Appendix I: Update on Land Subsidence in California

Update on Land Subsidence in California builds on Land Subsidence from Groundwater Use in California (Borchers et al., 2014), originally prepared for the California Water Foundation, by incorporating more than a decade of additional data, advances in monitoring and analytical tools, an updated summary of land subsidence impacts, and the regulatory framework established under SGMA. This report also supplements DWR’s Land Subsidence Best Management Practices (BMP) by further elaborating on recommended monitoring, analysis, and modeling approaches to evaluate land subsidence processes and management actions. This report includes data compilations and one-dimensional land subsidence modeling simulations for 50 long-term monitoring sites throughout the Central Valley. The modeling files and DWR’s land subsidence datasets are available on the California Natural Resources Agency Open Data Platform at https://data.cnra.ca.gov/. Additional resources on land subsidence are available on DWR’s website at https://water.ca.gov/Programs/Groundwater-Management/Subsidence/. This report was prepared for DWR by INTERA and James Borchers.