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.

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Annual Residential Stormwater Facility Inspections

Stormwater facilities help collect, slow down, filter, and safely manage rainwater before it enters local streams, rivers, or the ground. Regular inspections and maintenance help these systems work properly, reduce flooding, and protect water quality.

The City of Lake Oswego is required by its National Pollutant Discharge Elimination System (NPDES) permit to make sure privately owned stormwater facilities are properly maintained. To meet this requirement, property owners or facility operators must inspect their stormwater facilities each year and submit an annual inspection and maintenance report to the City.

Stormwater facilities help collect, slow down, filter, and safely manage rainwater before it enters local streams, rivers, or the ground. Regular inspections and maintenance help these systems work properly, reduce flooding, and protect water quality.

The City of Lake Oswego is required by its National Pollutant Discharge Elimination System (NPDES) permit to make sure privately owned stormwater facilities are properly maintained. To meet this requirement, property owners or facility operators must inspect their stormwater facilities each year and submit an annual inspection and maintenance report to the City.

Leaf Disposal and Helpful Tips

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.

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.

Street Sweeping

The City sweeps every neighborhood on a regular rotation using our three street sweepers. They work zone by zone, Monday through Friday, and some weekends. While they can sweep the whole city in about a month during spring and summer, fall and winter take longer due to heavy leaf and pine needle buildup. Thank you for your patience as crews make their way through each zone.

You can help sweeping be more efficient by keeping leaves and yard debris out of the street. Please do not rake, blow, or pile leaves into the roadway, as this clogs and damages equipment and is also against City code.

The City sweeps every neighborhood on a regular rotation using our three street sweepers. They work zone by zone, Monday through Friday, and some weekends. While they can sweep the whole city in about a month during spring and summer, fall and winter take longer due to heavy leaf and pine needle buildup. Thank you for your patience as crews make their way through each zone.

You can help sweeping be more efficient by keeping leaves and yard debris out of the street. Please do not rake, blow, or pile leaves into the roadway, as this clogs and damages equipment and is also against City code.

Report a Spill or Water Quality Issue

It is against the law to allow anything other than rain water to enter the stormwater drainage system.

It is against the law to allow anything other than rain water to enter the stormwater drainage system.

Stormwater Incentives

Healthy streams, rivers, and lakes start in our own neighborhoods. The City of Lake Oswego offers free stormwater incentives to help residents reduce pollution, protect water quality, and make environmentally friendly choices at home. Pick up environmentally friendly yard care tools like garlic spray and insecticidal soap, or have your pup join the Canines for Clean Water program.

It's an easy way to reduce pollution, keep pet waste out of our waterways, and help keep Lake Oswego clean. Complete this form.

Healthy streams, rivers, and lakes start in our own neighborhoods. The City of Lake Oswego offers free stormwater incentives to help residents reduce pollution, protect water quality, and make environmentally friendly choices at home. Pick up environmentally friendly yard care tools like garlic spray and insecticidal soap, or have your pup join the Canines for Clean Water program.

It's an easy way to reduce pollution, keep pet waste out of our waterways, and help keep Lake Oswego clean. Complete this form.

Stormwater Management Manual

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.

In 2025, the manual was updated based on stakeholder feedback and revised DEQ water quality requirements. The latest version of the manual is here.

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.

In 2025, the manual was updated based on stakeholder feedback and revised DEQ water quality requirements. The latest version of the manual is here.

Permits, Plans, and Reports

The City is committed to maintaining water quality through multiple programs required by Oregon Department of Environmental Quality (DEQ).

The City is committed to maintaining water quality through multiple programs required by Oregon Department of Environmental Quality (DEQ).

Canines for Clean Water

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!

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!

Storm Drain Marking Program

Did you know that anything goes down a storm drain can end up in our local rivers, streams, and even the ocean? Our Storm Drain Marking Program helps raise awareness in the community by placing bright, visible markers on storm drains. These markers serve as reminders that only rain should go down the drain, preventing harmful pollutants from entering our water systems.

Did you know that anything goes down a storm drain can end up in our local rivers, streams, and even the ocean? Our Storm Drain Marking Program helps raise awareness in the community by placing bright, visible markers on storm drains. These markers serve as reminders that only rain should go down the drain, preventing harmful pollutants from entering our water systems.

Industrial and Commercial Stormwater Program

The City of Lake Oswego’s Industrial and Commercial Stormwater Program helps prevent pollution from businesses from entering local streams, rivers, and the public stormwater system.

The City of Lake Oswego’s Industrial and Commercial Stormwater Program helps prevent pollution from businesses from entering local streams, rivers, and the public stormwater system.

Backyard Habitat Certification Program

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.

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.

Business Requirements

Helpful stormwater information relevant to industrial and commercial properties

Helpful stormwater information relevant to industrial and commercial properties

Erosion Control Permit and Information

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.

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.

Stormwater Maintenance

Public Works 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.

Public Works 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.

Contact Information

Megan Charbonneau - Stormwater Quality Coordinator
503-534-2683

To report a spill or water quality concern, please call 503-635-0280 during regular business hours, or 503-635-0238 after-hours.

Links

Stormwater Comment Form