Agenda - Parks and Recreation Commission - 04/10/2014

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SECTION 6 WATER STORAGE AND DISTRIBUTION SYSTEM A. PURPOSE The purpose of this Section is to evaluate water storage and water system distribution improvements needed to ensure adequate pressure and fire flow are available for both current and future conditions. B. GENERAL The water distribution system for the City of Ramsey was modeled using the Watercad Hydraulic Network Model. The computer network model is used to analyze steady state flows for pipe distribution systems. The information required by the model includes data such as diameter, length, and Hazen -Williams C Factor (the pipes roughness factor) for each pipe in the system. Other data required include ground elevation of pipe junctions, elevated storage water level and water demand on the system. The model developed for the City of Ramsey's distribution system is based on the previous Cybernet Model of the City's water system. This model was calibrated to match known conditions. This model is then utilized to evaluate potential water storage facility sites, and water distribution system improvements. C. WATER SYSTEM SIMULATION CRITERIA In designing and analyzing system simulations, a set of design criteria was established. Recommended Standards for Water Works recommends that a minimum pressure of 20 psi be maintained at all times in the system, with normal working pressure in the 35-70 psi range. Static pressure higher than 100 psi is not recommended as higher pressures increase the frequency of watermain breaks. Fire flow is determined at a pressure of 20 psi in order to correlate with the guidelines of the Insurance Services Office (ISO). The water tower levels were established at one-half total capacity during fire flow simulations. City of Ramsey, Minnesota — M21.34343 Page 6-1 Water System Study Prepared by Bolton & Menk, Inc.