However, this may be easier said than done. Climate scientists may provide thousands of scenario about possible future climates that lead to wide ranges of future hydrologic conditions. For example,climate projections used in the International Upper Great Lakes Study to recommend lake regulationprotocols between the US and Canada showed that lake levels—a key planning parameter—could go either higher or lower in the future. Further complicating this uncertainty are demographic and landuse changes, as well as active stakeholder groups advocating for their interests under potentially water-insecure conditions. Water planners and managers need guidance that helps them move away from what we do not know about the future to what we do know. In other words, it may not be known what future flow will result from a 100-year return period storm event, but it may be easier to estimate the annual expected damages that will likely be unacceptable in 2050. Is this a possible paradigm shift that can help decision making under deep uncertainty?