Colorado River Basin Climate and Hydrology State of the Science

The Colorado River Basin currently faces unprecedented stresses. Persistent dry conditions since 2000, along with the increasing recognition that warming temperatures are impacting the hydrology of the basin, have led to great concerns about the long-term reliability of basin water supplies. With ever-higher stakes for water resource planning and decision making, an even greater emphasis is placed on the tools that support those activities, notably Reclamation’s operations and planning models and similar models used at other agencies. The usefulness of these system models depends on many types of datasets and forecasts that serve as inputs to them, as well as the research and scientific understanding underpinning this complex chain of data and models. The development and refinement of the different links of the chain necessarily involves researchers, forecasters, and water managers.

New research efforts have advanced our understanding of the hydroclimate of the basin and how key hydroclimate processes, variability, and changes can be captured in data and models. This rapid expansion of the scientific knowledge base, and the increasing complexity of the data and models used to operationalize that knowledge, parallel the growing uncertainties about the future climate and hydrology. Accordingly, basin stakeholders have recognized the importance of reassessing the scientific and technical basis for management and planning.