State of Calibration for California Central Valley Groundwater-Surface Water Simulation Model (C2VSim) CWEMF 2019 Annual Meeting Folsom, CA Presenter: Mesut Cayar April 23, 2019

Calibration Process Model Input Data QA/QC & Update Sensitivity Analysis - Water Demand & Supply - Soil Parameters - Aquifer Parameters - Stream Parameters - Storage Coefficients (Subsidence) IWFM Demand Calculator (IDC) Calibration - Land Use - Rootzone Budget Water Budget Update & Refinement - Water Use & Supply Budget - Groundwater Budget Groundwater & Surface Water Calibration - GW Heads Distribution - GW Levels & Trends - Streamflow - Stream Aquifer Interaction - Subsidence

Focus Area for Calibration Update Map Hydrologic Regions Sacramento River San Joaquin River Excluding Delta (Subregion 9)

Calibration Activities Since Beta Release Model Input Data QA/QC & Update Verified and corrected stream inflow Refined urban demand data Updated ET and precipitation data Updated soil parameters and ET for small watersheds Refined land use data based on local models Updated initial groundwater levels (above and below Corcoran) in San Joaquin and Tulare Basins Fixed various data bugs

Calibration Activities Since Beta Release Water Budget Update & Refinement Reviewed and mapped available local model data to C2VSim Adjusted water demand and supply data as-necessary Refined IDC calibration Soil parameter adjustments ET updates Refinement of reuse and return flows based on available data Refinement of rice operations Reviewed and assessed water demand and supply data at monthly level Re-configured surface water delivery areas Verified/updated surface water deliveries based on available Local/State/Federal data Turned off pumping for elements that are known to not pump historically Re-distributed pumping between above and below Corcoran Clay based on available data

Turlock Sub-Basin (Subregion 12) Review and map available local model data to C2VSim Reviewed and mapped available local model data to C2VSim

Butte, Wyandotte Creek, & Yuba Sub-Basins (Subregion 5) Adjusted water demand and supply data as-necessary Non-Ponded Ag. Supply Requirement Non-Ponded SW Supply Non-Ponded GW Pumping Ponded Ag. Supply Requirement Adjusted water demand and supply data as-necessary Refined of IDC calibration Soil parameter adjustments ET updates Refinement of reuse and return flows based on available data Refinement of rice operations Reviewed and assessed water demand and supply data at monthly level Re-configured surface water delivery areas Verified/updated surface water deliveries based on available Local/State/Federal Data Ponded SW Supply Ponded GW Pumping

Colusa Sub-Basin (Subregion 3) Adjusted water demand and supply data as-necessary Re-configured surface water delivery areas Verified/updated surface water deliveries based on available Local/State/Federal Data

Delta Mendota Sub-Basin (Subregion 10) Adjusted water demand and supply data as-necessary

Calibration Activities Since Beta Release GW Level Calibration & Sensitivity Analysis Adjusted small watershed parameters for baseflow and sw contributions Reviewed and assessed sensitivity of gw levels against water budgets, small watershed contributions and aquifer parameters Aquifer parameters pre-calibration analysis Horizontal and vertical hydraulic conductivity Storage coefficients Reviewed and assessed groundwater budgets

Overall Status of Groundwater Conditions & Calibration

Selected Groundwater Level Hydrographs Faults

Selected Groundwater Level Hydrographs Vertical K

Selected Groundwater Level Hydrographs Rice Fields

Selected Groundwater Level Hydrographs Missing SW supply

Selected Groundwater Level Hydrographs Drop down in sw supplies. SW deliveries are verified so should look into rice et, return flow and deep perc

Selected Groundwater Level Hydrographs Cosumnes area with little info

Selected Groundwater Level Hydrographs Turlock data mapped from local updates, good representation. Modesto has not been yet and the calibration is not as good yet

Selected Groundwater Level Hydrographs Merced is generally good, we had good local data shared with us Madera in general good. In the middle around Chowchilla area, the simulated values are higher and we could not be able to verify sw supply data before 1990s

Selected Groundwater Level Hydrographs North gw levels are high compared to simulated Other areas are mix K for Corcoran Clay needs to be refined Demand data needs to be updated Impacting neighbor subregions

Groundwater Budget – Sacramento River Hydrologic Region Replace this with the budget for Sacramento Valley (Subregions 1-7)

Groundwater Budget – San Joaquin River Hydrologic Region Replace this with the budget for Sacramento Valley (Subregions 1-7)

Next Steps Supply-Demand Corrections as Necessary Refinement of Hydraulic Conductivity for Corcoran Clay Evaluation of Streamflows & Stream Aquifer Interactions Evaluation of Subsidence Development of Guidelines for Automated Calibration Automated Calibration Documentation

Questions ?