We apply scientific knowledge and innovation to improve watershed health for community benefit.

Scoggins Dam and Flow Restoration

Clean Water Services (CWS), local cities and water providers are working to secure a long-term water supply for municipal, industrial, agricultural, and environmental needs. CWS staff partners with water resource managers to explore opportunities to improve watershed health and enhance stream flows. In addition to our timed releases with the Hagg Lake facility, we also work with farmers along Gales and McKay Creeks to enhance stream flows and support watershed health.

Regional Stream and Wetland Enhancements

We’re working on a variety of projects, including aquatic habitat enhancement, riparian planting, and wetland restoration across urban and rural areas of the Tualatin River Watershed.

• Enhancing urban streams and wetlands is an investment that pays dividends in many ways.
• CWS partners with the agricultural community to meet regulatory obligations and mutual goals for watershed health. Learn about Enhanced CREP and VEGBAC programs for rural landowners.

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Water Quality Credit Trading Annual Report

A watershed-based NPDES permit allows CWS to offset thermal loads from the Rock Creek, Durham, and Forest Grove treatment facilities by implementing a water quality credit trading program for temperature. The 2024 Water Quality Credit Annual Report (PDF) offers information on temperature-related activities during the period of January 1 through December 31, 2024.

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Sanitary Sewer Master Plan

CWS is responsible for planning improvements to its facilities and the collection system and creating a Sanitary Sewer Master Plan. The intention of a master plan is to identify improvements to provide adequate capacity for current and future needs. CWS prepares new plans approximately every 10 years and considers a 20-year planning horizon. CWS takes a unique approach to sanitary planning by integrating its Sanitary Sewer Master Plans and Water Resource Recovery Facility Master Plans. CWS develops the plans with governmental partners by projecting residential, commercial, and industrial redevelopment and growth while anticipating increasingly stringent regulatory requirements. CWS develops geographically based improvement plans to the conveyance and treatment system using traditional and state-of-the-art treatment technologies to meet and exceed regulatory requirements.

East Basin Master Plan

• Conveyance System and Durham Water Resource Recovery Facility
• The Clean Water Services Board of Directors adopted the plan April 5, 2022, by Resolution and Order 22-6.
• Serving Tigard, Tualatin, Sherwood, King City, Durham, and portions of Beaverton, Portland, and Lake Oswego.

Executive Summary (PDF)

Comprehensive Technical Memos:

• TM 01 – Goals and Planning Criteria (PDF)
• TM 02 – Study Area Characteristics (PDF)
• TM 03 – Climate Sensitivity (PDF)
• TM 04 – Regulatory Update (PDF)
• TM 16 – Geotechnical Seismic Hazards Assessment (PDF)

Conveyance System

Conveyance Technical Memos (TM):

• TM 05 – Flow Development (PDF)
• TM 06 – Model Development (PDF)
• TM 07 – Infiltration and Inflow Evaluation (PDF)
• TM 08 – Conveyance System Alternatives (PDF)
• TM 09 – Conveyance Implementation Plan (PDF)

Durham Facilities Plan

Durham Water Resource Recovery Facilities Plan Technical Memos:

• TM 10 – Flow and Load Projections (PDF)
• TM 11 – Liquids Treatment Process Capacity (PDF)
• TM 12 – Solids Capacity Evaluation (PDF)
• TM 13 – Liquids Treatment Process Alternatives (PDF)
• TM 14 – Solids Treatment Alternatives (PDF)
• TM 15 – Recommended Plan (PDF)

West Basin Master Plan

• Conveyance System and Rock Creek, Hillsboro, and Forest Grove water resource recovery facilities.
• The Clean Water Services Board of Directors adopted the plan November 4, 2025, by Resolution and Order 25-18. 
• Serving Hillsboro, Forest Grove, Cornelius, North Plains, Banks, Gaston, Aloha, North Bethany, and portions of Beaverton. 

Part 1 – Executive Summary

Part 2 – Basis of Planning

• TM 01 – Planning Basis (PDF)
• TM 02 – Study Area Characteristics (PDF)
• TM 03 – Flow and Load Projections (PDF)
• TM 04 – Regulatory Update (PDF)

Part 3 – Conveyance

• TM01 – Conveyance – Executive Summary (PDF) 
• TM02 – Conveyance Planning Basis (Design Criteria, Design Storm Update, and Climate Sensitivity) (PDF)
• TM03 – Conveyance – Flow Development (PDF)
• TM04 – Conveyance Model Development (PDF) 
• TM05 – Conveyance – Existing System Capacity Analysis (PDF)
• TM06 – Infiltration and Inflow Analysis, Cost Effectiveness Analysis (PDF) 
• TM07 – Conveyance Improvements Alternatives Analysis (PDF)
• TM08 – Conveyance Capital Project Implementation Plan (PDF)
• TM09 – Conveyance Seismic Resiliency (PD

Part 4 – Water Resource Reclamation Facilities 

• Executive Summary – Forest Grove, Hillsboro, and Rock Creek WRRFs 
• TM01 – West Basin Alternatives CAMP Documentation (PDF)
• TM02 – Rock Creek WRRF Capacity Assessment (PDF)
• TM03 – Rock Creek Grit Removal Capacity Assessment (PDF)
• TM04 – Rock Creek Secondary Treatment Expansion (PDF)
• TM05 – Rock Creek WRRF Tertiary Expansion Evaluation (PDF) 
• TM06 – Rock Creek Digester Capacity Evaluation (PDF)
• TM07 – Rock Creek WRRF Odor Control Evaluation (PDF)
• TM08 – Dedicated Solids Transfer Pipeline Evaluation (PDF)
• TM09 – Rock Creek Hydraulic Capacity Analysis (PDF)
• TM10 – Forest Grove WRRF Capacity Assessment (PDF)
• TM11 – Hillsboro WRRF Capacity Assessment (PDF)
• TM12 – Forest Grove WRRF Aeration Evaluation (PDF)
• TM13 – Hillsboro WRRF Headworks and Grit Removal System Evaluation (PDF)
• TM14 – Forest Grove Hydraulic Capacity Analysis (PDF)
• TM15 – Hillsboro Hydraulic Capacity Analysis (PDF)
• TM16 – Rock Creek Implementation Plan (PDF)
• TM17 – Forest Grove Implementation Plan (PDF)
• TM18 – Hillsboro Implementation Plan (PDF)