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MEMORANDUM <br />Rice Creek Commons Water Distribution System Modeling Results Update <br />January, 2025 <br />Page 3 <br />H:\KIMLEYHO_PR\0T4133552000\2_Preliminary\C_Reports\Preliminary Design Report Update\Report Update\Water Preliminary Engineering Analysis\Memo-Rice Creek Commons Water <br />Distrib Sys Modeling Results Update Final Draft 01.24.2025.docx <br />determined that the average day demand anticipated for TCAAP would add, approximately, an <br />additional 0.75 MG per day to the water system. Using the same multiplier factors, the maximum day <br />demand anticipated for the TCAAP development is 2.25 MG per day, with 4.5 MG per day for a peak <br />hour demand. <br />The next step in model development was to determine the accuracy of the model compared to the <br />actual system. A model analysis was performed to replicate the existing system. Using the results of <br />this analysis, modeled pressures were compared to pressures from field collections obtained from <br />provided data. The references used for pressure comparisons were from multiple hydrant tests <br />performed at various locations throughout the City and from the Water System Master Plan prepared <br />for the City of Arden Hills by Maier Stewart and Associates, Inc., 1990. No new field data was collected <br />during the development of this model. <br />Comparison of Model to Available Data <br />The updated model was compared to hydrant test data from the Water Distribution System Hydraulic <br />Model Calibration and System Evaluation Report by AE2S in December 2019. Twelve of the hydrant tests <br />from the 2019 report were checked with the updated model. No new field data was collected during this <br />analysis and report update. <br />Comparing model results to the field data presented in the 2019 Water Distribution System Hydraulic <br />Model Calibration and System Evaluation Report , indicates that the updated water model had similar <br />calibration results and is a reasonable representation of the distribution system. The model results and <br />field data were compared by their respective static pressures and residual pressures. Model data was <br />analyzed at model nodes representing the hydrant locations of the field data. Table 1 summarizes the <br />comparison results of the updated model. Updated model results differed slightly from the 2019 <br />evaluation’s results due to the recent improvements that were implemented into the model, and <br />because the exact tower water levels and booster station pumping rates during each hydrant test are <br />unknown for this update analysis and calibration. Test no. 6 and no. 21 had residual pressure <br />differences between the model and field data above desired tolerance levels, this difference was also <br />noted in the 2019 report for the same hydrant tests and was attributed to isolations valves being closed <br />or partially closed during the tests.