The Basin Setting project began late in 2018 to develop portions of the Groundwater Sustainability Plan (GSP) in each of the three subbasins in Butte County: Vina, Butte, and Wyandotte Creek subbasins.  Our department has contracted with Davids Engineering to conduct the work on behalf of all Groundwater Sustainability Agencies in these subbasins.  The project is funded by the Prop 1 GSP planning grant. 

This PowerPoint provides an overview of the project scope.

The “Basin Setting” portion of the GSP describes characteristics of the subbasin that both change and do not change over time.  Characteristics like the geology, structure and physical characteristics of the aquifer systems, and how water moves in and through the system (such as recharge and pumping areas) generally do not change over time.  This understanding of the basin’s physical characteristics is called the Hydrogeologic Conceptual Model.  This becomes the basis for our understanding groundwater behavior and cause and effect relationships in the groundwater system.  Additional sub-sections of the Basin Setting describe characteristics of the subbasin that do change over time and will likely change in the future, such as changes in climate (affecting water supplies), land use, water demands, etc.  This includes a description of Groundwater Conditions (groundwater levels, water quality conditions, and subsidence if present) and the Water Budget.  The Water Budget is our accounting (quantitative) of the inflows and outflows of water through the surface water and groundwater systems.  Information in the Basin Setting portion of the GSP as well as the description of the Monitoring Network will support and frame future and complex discussions that will occur to define Undesirable Results and thresholds for the successful management of the subbasins through Projects and Actions.

We expect draft results to be presented and discussed in each of the subbasins at public advisory committee meetings or public workshops this coming March and/or April.  A high level overview of the results will be presented to the Water Commission, likely at their April 1^st meeting.  A table summarizing meeting dates, times, locations, and content will be posted here in February.  Stay tuned!