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This is not the latest version of the SWDM.

Pursuant to King County Council adoption of Ordinances 15051, 15052, 15053 (otherwise known as the Critical Areas Ordinance, Stormwater Ordinance, and Clearing and Grading Ordinance), the Department of Natural Resources and Parks adopted public rules for revising the King County Surface Water Design Manual (SWDM) and the Stormwater Pollution Prevention Manual (SPPM). Adopted in accordance with King County Code, Chapter 2.98, Rules of County Agencies, these public rules became effective on January 24, 2005.

A hard copy of the 2005 SWDM can be purchased at the special sale price of $51 plus tax and shipping from the King County Water and Land Resources Division by calling 206-477-4800, or you may pick the manual up in person and save shipping cost by visiting our office on the 6th floor, 201 South Jackson Street, Seattle.

The entire 2005 SWDM is available online as several separate downloads. The main body of the manual consists of 6 chapters available with the Table of Contents and the Definitions section as a 7 MB Adobe pdf document. This document includes the errata.

Files are available for download in Adobe Acrobat PDF format.

2005 SWDM Main Body (7 MB)

2005 Design Manual Errata:

The printed version of the Manual does not include the errata. If you have a printed version of the Manual, you can download the errata from the page linked here.

2005 SWDM Errata

2005 Design Manual Appendices:

Appendix A - Maintenance Requirements for Flow Control, Conveyance, and WQ Facilities

Appendix B - Master Drainage Plan Objective, Criteria and Components, and Review Process

Appendix C - Small Project Drainage Requirements

Appendix D - Erosion and Sediment Control Standards

2005 Design Manual References:

2005 SWDM References (1.4 MB)

2005 Design Manual Maps:

Application of the Manual's targeted protection levels is determined from the following three application maps of King County. The maps are available here to view or download. This pdf format was chosen to allow the user to zoom in and out, pan the map in any direction, and print the map at the best resolution possible. Click the icon below if you need to download Adobe Acrobat.

Get Adobe Acrobat

2005 Flow Control Applications Map, PDF file

2005 Water Quality Applications Map, PDF file

2005 Landslide Hazard Drainage Areas Map, PDF file

2005 Design Manual Drawings:

Standard drawings from the 2005 King County Design Manual can be downloaded individually in AutoCAD DWG format. Additionally the AutoCAD DWG drawings can be downloaded as a single 9.0 Mbyte file or chapters can be downloaded individually.

Select a group of drawings to download and extract:


Standard Drawings in AutoCAD DWG format

Large ZIP file of all chapters
Download ZIP files of individual chapters:

(9 MB)

2005 Design Manual Small Project Design Tools:

Pre-engineered Stormwater Facilities Documentation Guide

Pre-engineered Small Stormwater/Water Quality Facility Sizes

Use of Stormwater for Fire Protection Document

2005 Design Manual Supporting Documents:

View Summary of Changes

View Stormwater Code KCC 9.04

View Clearing and Grading Code KCC 16.82

For questions about the stormwater website, please contact Blair Scott, Water Quality Planner, King County Stormwater Services Section.