Understanding the changes in the distribution and quantity of, and demand for, water resources in response to a changing climate is essential to planning for, and adapting to, future climatic conditions. In order to plan for future conditions and challenges, it is crucial that managers understand the limitations and uncertainties associated with the characterization of these changes when making management decisions. Changes in consumptive water use (water removed without return to a water resources system) will change streamflow, impacting downstream water users, their livelihoods, as well as aquatic ecosystems. Historical changes in available water may be attributed to changes in precipitation; but these changes may also be attributable to changes in consumptive use. Understanding the roles of natural and anthropogenic influences on the water cycle is an important component of this project. The objective of this project was to provide an automated methodology and data products that the public can view, work with, and download through ScienceBase to assess: the accuracy of available climate data and climate projections, the hydrologic effects of these drivers on runoff for historical and future conditions, and the role of consumptive water use on available water supply.