This page is a practical explainer, not an official notice or compliance determination. If you have a property-specific letter, follow its instructions and ask your issuing agency when unsure.
Why fall and winter maintenance matters
Fallen leaves, sediment and trash can interfere with stormwater flow and plant health. Portland’s Bureau of Environmental Services advises removing accumulated leaves and debris regularly, especially in fall and early winter.
Facilities are different: a vegetated rain garden is not a mechanical vault. Check the property’s operations-and-maintenance (O&M) plan and manufacturer instructions before altering a system.
- Inspect visible inlets and overflow locations from safe ground.
- Check for debris, standing water, eroded areas and damaged landscaping.
- Note anything that may need a qualified maintenance contractor.
Rain gardens, planters and bioswales
Portland’s guidance explains that accumulated leaves can smother healthy plants, eventually build soil and reduce infiltration. For planted facilities, routine care often includes clearing leaves, checking vegetation health and managing invasive plants.
Do not indiscriminately remove plants or regrade a bioswale—its approved planting and grading may be part of the stormwater design. If an agency has inspected the site, its letter and O&M plan take priority.
- Remove litter and accumulated leaf debris without damaging the facility.
- Inspect for dead or stressed vegetation and erosion.
- Ask the agency or an appropriate specialist before major replanting or soil changes.
Catch basins, pipes and structural facilities
Watch for accumulated debris at visible grates and inlets. Underground vaults, filter systems, tanks and deep structures may need specialist equipment, confined-space safety procedures or manufacturer-specific maintenance.
Do not enter a vault, manhole or confined space. For blocked or damaged underground equipment, contact a suitably qualified provider. The City maintains separate lists for vegetated and structural/mechanical work.
- Note the location of the blocked inlet or suspected structure.
- Keep photographs and observations for a contractor or inspector.
- Use qualified professionals for underground, mechanical, or potentially hazardous work.
What to do after a major storm
From a safe location, check whether water flows through inlets and whether erosion, debris or standing water has developed. Document new problems and use your property’s maintenance agreement to determine necessary follow-up.
If you receive an inspection or corrective-action notice, the notice’s deadlines and requirements—not generic seasonal advice—control the next steps.
- Take dated photos of visible issues if safe.
- Make a list of needed work for a maintenance provider.
- Save invoices and inspection notes for any required reporting.
Official sources and forms
- Portland: care for a rain garden or stormwater facility
- Portland: maintenance thresholds and resources
- Clean Water Services: private water quality facility plans
Requirements may change. Confirm deadlines, eligibility, maintenance and permit details with the responsible agency for your address.
Need help with the physical work?
Understand the requirements first. Then find publicly listed providers by facility type, and verify service area, current qualifications and insurance before hiring.