Clean Water Services’ Design and Construction Standards describe administrative and technical requirements for development and construction activities that occur within CWS’ jurisdictional boundary.
The Standards address a range of topics including the design and construction of sanitary sewer and surface water management systems, erosion control methods, and natural resources protection.
The current Standards, Resolution and Order (R&O) 26-25 apply to new projects, with an application date on or after November 1, 2026.
Projects that are in progress, with a land use application accepted by the land use authority prior to November 1st, may proceed under the previous standards, R&O 19-5 as amended by R&O 19-22, or the current Standards. Projects with a limited scope that do not require a land use decision may proceed under the previous or current standards if the date of application is prior to November 1st.
Design & Construction Standards (Current): R&O 26-25
R&O 26-25
- Text only document, excluding Standard Details (PDF)
- R&O 26-25 (PDF)
- Table of Contents (PDF)
Chapters
- Chapter 1 (PDF) – General Requirements and Administrative Provisions
- Chapter 2 (PDF) – Administrative Procedures
- Chapter 3 (PDF) – Sensitive Areas and Vegetated Corridors
- Chapter 4 (PDF) – Runoff Treatment and Control
- Chapter 5 (PDF) – Conveyance Design
- Chapter 6 (PDF) – Erosion Prevention and Sediment Control
- Chapter 7 (PDF) – General Construction Specifications for Conveyance Systems
- Chapter 8 (PDF) – Technical Specifications for Conveyance Systems
- Chapter 9 (PDF) – Wastewater Pump Stations and Force Mains
- Chapter 10 (PDF) – Septic Tank Effluent Pump (STEP) Systems
Appendix A – Planting Requirements
- Appendix A (PDF) – Planting Requirements
Appendix B – Standard Details
- Appendix B Table of Contents (PDF)
- Manholes and Appurtenances 010 – 270 (PDF)
- Storm Structures 300 – 407 (PDF)
- Pipes 500 – 620 (PDF)
- Stormwater Management 700 – 794 (PDF)
- Erosion Control 800 – 950 (PDF)
- Pump Stations 1000 – 1082 – (PDF)
- Flow Monitoring, Testing Forms, Computational Aids 1100 – 1285 (PDF)
- AutoCAD Files
- DWG Files Detail 010 – 620 (ZIP, 41.2MB)
- DWG Files Detail 700 – 794 (ZIP, 30MB)
- DWG Files Detail 800 – 1082 (ZIP, 44.5MB)
- DWG Files Detail 1100 – 1285 (ZIP, 8.5MB)
Hydromodification Map Web Tool
- Hydromodification Map web tool – This tool assists applicants in determining the necessary hydromodification approach detailed in Chapter 4 (Section 4.03), R&O 19-22. Submit comments, issues, or other feedback on the mapping tool to dcstandards@cleanwaterservices.org.
Previous Standards (not current)
Resources
- Approved Products List (PDF)
- Low Impact Development Approaches Handbook
- LIDA & Homebuilding Fact Sheet (PDF)
- Erosion Prevention & Sediment Control Manual (PDF, 15.5MB)
- Tualatin River Urban Stormwater Tool (TRUST): currently unavailable for download