invisible water, no treaty

Problem statement

Groundwater is the largest store of fresh water most countries have, and 468 known aquifers underlie two or more countries. Yet the UN's mid-term assessment of SDG indicator 6.5.2 (share of transboundary basin area covered by an "operational" cooperation arrangement — one with a joint body, at least annual meetings and information exchange, and joint management plans) reports that "24 countries report having a total of 13 aquifer-specific arrangements — this figure includes five arrangements that do not meet the SDG indicator 6.5.2 operationality criteria," and that "48 countries have less than 10 per cent of their aquifer area covered." The global average of the aquifer component is 46 percent, but the report is explicit that the improvement since 2020 mainly reflects countries counting aquifers under river-basin arrangements and simplifying aquifer delineation, not new groundwater cooperation: "the changes in indicator values mainly reflect an effort by countries to update their data rather than showing progress in the adoption of new arrangements." The unsolved problem is that the institutional machinery of transboundary water cooperation was built for rivers — visible, measurable, with a century of treaty practice — and does not fit an "invisible resource" that "demands close cooperation between countries from the outset to assess their extent and transboundary dynamics."

Why this matters

The report counts 153 UN Member States as reliant on waters that flow from or to another country; the shared aquifers among them supply drinking water and irrigation in exactly the arid and semi-arid regions — North Africa, the Sahel, the Middle East, Central Asia, the Americas' drylands — where surface water is scarce and climate change is making groundwater the adaptation resource of last resort. Unmanaged shared aquifers are depleted, salinized, or polluted by whichever side pumps hardest, and because the damage is underground it is discovered late and is often irreversible. SDG target 6.5 calls for all transboundary waters to be covered by operational arrangements by 2030; on the report's own projection, "barely more than a third of countries sharing transboundary rivers, lakes and aquifers would have 90 per cent or more" of their basin area covered by then, and aquifers are the laggard component.

What’s been tried and why it hasn’t worked

The legal and scientific groundwork exists: UNESCO's ISARM initiative and IGRAC have inventoried shared aquifers for more than 15 years (366 known in 2015, 468 on IGRAC's 2021 map), the 2008 ILC Draft Articles on the Law of Transboundary Aquifers and the two global water conventions "provide a sound basis," and the GEF Transboundary Waters Assessment Programme (TWAP, 2016) reportedly characterized 199 shared aquifers (figure from TWAP, not from the 2024 report). The arrangements that do exist — the North-Western Sahara Aquifer System consultation mechanism (2002), the Nubian Sandstone joint authority (1991), the Franco-Swiss Genevois aquifer convention (2007), the Stampriet mechanism nested in the Orange-Senqu commission (2017), the Senegalo-Mauritanian aquifer declaration (2021) — show it can be done. But the report's Table 3 shows the Guarani Aquifer Agreement (2010), the Iullemeden/Taoudeni consultation mechanism (2014), the U.S.–Mexico Transboundary Aquifer Assessment Program (2009), and the Abbotsford-Sumas task force (1992) as "not operational": signed or formed, then never given a functioning joint body, regular meetings, or joint plans. Three obstacles recur in the report's own language: countries lack the data even to delineate their shared aquifers ("many countries have no data or limited cooperation on their transboundary aquifers"); river-basin organizations are the default institutional home, but the report finds effective aquifer cooperation only "within some river and lake basin arrangements" that have created groundwater task forces or working groups, and many lack a groundwater mandate; and "if work on aquifers has not been initiated, some countries have proven reluctant to include aquifers in their SDG indicator 6.5.2 calculation, even where they might fall within the scope of a river basin arrangement" — political reluctance to acknowledge a shared resource before its extent is known. The result is a chicken-and-egg problem: no joint assessment without an arrangement, no arrangement without a joint assessment.

What would unlock progress

Progress needs a lighter first rung on the cooperation ladder than a treaty: standardized, low-cost joint-assessment protocols (shared monitoring wells, harmonized data formats, agreed delineation methods) that two countries can adopt without conceding legal positions, plus templates for adding a groundwater working group to an existing river-basin organization — the Stampriet-in-Orange-Senqu model. The report itself credits the SDG 6.5.2 reporting process with "focus[ing] greater attention on aquifers" and the flexibility to use IGRAC's Global Groundwater Information System for approximate delineation "without the need for costly and in-depth studies" — evidence that lowering the technical entry cost moves countries. Adjacent precedents: fisheries and air-quality regimes that began with joint monitoring bodies long before allocation rules; and the Genevois aquifer, managed for decades at the sub-national level by a Swiss canton and French communes rather than by national ministries.

Entry points for student teams

A team could take one of the ~450 shared aquifers with no arrangement (or one of the five "not operational" ones) and produce a design proposal for the minimum viable cooperation mechanism — what data each side already holds, what a shared monitoring protocol would cost, which existing basin organization could host a groundwater working group, and what the ILC Draft Articles require. A data-science team could build the comparative dataset the report lacks: for all 468 aquifers, which have arrangements, which are operational, and what distinguishes them (number of countries, existing river-basin body, aridity, data availability), as a research contribution. A hydrogeology/GIS team could prototype a delineation-and-data-sharing template using IGRAC's public GGIS layers for one aquifer pair. Relevant skills: international water law, hydrogeology, institutional design, GIS and data analysis.