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MEMORANDUM <br />Rice Creek Commons Water Distribution System Modeling Results Update <br />January, 2025 <br />Page 11 <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 />Infrastructure Phasing <br />Phasing of the proposed tower construction is based on recommended water storage turnover rates, as <br />shown in Table 2. Based on cumulative demand of the north pressure zone with each phase of the <br />TCAAP/RCC site suggests that the proposed water tower be constructed by the time Phase 1 of RCC <br />development as shown in Appendix B is fully occupied. Once the demands for Phase 1 are added to the <br />existing system, the north pressure zone no longer has sufficient storage to meet ADD of the north <br />pressure zone. For the tower to be constructed by the time Phase 1 development is occupied, Bolton & <br />Menk recommends that design of the tower commences upon the City executing a RCC development <br />agreement with a developer. This will allow for adequate time to complete the tower project while <br />development is occurring and completed by the time phase 1 development is occupied. Appendix B <br />displays how demands for the TCAAP/ RCC area were developed. <br />Table 2 – Proposed Water Tower Construction Phasing <br />North Pressure Zone <br />Phase <br />Phase <br />Demand <br />(MGD) <br />Cumulative <br />Demand <br />(MGD) <br />Existing Storage Only Proposed Total Storage <br />Existing <br />Storage <br />Volume (MG) <br />Turnover Rate <br />with Existing <br />Storage (days) <br />Total Storage <br />Volume <br />(MG) <br />Turnover Rate <br />with Total <br />Storage (days) <br />Existing <br />System 0.445 0.445 0.5 1.1 0.5 1.1 <br />Phase 0(3)0.036 0.481 0.5 1.0 0.5 1.0 <br />Phase 1 0.131 0.612 0.5 0.8 (1)1.25 (2)2.0 <br />Phase 2 0.184 0.796 0.5 0.6 (1)1.25 1.6 <br />Phase 3 0.109 0.905 0.5 0.6 (1)1.25 1.4 <br />Phase 4 0.075 0.980 0.5 0.5 (1)1.25 1.3 <br />Phase 5(4)0.030 1.010 0.5 0.5 (1)1.25 1.2 <br />(1) Turnover rate is less than one day, signifying insufficient storage for average daily demands. <br />(2)Proposed construction of a 0.75 MG TCAAP tower prior to full occupancy of Phase 1 development. <br />(3) Phase 0 represents Thumb Parcel development demands. <br />(4) Tower size allows for some Arden Hills background growth and additional TCAAP development <br />intensification beyond 2024 development plan in Appendix B <br />It is recommended that the proposed west booster station be constructed at the same time as the Spine <br />Road project, therefore design should occur simultaneously with the Spine Road design. The west <br />booster station would provide a redundant supply route for the north pressure zone and proposed <br />TCAAP/RCC site. This is considered crucial in the event the existing east booster station malfunctions or <br />experiences a watermain break that would prevent it from being able to supply the north pressure zone. <br />Emergency interconnections exist, but their flow and hydraulic grade (head) capacity are unknown and <br />beyond the scope of this study; therefore, their ability to supply fire flow protection is unknown. <br />Additional modeling was also performed to estimate when the proposed system would require the <br />addition of the proposed tank and pump station in respect to increases in system demands. This is <br />intended to determine when the tank and pump station may be needed depending on the future <br />demands as the development expands.