View File - Development Services - City of Oxnard

WATER RESOURCES TECHNICAL REPORT• Aquifer properties and aquifer boundary conditions were remapped onto the revisedgrid.• The stream package was modified, which involved significant modifications to adjustfor grid refinement and more accurately defining the Santa Clara River channeltopography.5.2.2 Update of Model CalibrationUpdate of the model calibration included the following activities:• Extending the calibration period from 1994 through 2000. This included incorporatingupdated pumpage, stream flow, effluent flow, artificial recharge, and mountain frontrecharge data over this period.• Recalibrating the model by comparing simulated groundwater levels from 1994 to 2000to actual groundwater levels from 1994 to 2000.The following adjustments were made to improve the model calibration in the PleasantValley Basin:• The locations of the Saticoy spreading ground, El Rio spreading grounds, and theSanta Clara River were more accurately located using the revised grid cells.• The 1993 starting head file created by the USGS for forward modeling was modifiedwith the use of kriging to more accurately match actual fall 1993 groundwater elevationdata.• A two-cell-wide zone of low hydraulic conductivity was added to the LAS from theCamarillo Hills to Port Hueneme to allow simulation of the presence of a fault, or someother low permeability structural or stratigraphic feature that creates the tightly spacedgrouping of groundwater elevation contours in this area.• The hydraulic conductivity in the LAS of the Pleasant Valley Basin was lowered.The following additional adjustments were made to improve the model calibration in otherareas of the model:• Leakage was decreased between the UAS and LAS in the West Las Posas Basin.• Conductance was decreased along the Las Posas fault, which separates the WestLas Posas Basin from the East Las Posas Basin.• Conductance was increased along the fault separating the Mount Basin from theSanta Paula Basin.• Leakage was increased between layers 1 and 2 in the Fillmore basin.5.2.3 Simulation of Water Management ScenariosWater management scenarios were simulated using the refined and updated groundwaterflow model to assess the long-range effects on groundwater levels from reducing theW112003002SCO LW1458.DOC/ 033390002 70