Storm and Surface Water Projects

Stormwater capital projects are developed through a strategic planning process. Each project begins as a maintenance issue or identified need through basin planning, drainage complaints, or other studies.
To become a project, a planning-level assessment is completed to prioritize the project for implementation. We estimate the amount of time and cost needed to realistically finish the project. The project can then be added to the 6-year Stormwater Capital Improvement Plan. Using this plan, the projects are programmed into the Stormwater Division's 2-year budget and work plan.
6-Year Stormwater Capital Improvement Plan
Capital projects address site-specific issues, such as flooding or necessary repairs. These projects are included in the City’s six-year Stormwater Capital Improvement Plan (CIP).
- 2023-2028 Stormwater Capital Improvement Plan
- Storm Pipe Rehabilitation Program (project page coming soon!)
- Storm Facility Retrofit Program (project page coming soon!)
- Storm Facility Restoration Program (project page coming soon!)
- SW-500 Projects ($50-$300K)
- Loree Estates Outfall Diversion
- Inglewood 207th Ave NE Outfall
Maintenance Projects
The Operation and Maintenance Manager and the Senior Stormwater Program Manager jointly oversee operations and maintenance of City-owned stormwater facilities. Work is accomplished by City inspectors, maintenance crews, and contractors.
Maintenance activities are required at several hundred facilities. Activities include managing vegetation, removing sediment and debris, and repairing erosion with grading and stabilization. Additionally, materials and infrastructure sometimes need to be replaced. Cartridges and filtration material (sand filters, bioswales) must be replaced periodically. Likewise, infrastructure such as catch basins, manholes, inlets, and outlets require maintenance and replacement.
- Annual Ditch and Drainage Maintenance (includes SW-100 Small Drainage Resolutions Program)
- Enhanced Maintenance Plan - Street Sweeping
- Vegetation Maintenance Strategy
Planning Projects
The City of Sammamish is working on several planning projects related to stormwater. Project pages will be developed as more information is available.
- 2025-2029 NPDES Permit
- Stormwater Retrofit Strategy
- Citywide Comprehensive Plan involvement
- Surface Water Master Plan (also known as the Surface and Stormwater Comprehensive Plan)
Basin Plans
Basin plans provide comprehensive analysis of surface water characteristics, issues and solutions to identified problems. The framework for the plans are the area where water naturally drains (i.e. the drainage basin).
The East Lake Sammamish Basin Plan was completed by King County in the early 1990s. The City updated several sub-basins included in that plan (including Inglewood and Thompson) in 2009.
Additional plans are prioritized and continue to be added to update conditions that have changed since the 1990s. Updates provide new analysis and recommendations to protect natural resources and improve water quality and drainage concerns.
In the 2023-2024 biennial budget, the Stormwater program plans to complete one basin plan every two years.
- Beaver Lake Management Plan 2007
- Inglewood Subbasin Plan Entranco 2005
- Inglewood Subbasin Plan 2011
- Pine Lake Water Quality Study 2010
- Thompson Subbasin Plan Parametrix and Windward 2011
- Zackuse Basin Plan 2019
- Laughing Jacobs Basin Plan 2022
- Pine Lake Creek Basin Plan (project page coming soon!)
King County Plans and Reports
The City of Sammamish was incorporated in 1999. For several years, the City contracted with King County through an interlocal agreement for stormwater services. The City still contracts with King County for stormwater billing and other support.