2021 Storm and Surface Water Master Plan Update

Bothell City Council voted unanimously to adopt the 2021 Storm and Surface Water Master Plan Update during its Oct. 20, 2020 regular meeting and Public Hearing. City staff held a virtual open house in September 2020 and would like to thank everyone who shared their questions and concerns with us through our online feedback form.

Prior to this update, the City’s Storm and Surface Water Master Plan was last updated in 2015. This plan sets a course for stormwater programs and capital projects for the coming years and addresses current and anticipated regulatory requirements, emerging stormwater management technologies, existing flooding and water quality problems, and the resources the City needs to fully implement its plan.

Adopted 2021 Storm and Surface Water Master Plan Update


All documents below are in PDF format.
Click each tab below to read a brief summary of each section of the document. To read the complete contents of each section or to open the entire document as a PDF, click the document links just above this section.
  1. Program Overview and Evaluation
  2. Project Planning
  3. Watershed Management
  4. Financial Management
  5. Recommended Actions
Section 1 provides an overview and evaluation of the Utility’s functions and recommends program actions where appropriate. Although compliance with federal regulations under the Clean Water Act - National Pollution Discharge Elimination System (NPDES) Permit is a significant driver for the Utility’s program, this Plan Update recognizes that the Utility provides a broader range of services than simply complying with regulations.

Focus areas for the program evaluation and summary overview include:

Systems Operations and Management


  • Inspecting, cleaning, and maintaining the City storm system
  • Identifying and correcting deficiencies in the City-maintained system
  • Requiring private system operators to maintain their systems
  • Identifying and completing Natural Environment Projects

Regulatory Compliance


  • Tracking and responding to NPDES and other state and federal requirements

Stormwater Pollution Control


  • Spill response
  • Illicit connection and discharge elimination
  • Stream and system monitoring, evaluation, and testing
  • Education and outreach targeting behavior change
  • Technical assistance for business owners to repair and maintain their systems

System Expansion (through Land Use and City Projects)


  • Review and inspection of stormwater reports and designs 
  • Creation and updating of stormwater design standards
  • Tracking and integrating new construction into inspections and asset management

Financial Planning and Management


  • Rate setting and billing
  • Financial tracking
  • Asset management funding

Reporting and Record Keeping


  • Internal records management
  • Maintenance and Asset Management database

Summary of Evaluation


No major overhaul or expansion of the Utility is planned during 2021-2025. The Utility is expected to raise rates slightly over time to meet its minimum long-term program needs. Significant effort will be necessary in the next two years to address the following items associated with the City’s NPDES permit: 

Task / Item Due Date
Implement a community-based social marketing strategy
Due Mar. 31, 2021
Watershed delineation and prioritization
Due Dec. 31, 2021
Long-range comprehensive planning
Due Mar. 31, 2022
Implement source control program for existing development Due Dec. 31, 2022
Development of a stormwater management action plan Due Dec. 31, 2022
Low impact development code review Due Dec. 31, 2023
Evaluate and report on behavior change for marketing strategy Due Mar. 31, 2024

Staffing and Equipment Needs


Based on an assessment of its current program, the Utility-funded staffing and equipment levels are adequate to handle existing needs. However, some significant additions to the Utility are being considered through land use changes in the Canyon Park Business Park and future improvements by the City and private development. These additions will be assessed prior to completion of these planning efforts and additional staff and equipment may be included in subsequent rate studies.

Open a PDF of the entire Program Overview and Evaluation section (Section 1) of the draft Master Plan Update.