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. 

If your property has a stormwater facility, you are responsible for maintaining it according to the Operation and Maintenance (O&M) plan created for your site. The O&M plan explains how to inspect, clean, and maintain the facility so it continues to work properly. If you need help finding your O&M plan, contact the City of Lake Oswego's Stormwater Email (located below). If the City does not have a copy, you may need to request it from Clackamas County Records.

If you need additional help identifying, inspecting, or maintaining your stormwater facility, you may use the Private Water Quality Facility Management Program Inspection Guide for additional guidance.

Stormwater facilities are approved during the development process with the expectation that they will be inspected and maintained on an ongoing basis. Additional requirements can be found in the Lake Oswego Municipal Code.

Stormwater facilities may include:

• Privately owned catch basins, storm drain pipes, and manholes
• Flow control systems, such as detention pipes or detention tanks that temporarily store stormwater
• Infiltration systems, such as drywells or soakage trenches that allow stormwater to soak into the ground
• Water quality treatment systems, such as storm filters or oil/water separators that remove pollutants
• Vegetated stormwater systems, such as swales, detention ponds, and rain gardens that slow, filter, and absorb stormwater

For more information / questions you can reach us at: stormwater@lakeoswego.city