SGMA Climate Change Desktop tools for IWFM and Modflow Craig Cooledge Water Resources Engineer Jacobs Engineering CWEMF Annual Meeting April 23rd 2019

Introduction

DWR-Provided Information DWR Climate Change Analysis Background WSIP Datasets: https://data.cnra.ca.gov/dataset/climate-change-projections-wsip-2030-2070

Development of Projected Water Budgets 23 CCR §354.18 (e) Each Plan shall rely on the best available information and best available science to quantify the water budget for the basin in order to provide an understanding of historical and projected hydrology, water demand, water supply, land use, population, climate change, sea level rise, groundwater and surface water interaction, and subsurface groundwater flow.

Climate Data and Tools VIC gridded change factors for precipitation and reference evapotranspiration Monthly timeseries dataset from 1915 – 2011 Desktop tools for IWFM and MODFLOW based models to facilitate processing of climate data provided by DWR

Data available on SGMA Data Viewer https://sgma.water.ca.gov/webgis/?appid=SGMADataViewer

Methodology

Projected Water Budget Development with a Numerical Model

IWFM and MODFLOW Desktop Tools – Climate Change Data Processing ArcGIS Toolbox based tools Relates VIC grid to MODFLOW Grid/IWFM elements, small watersheds, or other regions Project historic data under future climate scenarios Produces MODFLOW/IWFM input files for climate change scenario simulations

Tool Showcase

Tool #1: Establish working directory and input data for IWFM model IWFM Tool Tools are executed in ArcCatalog or ArcMap Documentation provided with tool describing input requirements and tool execution Tool #1: Establish working directory and input data for IWFM model Tool #2: Relate IWFM Model to VIC Model and Perturb Historic Input Data

Tool #2 IWFM Tool Snapshots Tool #1

IWFM Input Data Development Considerations ET data can be aggregated spatially and temporally Compute time-varying ET based on based on repeating pattern of input data (IWFM 4000 Flag) May require additional GIS attributes or lookup tables to relate data spatially Projected Small Watersheds Data Single dataset can be processed for elements and small watersheds

Tool #1: Establish working directory and input data for MODFLOW model MODFLOW Tool Tools are executed in ArcCatalog or ArcMap Documentation provided with tool describing input requirements and tool execution Tool #1: Establish working directory and input data for MODFLOW model Tool #2: Relate MODFLOW Model to VIC Model and Perturb Historic Input Data

MODFLOW Tool Snapshots

MODFLOW Input Data Development Considerations Model Arrays Require Specific File Naming Convention Tool determines Month and Year based on filename Model Array File Delimiter Tool will decipher the delimiter that is used (space, comma, etc.) Needs to be consistent throughout all files Should be consistent with MODFLOW friendly formats

Additional desktop tools

Streamflow Change Factor Correction Tool Spreadsheet tool to assist in perturbing basin unimpaired streamflow under climate conditions 2nd order correction calculation to ensure monthly timing and annual pattern of streamflow hydrograph is consistent with climate change simulations

CalSim II to C2VSim Diversion Lookup Effort to map CalSim II Diversions to C2VSim Diversions Incorporate changes in deliveries based on CVP/SWP system operations under projected hydrology Released in the near future

Other Related DWR Modeling Tools DWR SGMA Resources SGMA Data and Tools: https://water.ca.gov/Programs/Groundwater-Management/Data-and-Tools SGMA Climate Change Resources: https://data.cnra.ca.gov/dataset/sgma-climate-change-resources Climate Change Documentation: https://water.ca.gov/Programs/Groundwater-Management/SGMA-Groundwater-Management/Best-Management-Practices-and-Guidance-Documents Other Related DWR Modeling Tools IWFM: https://water.ca.gov/Library/Modeling-and-Analysis/Modeling-Platforms/Integrated-Water-Flow-Model C2VSim: https://water.ca.gov/Library/Modeling-and-Analysis/Central-Valley-models-and-tools/C2VSim SVSIM: https://water.ca.gov/Library/Modeling-and-Analysis/Central-Valley-models-and-tools/SVSim

Thank you! Craig Cooledge Craig.Cooledge@Jacobs.com Water Resources Engineer Jacobs Engineering Tyler Hatch, PhD, PE Tyler.Hatch@water.ca.gov Senior Engineer, Water Resources Sustainable Groundwater Management Program

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