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Second Submittal <br /> 4.0 MODEL CALIBRATION <br /> Calibration is the process by which model parameters are adjusted within the range of <br /> measured/known values until a set of"targets" is matched. For a groundwater model, <br /> targets are drainage discharge rates, increases or losses to surface water features,but most <br /> commonly groundwater elevations measured in wells. <br /> 4.1 Calibration Targets <br /> For this modeling effort, the calibration targets are the spring and early summer <br /> groundwater elevation measurements from the Site monitoring wells and from the <br /> neighbor's wells. Altbough the neighbor's wells were not professionally surveyed like Site <br /> monitoring wells, equal credibility was given to every well to evaluate model calibration. <br /> 4.2 Calibration Results <br /> The model was set up in a step-wise fashion, adding boundaries (ditches, drains, ponds) <br /> one model-run at'a time until;the model was built. Once the model was running, <br /> adjustments were made to boundary conditions within ranges as defined previously that <br /> represented the early irrigation season (May-July). This time period was chosen as <br /> representative of the first round of groundwater elevations measurements. The adjustments <br /> to boundary conditions were made until the model represented the distribution of measured <br /> groundwater elevations in the monitoring and neighborhood wells. Hydraulic conductivity <br /> and porosity were set as defined by the CDSS (CDWR, 2017) database in order to provide <br /> consistency with LRM's substitute water supply plan submitted to the DWR. <br /> Simulated groundwater elevations from the model cells representing wells on the date <br /> measurements were compared against measured elevations as shown in Figure 11. Also, <br /> shown in Figure 11 are results of regression analyses (coefficient of determination-r2, <br /> regression line slope and intercept) and the sum of the difference squared between <br /> simulated and measured groundwater elevations indicating the capacity of the model to <br /> accurately simulate groundwater levels in the wells. Figure 12 is a contour plot of the <br /> simulated groundwater elevations representative of the early irrigation season. <br /> Loveland Ready-Mix Concrete 15 Telesto Solutions,Inc. <br /> 20180112 gr [wmmmay_zwlsabmttal d— January 2018 <br />