09/02/2008 Council Packet - Laserfiche WebLink

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WATER STORAGE Water storage facilities serve several purposes in a water system, including capacity to meet peak demands which exceed the capacity of the supply source(s). They also help to maintain constant system pressure, and provide for smooth pumping operation by minimizing the amount of starting and stopping cycles required to keep up with customer demand. Storage facilities are equally important to assure water supply during emergency conditions such as power outages, supply facility breakdowns, and fire fighting needs. The City of Lino Lakes currently has two elevated water storage tanks, one located east of I -35E, and the other located north and west of I -35W. The tanks are described in Table D, below. TABLE 8 -5 STORAGE TANKS Tank Capacity Overflow Elevation Tower No. 1 1,000,000 gal 1054.5 ft Tower No. 2 1,000,000 gal 1054.5 ft SCADA CONTROL SYSTEM The City of Lino Lakes utilizes a Supervisory Control and Data Acquisition (SCADA) system. SCADA systems have become the municipal standard for water systems in recent years. They typically consist of a central, computer -based control system that communicates with each "remote" facility (i.e., well, tank, lift station, etc.) through one of several types of telemetry. The radio based telemetry system removes the City's dependence on and cost to lease phone lines. The use of radio SCADA systems can control operations such as starting and stopping equipment, monitoring for intrusion or facility failure, and warning of failures which could result in a dangerous or costly situation. Additional benefits include data storage, report generation, and trending to establish important operating information for historical, design, and performance report preparation. Peak day well production during this period averaged approximately 342 gpcd. As can be seen, this number is just an arithmetic average, with actual values varying by year. The highest value of 423 gpcd, or 124% of the average peak was achieved in 2007. The lowest value of 263, or 77% of the average peak was achieved in 2002. FUTURE WATER SYSTEM As discussed previously, population and peak day water use can be used to determine the peak day per capita water utilization. This parameter is expressed in units of gallons per capita per day (gpcd), and can vary from year to year, becoming larger in drought years and smaller in wet years due to the variation in irrigational and recreational uses. Estimating per capita demands plays an important role in projecting future water system needs, and will determine how large the watermain infrastructure must be, as well as when and where they are required. When projecting future water use, population and per capita consumption are not the only variables that can influence the magnitude of future demands. Consideration must also be given to changing trends in the amount of commercial and industrial development presently served, as well as their anticipated future requirements. There are no known major water users planning to locate in Lino Lakes at the time of this report. Thus, future commercial and industrial, as well as residential, irrigation, and other water use is assumed to remain consistent with historical patterns. As mentioned above, the peak day per- capita use averaged about 342 gpcd. It is assumed that as Lino Lakes grows and matures, demand for reduction and water conservation efforts, better resource management, and maturing lawns and landscaping will lower the peak day per- capita water use, as reflected below. By projecting population, and establishing anticipated peak per capita consumption rates, we are able to predict the future consumptive rates that the supply and treatment facilities will be required to satisfy. Table 8 -6 contains estimates for peak day demands through the design period. 8 -8 • • •