CC - Agendas - City Council - REGULAR - 7/10/2012

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EXHIBIT A City of Prescott 2012 Water Distribution System Model Update SCOPE OF WORK TASK 2.0 WATER SYSTEM EVALUATIONS 2.1 Existing System Evaluation The current water distribution system will be evaluated using performance criteria that will be agreed upon with the City. The performance criteria may consist of maximum and minimum pressures, maximum velocities, required storage, number of pump and pump station redundancy, and emergency reserves. The performance criteria will reflect the building code that is currently in use by the City. 2.2 Pressure Zone Evaluation Pressure zones in the water distribution system will be evaluated to identify potential ways to simplify the distribution system to reduce operating and maintenance costs, as well as to simplify system operations. The pressure zone schematic that was created previously will be updated to reflect the current water system configuration and also the buildout configuration to aid in simplifying pressure zones. Topographic representations of the consolidated pressure zones will be prepared so that the impact of combining pressure zones can be more easily understood using KML files created by the model that can be displayed using Google Earth. 2.3 Zone 12 Well Supply Evaluation A water delivery strategy for the wells that are and may be constructed in the airport area will be developed. Currently wells serve primarily Zone 12, but as additional well capacity is developed, a means of delivering this water into the North-South Zone is needed so that these wells could augment water supplies from the Chino wells. These additional wells will provide enhanced reliability to the Prescott water system. 2.4 Storage and Booster Evaluation Water storage and booster pump capacity will be evaluated to optimize approaches to effectively provide storage and emergency water supplies. The Prescott water system does not necessarily have storage in all the desired locations, and in some cases there may be excess storage that could benefit the water system if the system was configured accordingly. This evaluation will look at the water storage throughout the water distribution system and a plan will be developed to optimize storage and pumping capabilities. Needed capital improvements will be identified where appropriate. 2.5 Fire Flow Evaluation The capability the water system has of delivering fire flows will be evaluated. Fire flow requirements will be associated with each hydrant that is modeled, based on the land use types that are near the hydrant. Where deficiencies are identified, capital improvements or water system configuration changes will be identified to improve fire flows. System configuration changes could include PRVs from adjacent zones to deliver h:\bd_phx\prescott\water model update\prescott water model update project 06192012.docx 4