Stormwater
The City’s stormwater system is not connected to the City’s sewer system. As such, the City conducts a variety of activities focused on the prevention of stormwater pollutants entering the system.
The City is responsible for the design, construction, maintenance, and repair of the public stormwater system. These activities include maintaining stormwater pipes, catch basins (storm drains), water-quality facilities, street sweeping, emergency response, as well as public education and outreach.
To provide comment on any stormwater reports, policies, or permits, please complete this comment form.
As leaves fall, storm drains can get blocked by debris, leading to localized flooding. These drains are vital for keeping streets and sidewalks clear of excess rainwater as well as maintaining stormwater quality standards. Simply clearing leaves and debris from the surface of catch basins near your property with a broom or rake can keep the drainage system functioning well.
The City has a limited number of free drop boxes available to support neighborhood clean-up events through a contract agreement with Republic Services. Neighborhoods can apply for a free drop box to help collect neighborhood leaves.
When it comes to draining your pool, hot tub, or other water features, proper disposal is essential to protect our environment. Never drain pool or hot tub water into storm drains catch basins, the road, your neighbor, or directly out to another body of water. Stormwater catch basins lead directly to local streams like Springbrook and Nettle Creek, where chlorine, bromine, and copper can seriously harm aquatic life. Instead, water should be drained into the sanitary sewer, the system designed to treat and manage chemical-laden water safely.
The City’s Stormwater Management Manual (SWMM) provides guidance and standards for the placement, design, and maintenance of structures used to control runoff, reduce flooding, and prevent pollution from contaminating our local waterways. The manual applies to stormwater management design for public and private development and redevelopment within the City of Lake Oswego.
The City has updated the manual based on stakeholder feedback and revised DEQ water quality requirements. The 2025 draft manual was available for public comment from April 30 to May 30.
Many pet owners don’t realize that dog waste isn’t just a nuisance — it’s a serious environmental pollutant. When left on the ground, especially in urban or suburban areas, dog waste doesn’t just disappear. It gets washed away by rain and irrigation into storm drains and local waterways, creating a chain of problems for ecosystems, public health, and water quality. Join Canines for Clean Water and take the pledge to keep our waterways clear of pet waste!
It is against the law to allow anything other than rain water to enter the stormwater drainage system.
Did you know, in collaboration with the Preservation Society, the City built and maintains a native habitat garden at the Iron Worker's Cottage on Wilbur Street? Landscaping with native plants helps use less water and provides shelter and food for native wildlife. Stop by anytime to visit the garden!
The City is committed to maintaining water quality through multiple programs required by Oregon Department of Environmental Quality (DEQ).
The City has implemented a program which includes inspecting commercial and industrial properties/businesses to help prevent pollutant discharges into our local rivers and streams.
The Backyard Habitat Certification Program provides technical assistance and incentives to Lake Oswego residents who wish to restore native wildlife habitat in their backyards. Participants are guided through three levels of habitat restoration: silver, gold, and platinum.
Helpful stormwater information relevant to industrial and commercial properties
Lake Oswego is committed to protecting the environment of the city and the surrounding area through its Stormwater Management Utility. In an effort to further protect our water sources, Erosion Control Permits are required for construction projects. Read on to learn more.
Public Works Maintenance is responsible for the day to day operation of the stormwater utility. These services include catch basin maintenance, street sweeping, stormwater facility maintenance and emergency utility services.
Stormwater Comment Form