practical cooperation that is occurring. Therefore, it is important to disaggregate the indicator’s value by the individual criteria that composed it, for a better reflection of the cooperation processes that are taking place.

Developing a sole global indicator for measuring transboundary water cooperation is a challenging task, particularly because of the political nature and complexities of international relationships over shared waters. Therefore, there are several limitations in the methodology of SDG Indicator 6.5.2. The indicator value – the percent of a country’s area that has or does not have an operational arrangement for cooperation – is a simplistic “yes or no” representation of cooperation. This means that cooperative efforts that do not meet all the criteria to answer “yes” are marked as “no” operational arrangement for cooperation, even if cooperation in other forms is occurring. The criteria of the indicator also have a strong emphasis on the legal and procedural components of cooperation. While these are an important aspect of cooperation, other aspects such as substantive issues and political and social context are essential for cooperation to develop and last.

Ultimately, SDG Indicator 6.5.2 is a first-step, monitoring tool that countries and international organizations can use to raise awareness on the importance of transboundary water cooperation. Furthermore, it helps to gather information at a global level and is generating interest by governments to develop cooperative processes over their shared waters. The SDG Indicators will be measured, and some of their methods likely revisited during the 15-year timeframe of the 2030 Agenda, meaning there is potential for the methodology to be improved, with inputs from researchers and feedback from countries and policy-makers as they use and monitor the indicator in comparison with their own efforts towards transboundary water cooperation.

These findings are described in the article entitled Monitoring of transboundary water cooperation: Review of Sustainable Development Goal Indicator 6.5.2 methodology, recently published in the Journal of HydrologyThis work was conducted by Melissa McCracken from Oregon State University and Chloé Meyer from Paris Nanterre University.


  1. McCracken and Wolf. 2018. “Updating the Register of International River Basins of the World.” International Journal for Water Resources Development. Submitted for review.
  2. UN-Water, 2016a. Integrated Monitoring Guide for SDG 6: Targets and global indicators.
  3. IGRAC, UNESCO-IHP. 2015. Transboundary Aquifers of the World Map 2015. International Groundwater Resources Assessment Center.

About The Author

Melissa is a Transboundary Freshwater Dispute Database Manager and PhD Candidate at Oregon State University.

Chloe is a research scientist at the United Nations Educational, Scientific and Cultural Organization, International Hydrological Programme.