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<br />II <br />II <br />II <br />II <br /> <br />SECTION 5 <br /> <br />WATER DISTRIBUTION SYSTEM <br /> <br />Description of Existing System. <br /> <br />The existing distribution system is shown on Exhibit No.8. The system is <br />presently fed by three lines (12", 16", 20") from the treatment plant. <br /> <br />II <br /> <br />There exists 3.5 mg of storage at the treatment plant and 1.5 mg of storage <br />northwest of the downtown area. <br /> <br />II <br /> <br />II <br />il <br />II <br />II <br />[I <br />II <br />II <br /> <br />To evaluate the capability of the present system to meet present demands of <br /> <br /> <br />the total area served, a Hardy Cross analysis was run on the existing system. <br /> <br /> <br />The system was analyzed under peak flow conditions. The peak flow or maximum <br /> <br /> <br />hour demand as discussed in Section 2 is usually 1.5 times the maximum day <br /> <br /> <br />demand. In 1971 the peak flow was 1.5 x 8.27 = 12.4 mgd = 8620 gpm. Based <br /> <br /> <br />on the Hardy Cross analysis during peak flow conditions 6680 gpm entered the <br /> <br /> <br />system from the treatment plant and 1940 gpm entered the system from the 1.5 mg <br /> <br /> <br />storage tank. After entering the system, water flows out of the system to the <br /> <br /> <br />residential customers and outside districts and users at the appropriate locations <br /> <br /> <br />in the system. <br /> <br />-I <br /> <br />The residual pressures as obtained from the analysis are shown on Exhibit No.8. <br /> <br /> <br />The areas of low pressure are basically in the Lincoln Park and Prospect Heights <br /> <br /> <br />areas. The pressures vary from a low of 11 psi at Poplar Street and Lombard <br /> <br /> <br />Avenue to a high of 99 psi in the vicinity of 2nd Street and River Street. <br /> <br /> <br />Normally residual main pressures must be above 40 psi to maintain desired flow <br /> <br /> <br />at the faucet of the residence being served. Although the distribution <br /> <br /> <br />network used in the analysis did not include the area around Jewett and <br /> <br /> <br />Park Avenue,. City officials indicate low pressure and volume problems exist <br /> <br /> <br />there. The remainder of the area served in general has sufficient pressures <br /> <br /> <br />available to maintain adequate service. <br /> <br />I <br /> <br />~ <br /> <br />I <br /> <br />Proposed Improvements in System to Handle 1993 Demand. <br /> <br />-I <br />~ <br /> <br />In developing a distribution network to serve the 1993 demand the first item <br /> <br /> <br />would be to correct the low pressure areas that exist at the present time. <br /> <br />11 <br />.. <br /> <br />I <br /> <br />5-1 <br />