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<br /> <br /> <br />Water Storage Siting Study <br />City of Lino Lakes <br />WSB Project No. 2988-44 Page 4 <br /> <br />3. EXISTING AND FUTURE STORAGE REQUIREMENTS <br /> <br />3.1 Determining Needed Storage <br /> <br />It is recommended that water systems that require fire protection provide enough storage to meet the <br />maximum day demand as well as additional volume for fire protection and pressure equalization. This <br />storage requirement is reduced when the system has excess production capacity in its water wells. The <br />overall equation to determine recommended storage capacity is as follows: <br /> <br />Equation 1. Determining Recommended Water Storage <br /> 𝑻𝑻𝑻𝑻𝑻𝑻𝑻𝑻𝑻𝑻 𝑺𝑺𝑻𝑻𝑻𝑻𝑺𝑺𝑻𝑻𝑺𝑺𝑺𝑺 𝑡𝑡𝑺𝑺𝑺𝑺𝑡𝑡𝑺𝑺𝑡𝑡 = 𝑨𝑨𝑡𝑡𝑨𝑨𝑨𝑨𝑨𝑨𝑻𝑻𝑺𝑺𝑡𝑡 𝑭𝑭𝑭𝑭𝑺𝑺𝑺𝑺 𝑺𝑺𝑻𝑻𝑻𝑻𝑺𝑺𝑻𝑻𝑺𝑺𝑺𝑺 + 𝑬𝑬𝑬𝑬𝑨𝑨𝑻𝑻𝑻𝑻𝑭𝑭𝑬𝑬𝑻𝑻𝑻𝑻𝑭𝑭𝑻𝑻𝑬𝑬 𝑺𝑺𝑻𝑻𝑻𝑻𝑺𝑺𝑻𝑻𝑺𝑺𝑺𝑺 <br /> <br /> Where <br /> 𝑨𝑨𝑡𝑡𝑨𝑨𝑨𝑨𝑨𝑨𝑻𝑻𝑺𝑺𝑡𝑡 𝑭𝑭𝑭𝑭𝑺𝑺𝑺𝑺 𝑺𝑺𝑻𝑻𝑻𝑻𝑺𝑺𝑻𝑻𝑺𝑺𝑺𝑺 = (𝑴𝑴𝑻𝑻𝑴𝑴𝑭𝑭𝑴𝑴𝑨𝑨𝑴𝑴 𝑫𝑫𝑻𝑻𝑫𝑫 𝑼𝑼𝑨𝑨𝑺𝑺+𝑭𝑭𝑭𝑭𝑺𝑺𝑺𝑺 π‘Ήπ‘Ήπ‘Ίπ‘Ίπ‘¬π‘¬π‘¨π‘¨π‘­π‘­π‘Ίπ‘Ίπ‘Ίπ‘Ίπ‘΄π‘΄π‘Ίπ‘Ίπ‘¬π‘¬π‘»π‘»βˆ’π‘­π‘­π‘­π‘­π‘Ίπ‘Ίπ‘΄π‘΄ π‘ͺπ‘ͺ𝑻𝑻π‘ͺπ‘ͺ𝑻𝑻𝒄𝒄𝑭𝑭𝑻𝑻𝑫𝑫) X 𝑫𝑫𝑺𝑺𝑨𝑨𝑭𝑭𝑺𝑺𝑬𝑬 𝑭𝑭𝑭𝑭𝑺𝑺𝑺𝑺 𝑫𝑫𝑨𝑨𝑺𝑺𝑻𝑻𝑻𝑻𝑭𝑭𝑻𝑻𝑬𝑬 (𝑯𝑯𝑻𝑻𝑨𝑨𝑺𝑺𝑨𝑨) <br /> <br />Maximum day demands are evaluated by comparing the City’s average day demands to its peak <br />demands over the past several years. From these values, a peaking factor can be developed that <br />represents the multiplier to compare average and peak day demands. Based on this peaking factor as <br />well as per capita water use and population projections, estimates for the future maximum day demand <br />can be obtained. <br /> <br />Fire fighting volume requirements vary based on land uses and specific commercial, industrial, and <br />institutional uses. Fire requirements are based on guiding documents, including Ten States Standards <br />and the Insurance Services Office (ISO), but the overall fire flow requirements are usually at the discretion <br />of each community. <br /> <br />Equalization storage is the volume required to satisfy water demands that exceed the well pumping <br />capacity throughout the day. During the maximum day water demand, hourly demands vary as a diurnal <br />demand pattern with the maximum hour demand designated as the peak hour demand. Equalization <br />storage is determined by calculating the volume necessary to meet the peak hour demands beyond what <br />the well firm capacity can provide. In the absence of a city-specific diurnal curve, AWWA recommends <br />the required equalization volume to equal 70 to 100% of the average day water demand, or 20 to 25% of <br />the maximum day water demand. Firm pumping capacity is the total capacity of the wells with the largest <br />well out of service. Using these factors, the storage capacity needed for Lino Lakes through year 2040 <br />was calculated. <br /> <br />3.2 Lino Lakes Existing Storage <br /> <br />Existing System Demands and Peaking Factor <br />The City’s existing water system supplies approximately 16,110 individuals. From 2010 to 2015, the <br />average daily water demand was 1.38 million gallons per day, with an average per capita demand of 90 <br />gallons per day over the same time. The maximum day demand from 2010 to 2015 was, on average, 4.92 <br />million gallons. The peaking factor (the ratio between maximum day and average day demands) is 3.57