Henson, W.R. Culling, D.P. 20250115 groundwater model Reston, VA, USA U.S. Geological Survey U.S. Geological Survey model archive data release https://doi.org/10.5066/P13U6JPT Wesley R. Henson Randal T. Hanson Scott E. Boyce Joseph A. Hevesi Elizabeth Jachens 20250115 publication Reston, VA, USA U.S. Geological Survey The Salinas Valley Groundwater Basin in Monterey and San Luis Obispo Counties of California is a highly productive agricultural area, contributes significantly to the local economy, and provides a substantial portion of vegetables and other agricultural commodities to the Nation. Increases in agricultural development and population have put increasing demand on both surface water and groundwater resources in the valley. The added demand coupled with more extremes in climate variability has resulted in water management challenges in the Salinas Valley. These challenges are predominantly related to distribution of water supply throughout the basin, that is where and when the water is needed. To evaluate the water management issues in the Salinas Valley, the U.S. Geological Survey, Monterey County Water Resource Agency, and the Salinas Valley Basin Groundwater Sustainability Agency have developed a suite of models (geologic framework, watershed, historical, and operational models) that represent the Salinas Valley integrated hydrologic system. This data release includes both the integrated hydrologic model (referred to as the historical model) and a reservoir operations model (referred to as the operational model). The historical model uses historical climate, land use, stream flow diversions, and reservoir releases to simulate agricultural processes along with municipal and industrial water demands and reclaimed wastewater. The operational model adds an embedded reservoir operations framework to the simulation of historical conditions. The operational model uses specified operational rules to simulate reservoir releases and changes in reservoir storage. The operational model uses current reservoir operations and constant land use as opposed to the specified reservoir releases and changing land use types used in the historical model. The operational model is a hypothetical baseline model that can be used by local water managers to evaluate and quantify potential benefits of water supply projects. Together the suite of models, including the historical and operational model archived here, form a toolbox that can be used to simulate irrigated agriculture and associated reservoir operations of the integrated hydrologic system of the Salinas Valley. This data release archives the Salinas Valley Integrated Hydrologic Models (SVIHM), a historical and operational simulation with a common simulation horizon of 56 years from 1967-2022. The accompanying scientific investigations report, "Salinas Valley Integrated Hydrologic and Reservoir Operational Models, Monterey and San Luis Obispo Counties, California" documents the development of the model input and output files from 1967-2018. The calibration for the extended years from 2019-2022 is maintained from the documented calibration. The simulations archived in this data release collectively are used to evaluate the hydrology and hydrogeology of the groundwater system in the Salinas Valley, CA, and to analyze historical water availability with a primary focus on the primary water-producing subareas of Monterey County Water Resources Agency Zone 2c water management area and the Monterey County Salinas Valley groundwater sustainability basin management boundary. The model archive consists of two models, an historical and operational model, that share many common input files. Users are encouraged to review the model documentation and supplemental section of the accompanying report (Henson and others, 2025) to understand the purpose, construction, and limitations of the historical and operational models. The report output can be replicated by running the models as is described in more detail in the Salinas_readme.txt file that is part of this data release. The model will run successfully only if the original directory structure is correctly restored. The model archive is broken into several pieces to reduce the likelihood of download timeouts. Instructions for reconstructing the original directory structure and running the model included in this data release and described in the model documentation report can be found in the Salinas_readme.txt ASCII file which can be downloaded as part of this data release. We credit Monterey County Water Resource Agency in this data release summary because they collected all of the groundwater levels and contours and provided information about wells and time series for diversions, recycled water deliveries, and reservoir inflows and releases. All input data used in these models were published in separate data releases. 19671001 20220930 publication date Complete As needed -122.0467 -120.5364 36.9669 35.6304 ISO 19115 Topic Category geoscientificInformation inlandWaters environment USGS Thesaurus modeling groundwater flow hydrology None MODFLOW-OWHM Farm Process usgsgroundwatermodel USGS Metadata Identifier USGS:672ea698d34ea9e450893076 Geographic Names Information System California Salinas Valley Monterey County San Luis Obispo County None. Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from this data release. none. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. It is requested that the suggested citation for this USGS data release be included in any publications that reference or utilize these data. Wesley R. Henson U.S. Geological Survey mailing and physical

4165 Spruance Road, Suite 200

San Diego CA 92101 USA (619) 222-2243 whenson@usgs.gov Monterey County Water Resource Agency, Salinas, California None Unclassified None The model requires at least 500 MB of memory and was successfully run using MODFLOW-OWHM v2.3.0 (Boyce, 2020) on a 64-bit Windows 10 Enterprise OS. Donald Sweetkind 2023 dataset https://www.sciencebase.gov U.S. Geological Survey U.S. Geological Survey data release https://doi.org/10.5066/P9IL8VBD Wesley Henson Elizabeth R Jachens 2022 dataset https://www.sciencebase.gov U.S. Geological Survey U.S. Geological Survey data release https://doi.org/10.5066/P9850MAK Wesley Henson Joseph A Hevesi Randall T. Hanson Daniel Bittner Deidre M Herbert Elizabeth R Jachens 2022 dataset https://www.sciencebase.gov U.S. Geological Survey U.S. Geological Survey data release https://doi.org/10.5066/P93COXL6 Wesley Henson Joseph A Hevesi Randall T Hanson Michelle A Stern Elizabeth R Jachens 2022 dataset https://www.sciencebase.gov U.S. Geological Survey U.S. Geological Survey data release https://doi.org/10.5066/P9GTQCCF Joseph A Hevesi Wesley Henson Randall T Hanson Michelle A Stern Elizabeth R Jachens 2022 dataset https://www.sciencebase.gov U.S. Geological Survey U.S. Geological Survey data release https://doi.org/10.5066/P942J2BC Wesley Henson Scott E Boyce Howard Franklin Amy Woodrow Matthew N Baillie Elizabeth R Jachens 2022 dataset https://www.sciencebase.gov U.S. Geological Survey U.S. Geological Survey data release https://doi.org/10.5066/P9CWNHN3 Wesley Henson Marisa M Earll Sandra Bond Elizabeth R Jachens Amy Woodrow 2023 dataset https://www.sciencebase.gov U.S. Geological Survey U.S. Geological Survey data release https://doi.org/10.5066/P9U67MIQ Wesley R. Henson Randall T. Hanson Scott E Boyce Joseph A Hevesi Elizabeth R Jachens 2025 publication https://doi.org/10.3133/sir2025XXXX Scott E. Boyce Randall T. Hanson Ian Ferguson Wolfgang Schmid Wesley R. Henson Thomas Reimann Steffen W. Mehl Marisa M. Earll 2020 publication n/a US Geological Survey https://doi.org/10.3133/tm6A60 Scott E Boyce 2020 dataset https://www.sciencebase.gov U.S. Geological Survey U.S. Geological Survey software release https://doi.org/10.5066/p9p8i8gs Calibration of the SVIHM was accomplished using a combination of trial-and-error and computer-assisted process of minimizing differences between real-world observations and their simulated equivalent values. PEST HP (Doherty, 2024) was used for computer-assisted parameter estimation and sensitivity analysis. Bounds on model parameters were set to keep parameters within a realistic range of values. Initial parameter estimation was performed in a stepwise format that started with the landscape processes, followed by adjustment of hydraulic properties, streambed properties, multi-aquifer well properties, general-head boundary conductance, and fault conductance. Parameter adjustments were based on the comparison of observed values to their simulated equivalents. The simulated equivalent values were compared to all observed values and provided a measure of model performance through various historical time intervals and model analysis regions. The resulting error distributions constrain model parameters, and the comparison between simulated and observed values provided a basis for sensitivity analysis of selected parameters. The SVIHM was calibrated using 5,736 streamflow observations, 291 diversion observations, 2,508 streamflow difference observations, 2,011 quarterly mean streamflow observations, and 527 annual mean streamflow observations, 459 monthly groundwater-level observations and 50,992 drawdown observations, 11,942 quarterly mean groundwater-level observations and 11,942 drawdown observations, 5,415 annual mean groundwater-level observations and 5,415 annual mean drawdown observations, and 1,576 head difference observations, 3,630 monthly, 1,215 quarterly, and 315 annual agricultural observations. The number of adjustable parameters changed during parameter estimation. A total of 311 initial parameters were refined to about 40 parameters that were determined to be relatively sensitive and important and include aquifer conductivity, aquifer storage, climate scale factors, drain conductance, runoff, and stream conductance parameters. No formal logical accuracy tests were conducted Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record and the associated model documentation report (Henson and others, 2025) for additional details. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted John Doherty 2010 publication Published in Brisbane, Australia by Watermark Numerical Computer Inc. Accessed on 12/1/2024 https://pesthomepage.org/PEST.php Digital and/or Hardcopy 19671001 20220930 publication date PEST HP PEST HP is used to calibrate the model Monterey County Water Resources Agency 20241201 tabular digital data https://www.countyofmonterey.gov/government/government-links/water-resources-agency Digital and/or Hardcopy 19671001 20220930 See Supplemental Info Monterey County Water Resources Agency Processed and used as input to the historical and operational models. The process used to develop, calibrate, and apply the model is fully described in the model documentation report "Salinas Valley Integrated Hydrologic and Reservoir Operations Model, Monterey and San Luis Obispo Counties, California" (Henson and others, 2025). 2024 Raster Pixel NAD 1983 UTM Zone 10S 0.9996 -123.0 0.0 500000.0 0.0 row and column 530 530 survey feet SVIHM_Boundary.shp Attribute Table Table containing attribute information associated with the historical and operational model domains (identical). The shapefile that contains this data can be found in the georef.zip folder that is part of this model archive data release. Producer Defined FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Shape type. Id ID = 0 designates the inactive model domain; ID = 1 designates the active model domain. Producer Defined 0 1 An explanation of the top level compressed directories included in this model archive data release are included here: ancillary.zip - Contains ancillary files bin.zip - Contains the executable files used to run the historical and operational simulations (models) georef.zip - Contains a shapefile defining the active and inactive model areas model.zip - Contains all MF-OWHM input files for the historical and operational models output.zip - Contains selected output for the historical and operational models source.zip - Contains the source code for MF-OWHM used to run the models Henson, W., and Culling, D., 2025, Salinas Valley Integrated and Operational Hydrologic Models: U.S. Geological Survey data release https://doi.org/10.5066/P13U6JPT U.S. Geological Survey GS ScienceBase mailing

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov The data have been approved for release by the U.S. Geological Survey (USGS). Although the data have been subjected to rigorous review and are substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, the data are released on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from authorized or unauthorized use. Although the data, software, and related material have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Salinas_readme.txt none ASCII text file This ASCII text file describes the model data release. This file also includes instructions on how to run the model contained in this data release. .034 https://doi.org/10.5066/P13U6JPT None 20250410 Wesley Henson USGS - SOUTHWEST REGION Research Hydrologist mailing and physical

SD WRD Project Office,San Diego State University

San Diego CA 92101-0821 619-225-6170 whenson@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998