Engaging Stakeholders to Improve the Use of Groundwater Flow Models for Decision Making

Wisconsin regulatory agencies develop and use groundwater flow models for science-based decision support on often-controversial topics such as high-capacity well permitting, land-use changes, and high-profile projects such as mines and landfills. Most groundwater flow models operate at steady-state where model parameters and outputs such as pumping rates, groundwater recharge, stream baseflows, and groundwater levels remain constant with time. However, the problems groundwater flow models investigate are inherently transient. Many environmental variables are constantly changing over a variety of time scales ranging from very short (rainfall events, daily irrigation pumping) to very long (seasonality, climate change). Although most groundwater flow models can run in transient mode, model time steps always represent a compromise between the complex changing environment and the modeler’s need to simplify the problem to make it tractable. Uncertainty and simplification inherent in models are often held as the basis for public opposition and mistrust of model results. This project addresses the need to engage key stakeholders in the process of defining the spatial and temporal resolution of performance measures (i.e. minimum streamflows) and water management strategies (i.e. pumping rate adjustment) in order to justify model utility for public acceptance and effectively evaluate the ability of such strategies to meet selected performance measures under potential future land use and climate change scenarios.