Even the knowledge that information is missing can inform decisionmaking processes. Transboundary water management has many special problems not always found at smaller scales, particularly with the transmission, alignment, resolution and integration of information. For instance, collected data should be stored in a way that will allow easy retrieval, which may entail specific agreements in a transboundary setting. Climate change adaptation also has special concerns, given that clear, tangible, precise and accurate information may be available for the past, while knowledge about the future lacks all of those qualities. All basins, countries and water management decisions have at least some gaps in information, particularly under holistic approaches that include hydrological, environmental and socioeconomic data. Instead of trying to describe perfect data, this chapter will focus on assessing, gathering, compiling and exchanging "good enough'information to enable effective transboundary climate change adaptation decisions.