CITY OF DUVALL DEVELOPMENT DESIGN STANDARDS Department of Public Works 14525 Main Street NE PO Box 1300 Duvall, WA 98019 DEVELOPMENT DESIGN STANDARDS CITY OF DUVALL January 2013 - UPDATE City of Duvall Public Works 14701 Main Street NE, Suite A1-B P.O. Box 1300 Duvall, Washington 98019 (425) 788-3434 Originally Prepared by: Hammond, Collier & Wade - Livingstone Associates, Inc. 4010 Stone Way North Seattle, Washington 98103 William Popp Associates Transportation Engineers First Interstate Center, Suite 314 225 108th Avenue N.E. Bellevue, Washington 98004 June 1995 CITY OF DUVALL DEVELOPMENT DESIGN STANDARDS 2013 The City of Duvall has adopted this development design criteria for a two- fold purpose: (1) To set forth specific, consistent street and utility design elements for developers and other private parties constructing or modifying road or right-of-way facilities and/or utilities which require City licenses or permits; and (2) To establish uniform criteria to guide the City’s own construction of new City streets and utilities or reconstruction of existing facilities. In addition, these Standards are intended to support City of Duvall’s goal to achieve affordable housing, provide adequate facilities for development in an efficient manner, provide well-built long lasting utilities and Streets, comply with storm water management and sensitive area policies, and to balance these goals with the general safety and needs of the public. In adopting these Development Design Standards, the City has sought to encourage standardization of design elements where necessary for consistency and to assure so far as practical public safety needs are met. Considerations include safety, convenience, pleasant appearance, proper maintenance, and economics. The Standards also provide requirements for the location and installation of utilities within the right-of-way. The City’s permitting and licensing activities require the adoption of specific, identifiable standards to guide private individuals and entities in the administrative process of procuring the necessary City approval. Yet, the City must have needed flexibility to carry out its general duty to provide streets and capital facilities for the diverse needs of the public. Accordingly, City of Duvall Development Design Standards Revised March 2013 F:\Public Works\Development Guidelines\DDS Manual\2013 Update\Final\2013 revision clean copy Chapters 1-5 Update.doc i these Standards are not intended to represent the legal standard by which the City’s duty to the public is to be measured. These Standards cannot provide for all situations. They are intended to assist but not to substitute for competent work by design professionals. It is expected that land surveyors, engineers, and architects will bring to each project the best of skills from their respective disciplines. These Standards are also not intended to limit unreasonably any innovative or creative effort that could result in better quality, better cost savings, or both. Any proposed departure from the Standards will be judged, however, on the likelihood that such variance will produce a compensating or comparable result, in every way adequate for the street and utility and City resident. City of Duvall Development Design Standards Revised March 2013 F:\Public Works\Development Guidelines\DDS Manual\2013 Update\Final\2013 revision clean copy Chapters 1-5 Update.doc ii TABLE OF CONTENTS CHAPTER 1 GENERAL PUBLIC WORKS 1.1 1-1.00 GENERAL PUBLIC WORKS CONSIDERATIONS.............................................................................. 1.3 1-1.01 Standard Specifications..................................................................................... 1.3 1-1.02 Shortened Designation ..................................................................................... 1.5 1-1.03 Applicability .................................................................................................... 1.5 1-1.04 Definitions and Terms ....................................................................................... 1.5 1-1.05 Changes to Standards ...................................................................................... 1.7 1-1.06 Severability .................................................................................................... 1.7 1-1.07 Design Standards ............................................................................................ 1.8 1-1.08 Plan Review .................................................................................................. 1.19 1-1.09 Construction Control ...................................................................................... 1.20 1-1.10 Inspection .................................................................................................... 1.21 1-1.11 Fees ............................................................................................................ 1.22 1-1.12 Permits ........................................................................................................ 1.22 1-1.13 Bonding ....................................................................................................... 1.25 1-1.14 Utility Locations ............................................................................................. 1.26 1-1.15 Easements.................................................................................................... 1.27 1-1.16 Latecomers Agreements (Recovery Contract) ..................................................... 1.28 1-1.17 Utility Extension ............................................................................................ 1.29 1-1.18 Utility Services Outside of City Boundary ........................................................... 1.29 1-1.19 Traffic Control ............................................................................................... 1.30 1-1.20 Call Before You Dig ........................................................................................ 1.30 1-1.21 Responsibility to Provide Required Road and Infrastructure Improvements .............. 1.30 CHAPTER 2 WATER DESIGN STANDARDS 2.1 2-1.00 WATER....................................................................................................................... 2.1 2-1.01 General .......................................................................................................... 2.1 2-1.02 Design Standards ............................................................................................ 2.2 2-1.03 Connection to Existing Water Main ...................................................................... 2.2 2-1.04 Service Interruption ......................................................................................... 2.2 2-1.05 Water System Materials: ................................................................................... 2.3 2-1.06 Hydrants ........................................................................................................ 2.6 2-1.08 Pressure Reducing Stations and Pressure Reducing Valves (P.R.V.) ........................ 2.12 2-1.09 Service Connection ........................................................................................ 2.13 2-1.10 Steel Casing ................................................................................................. 2.15 2-1.11 Galvanized Iron Pipe ...................................................................................... 2.15 2-1.12 Blowoff Assembly........................................................................................... 2.16 2-1.13 Concrete Bedding and Blocking ........................................................................ 2.16 City of Duvall Development Design Standards Revised March 2013 F:\Public Works\Development Guidelines\DDS Manual\2013 Update\Final\2013 revision clean copy Chapters 1-5 Update.doc iii 2-1.14 Joint Restraint ............................................................................................... 2.16 2-1.15 Backflow Prevention ....................................................................................... 2.16 2-1.16 Reduced Pressure Backflow Assembly with Detector (RPBA) .................................. 2.18 2-1.17 Double Check Valve Assembly .......................................................................... 2.18 2-1.18 Double Check Valve Assembly with Detector ....................................................... 2.18 2-1.19 Backflow Device Resilient Seated Shut-off Valves ................................................ 2.19 2-1.20 Water Main/Sanitary Sewer Crossings ............................................................... 2.19 2-1.21 Staking ........................................................................................................ 2.20 2-1.22 Trench Excavation ......................................................................................... 2.20 2-1.23 Bedding, Backfilling, and Compaction ................................................................ 2.21 2-1.24 Controlled Density Fill ..................................................................................... 2.22 2-1.25 Temporary Street Patching .............................................................................. 2.23 2-1.26 Trench Backfill and Restoration ........................................................................ 2.23 2-1.27 Hydrostatic Tests ........................................................................................... 2.25 2-1.28 Disinfection and Flushing of Water Mains ..........................................................