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3.3 System Modeling/Linear Asset Capacity Assessment 3.3.1 Model Coordination Workshop (4 hours, in-person) CONSULTANT will facilitate a four-hour in-person coordination meeting with the COUNTY's existing hydraulic modeling consultant in order to discuss existing model infrastructure, data sources, calibration efforts and workflows, data and calibration needs, and other topics prior to model review and calibration. 3.3.2 Model Review and Existing Conditions Updates CONSULTANT will update COUNTY's most current hydraulic models (three total; one for distribution system, one for wastewater collection system, and one for reuse system) to assess current and future system performance. CONSULTANT will leverage COUNTY's current Geographic Information Systems (GIS) attributes for updating the existing conditions hydraulic models. CONSULTANT will run the existing conditions models with average flow and pressure conditions to check the reasonableness of the resulting modeled system pressures for distribution, collection, and reuse systems. Scope assumes that GIS is up-to-date and no updates to GIS are included. 3.3.3 Existing Conditions Model Validation CONSULTANT will work with the COUNTY to identify two conditions at which to run each of the three models. For the collection system model, these will be a typical dry weather condition and a wet weather condition. For the potable and reuse distribution system models, these conditions will represent a period of baseline demand and a period of high demand. CONSULTANT will utilize readily available data from representative periods for each system to run initial model scenarios for the COUNTY's three hydraulic models. This includes comparing results from the from the three hydraulic models to actual and typical system performance criteria including minimum and maximum pressure, velocity, fire flow(for potable water system), and headloss. Models will be considered valid if 90% of the model results are within 10% of actual flow data, within 10% of actual or expected pressure/level data, or within 5 feet of actual or expected water column as applicable and aligned with actual SSOs (for collection). CONSULTANT will present the six model outcomes to the COUNTY and discuss the path forward for each model to perform boundary level calibration with additional - • available data as part of Task 3.3.3 below, or to perform field data collection and full calibration as part of Task 3.3.4 below. 3.3.4 Boundary Level Calibration CONSULTANT will calibrate models as needed to known boundary level field conditions (i.e. known system pressures, pump station discharge pressures, pressure zone HGLs, measured flows). The boundary level calibration will be considered complete when 90% of the model results are within 10% for the flow data and 5 feet of water column of the field data. All exceptions will be justified and documented. Time series data validation will be considered compared when the model is able to replicate the observed trends and minimum and maximum points. Individual time points in time series will not be compared. CONSULTANT will meet with COUNTY operations staff to review model results and prepare for field calibration efforts if further model calibration is warranted. 3.3.5 Field Data Collection for Full Calibration 6 306