Navigating the complexities of global and local water resources challenges requires collaboration and mutual learning among diverse knowledge systems and disciplines. However, Western philosophical approaches to generating knowledge have prevailed in water management and hydrology, often overlooking community priorities, practices and perspectives, and power asymmetries - including gender inequalities, racism, and colonial injustices. In this perspective paper, we explore the co-creation of water knowledge (CCWK) concept to value multiple and diverse forms of knowledge. We identify four overarching principles (inclusivity, openness, legitimacy, and actionability), highlighting the importance of establishing relationships and collaborative leadership, adopting key tools and techniques, and integrating knowledge for water resources management. Furthermore, we argue that prioritizing epistemic justice is essential for effective CCWK. To address these, we advocate for more interdisciplinary and reflexive research practices that challenge and disrupt Western scientific traditions shaped by functionalist and colonial legacies.

Sand dams are impermeable water harvesting structures built to collect and store water within the volume of sediments transported by ephemeral rivers. The artificial sandy aquifer created by the sand dam reduces evaporation losses relative to surface water storage in traditional dams. Recent years have seen a renaissance of studies on sand dams as an effective water scarcity adaptation strategy for drylands. However, many aspects of their functioning and effectiveness are still unclear. Literature reviews have pointed to a range of research gaps that need further scientific attention, such as river corridors and network dynamics, watershed-scale impacts, and interaction with social dynamics. However, the scattered and partially incomplete information across the different reviews would benefit from an integrated framework for directing future research efforts. This paper is a collaborative effort of different research groups active on sand dams and stems from the need to channel future research efforts on this topic in a thorough and coherent way. We synthesize the pivotal research gaps of a) unclear definition of “functioning” sand dams, b) lack of methodologies for watershed-scale analysis, c) neglect of social aspects in sand dam research, and d) underreported impacts of sand dams. We then propose framing future research to better target the synthesized gaps, including using the social-ecological systems framework to better capture the interconnected social and biophysical research gaps on sand dams, fully utilizing the potential of remote sensing in large-scale studies and collecting sand dam cases across the world to create an extensive database to advance evidence-based research on sand dams.