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Mr. Michael Grochala April 8, 2020 Page 6 K:\015144-000\Admin\Docs\AUAR - Update 2020\Water Wastewater\MEMO - 040820 - Water.docx All three scenarios will trigger the need for additional municipal water supply infrastructure. The additional wells and storage needed are summarized in Table 4. The storage needs assume that Water Tower No. 3 (1.5 MG) will be constructed and in use by the time of development. Table 4. Supply and Storage Summary Existing System With Scenario 1 With Scenario 2 With 2030 Comp Plan Average Day Demand (MGD) 1.42 3.74 3.91 2.94 Maximum Day Demand (MGD) 3.98 10.78 11.25 8.54 Additional Wells Required N/A 3 to 4 3 to 4 2 Additional Storage Required (MG) N/A 0 to 0.3 0 to 0.4 N/A The City’s existing authorized appropriation volume is 900 million gallons per year (MGY), and the City’s historical water use from 2014-2018 was 470 MGY. All three scenarios are projected to increase the annual water use beyond 900 MGY. Therefore, the City will likely require an amendment to its appropriation volume prior to full build out of the study area. The City’s historical water use shows a decreasing trend in per capita use, which will likely decrease these projections by the time of development. Water Demand Projection Comparison Table 5 summarizes the projected average water demands from the 2005 Original AUAR and this 2020 AUAR Update for the scenarios outlined above. Table 5. Comparison of Average Water Demand Projections Scenario 2005 Original AUAR 2020 AUAR Update Scenario 1 1.86 MGD 2.32 MGD Scenario 2 2.45 MGD 2.49 MGD Scenario 3 2.61 MGD N/A 2030 Comp Plan N/A 1.52 MGD The projected water demands have remained within the parameters discussed in the original AUAR. The expansion and layout of the water supply system will generally conform to the layout identified in the 2005 Original AUAR. The 2005 Original AUAR identified the need for 1.0 MG of additional storage, approximately four additional wells, and trunk and lateral watermains. Water Tower No. 3 (1.5 MG) is currently under construction, and this AUAR Update reiterates the need for three to four additional wells. Computer modeling completed as part of the City’s 2040 Comprehensive Plan Update confirmed the adequacy of the planned 16-inch trunk watermain loop.