WRRC Director Sharon B. Megdal's opinion paper, “Increasing the visibility of transboundary groundwater,” was published on March 21 in PLOS Water. In her introduction, Megdal references the 2022 United Nations World Water Development Report, Groundwater: Making the invisible visible, noting that unlike lakes, rivers, and other surface waters, groundwater is easy to overlook and transboundary aquifers, which cross jurisdictional borders, “can be particularly challenging” to characterize. Using US-Mexico transboundary aquifer assessment and management as an example, Megdal explores the successes and challenges of binational cooperation. She observes that “A critical condition for groundwater management in the transboundary setting is a functioning mechanism for cooperation, one that is built upon trust and mutual respect.” Megdal concludes by stating, “Reliance on groundwater is increasing. Careful management of this vital but invisible resource is essential to the water security of regions throughout the world. The work can be particularly challenging in transboundary settings, but water professionals must lead the way so that communities can benefit from their efforts to make the invisible visible.” The article is open access and available to read at the link below.