The Hydrology Division of the Arizona Department of Water Resources has been in the process over the last two years of updating the geology used in the Department’s Salt River Valley Regional Groundwater Flow Model. The geology update is the first phase of an overall plan to update the model’s geologic structure, numerical grid and extend the model’s steady-state and transient calibration periods. Releasing the provisional geologic report at this time allows us to provide the new data and analysis to water providers and other model users prior to the completion of the overall model update. Please be advised that the geologic data and interpretations that are included in this report and accompanying database are provisional at this time and subject to revision.

As a result of high growth rates, physically and legally limited water supplies, drought, economic constraints, and relatively little comprehensive water resource planning and management, water supplies are stressed in some parts of Arizona. The Arizona Department of Water Resources has collected and synthesized currently available water-related information for the State of Arizona into a “water atlas,” organized by planning area.