As workers and activists involved in cross-border water conservation attempt to re-map lines of cooperation along the boundaries of watersheds, rather than political borders, they encounter what Paul Silverstein has referred to in other activist contexts as "scalar dilemmas." These water workers must operate simultaneously along local and international priorities, melding these different scales within their work. Along the Jordanian, Israeli, and Palestinian border regions that frame the Jordan River and several shared aquifers, the dilemmas of simultaneously engaging these different scales are particularly troublesome. This paper is based on multi-sited fieldwork with a tri-national environmental NGO and case-study communities on the Israeli and Jordanian sides of the Jordan River Valley. NGO workers engaged in community level projects attempt to prove their commitment to local residents through small-scale projects like building storage tanks and school water gardens, while also striving to scale up residents' notions of water problems and solutions to include international treaties and river restoration projects. At the same time, the NGO must prove to donor agencies that it successfully "articulates knowledge" as Timothy Choy has described the process of demonstrating both universal knowledge and locally appropriate know-how. Meanwhile, the waterworlds (the webs of social and environmental connections that water has in different societies) into which these cross-border projects intervene are not static, but rather historically fluid. In Jordan, water provisioning by the central government has extended only slowly and partially to peripheral regions of the Kingdom, and many periphery residents view it as arbitrary and unreliable. In the case study community, these problems are compounded by confrontations between farmers and family-owned spa businesses over how best to use the village's spring water. In Israel, in contrast, national control of water and the provisioning of even the most remote kibbutz was a central mission and mode of territorial control since the state's founding. Today, residents of the Israeli case-study community are adjusting to privatization of water, shifting regulations regarding water recycling, and the rise of large-scale desalination. This paper examines how NGO water workers attempt to re-map water rights and responsibilities, joining two very different waterworlds under a single watershed of shared stewardship, and how this re-mapping project requires situational re-scaling to manage the challenges of a politically fraught region. These encounters illuminate Israeli-Jordanian power relations, as well as how border area residents live out these regional politics in their everyday lives.