WATER FACILITY DESIGN GUIDELINES (REVISED JANUARY 2021) CITY OF SAN DIEGO PUBLIC UTILITIES DEPARTMENT 9192 Topaz Way, San Diego, CA 92123 Tel (858) 292‐6300, Fax (858) 292‐6310 PREFACE This Guidelines and Standards Book contains information to assist planners and engineers with the design and construction of water facilities. The City’s intent is to ensure uniformity of design concepts, formats, methodologies, procedures, construction materials, types of equipment and quality of work products. These standards have been produced and adopted to encourage exceptional quality while using current technology for all Public Utilities facilities. These Guidelines and Standards are not a substitute for good Engineering. Sound judgement must be exercised in all applications to create quality and cost-efficient facilities. Public Utilities Department management encourages the creation of relationships between project stakeholders that promotes engineering excellence and timely completion of projects. City staff and consultants are encouraged to take the time at the beginning of all projects to identify common goals, common interests, lines of communication, and a commitment to cooperative problem solving. ______________________________ Shauna Lorance Director of Public Utilities Department City of San Diego Water Facility Design Guidelines Public Utilities Department January 2021 SPECIAL ACKNOWLEDGEMENTS Dwayne Abbey Lorne Hampton Alice Altes Debbie Van Martin Yousif Benyamin John Miller Sheila Bose Tung Phung Greg Cross Jesus Ramos Daniel Daft Richard Stevens Catherine Dungca Leonard Wilson Ernesto Fernandez Bill White Tatyana Fikhman Brian Vitelle Charles Gastil City of San Diego Water Facility Design Guidelines Public Utilities Department January 2021 TABLE OF CONTENTS 1. Introduction.................................................................................................................................................... 1-1 1.1 Purpose and Use of Facility Design ........................................................................................ 1-1 1.2 Units of Measurements ............................................................................................................... 1-2 2. Water Demands and Service Criteria .................................................................................................... 2-1 2.1 General .............................................................................................................................................. 2-1 2.2 Service Area ..................................................................................................................................... 2-1 2.3 Land Use and Residential Population .................................................................................... 2-1 2.4 Average Annual Water Demands ............................................................................................ 2-2 2.5 Peak Water Demands ................................................................................................................. 2-3 2.6 Fire Demands .................................................................................................................................. 2-6 2.7 Pressure Criteria ............................................................................................................................. 2-6 2.7.1 Design Pressures ............................................................................................................ 2-6 2.7.2 Domestic Pressure Criteria ......................................................................................... 2-7 2.7.3 Pressure Requirements During Fires ....................................................................... 2-7 2.8 System Reliability .......................................................................................................................... 2-7 2.9 Storage Criteria for Water Systems ........................................................................................ 2-9 2.9.1 Regulating Reservoirs ............................................................................................... 2-11 2.9.1.1 Operating Storage ....................................................................................... 2-11 2.9.1.2 Fire Storage .................................................................................................... 2-12 2.9.1.3 Emergency Storage/Shutdown Storage .............................................. 2-13 2.9.1.4 Total Storage ................................................................................................. 2-14 2.9.2 Forebays ......................................................................................................................... 2-14 2.9.3 Clearwells ....................................................................................................................... 2-14 2.9.3.1 Operating Storage ....................................................................................... 2-15 2.9.3.2 Emergency Storage ..................................................................................... 2-15 2.9.3.4 Total Storage ................................................................................................. 2-16 2.9.3.5 Minimal and Maximum Storage ............................................................. 2-16 3. Transmission and Distribution Pipelines ............................................................................................. 3-1 3.1 General .............................................................................................................................................. 3-1 3.2 Project Presentation ..................................................................................................................... 3-1 3.2.1 Preliminary Alignment .................................................................................................. 3-1 3.2.2 Contract Specifications ................................................................................................ 3-2 3.2.3 Contract Drawings ......................................................................................................... 3-2 3.3 Sizing, Alignment, Easements, and Landscaping .............................................................. 3-2 3.3.1 Sizing and Alignment Criteria .................................................................................... 3-2 3.3.1.1 Horizontal and Vertical Curves .................................................................. 3-3 3.3.1.2 Utility Separations ........................................................................................... 3-3 3.3.1.3 Water Main Abandonment .......................................................................... 3-3 3.3.1.4 Transmission Mains ........................................................................................ 3-3 City of San Diego Water Facility Design Guidelines Public Utilities Department January 2021 3.3.1.5 Distribution Pipelines ..................................................................................... 3-4 3.3.1.6 Prohibited Locations ....................................................................................... 3-4 3.3.2 Pipeline Profile Criteria ................................................................................................. 3-4 3.3.3 Easements ......................................................................................................................... 3-5 3.3.3.1 Private Street Easements .............................................................................. 3-5 3.3.3.2 Access Easements ............................................................................................ 3-5 3.3.3.3 Fire Hydrant Easements ................................................................................ 3-6 3.3.3.4 Abandonment of Water Easements .......................................................... 3-6 3.3.4 Landscaping ..................................................................................................................... 3-6 3.4 Pipeline Materials, Lining, and Coatings .............................................................................. 3-6 3.4.1 Materials ............................................................................................................................ 3-7 3.4.1.1 Asbestos Cement (AC) Pipe ......................................................................... 3-7 3.4.1.2 Ductile Iron (DI) Pipe ...................................................................................... 3-7 3.4.1.3 Polyvinyl Chloride (PVC) Pipe ..................................................................... 3-7 3.4.1.4 Steel (STL) Pipe ................................................................................................. 3-7 3.4.1.5 Reinforced Concrete Steel Cylinder (RCSC) Pipe ................................ 3-7 3.4.1.6 Steel Cylinder Rod Wrapped (SCRW) Pipe ............................................. 3-8 3.4.2 Linings and Coatings .................................................................................................... 3-8 3.4.3 Cathodic Protection ...................................................................................................... 3-8 3.5 Valves, Appurtenances, and Structures................................................................................. 3-8 3.5.1 Valves .................................................................................................................................