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The City of Portland, Oregon

Planning and Sustainability

Innovation. Collaboration. Practical Solutions.

Phone: 503-823-7700

Curbside Hotline: 503-823-7202

1900 SW 4th Ave, Suite 7100, Portland, OR 97201

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Frequently Asked Questions (FAQs)

Why is this work needed?
As part of the 2035 Comprehensive Plan, City Council adopted a new Natural Resources Inventory (NRI) for the City of Portland. The existing environmental overlay zones (environmental overlay zones), which have been applied over the past 30 years, do not match the newly mapped resources in the NRI. The City needs to “true up” the environmental overlay zones with the actual features needing protection – streams, wetlands, flood areas, steep slopes, forests and wildlife habitat. This is part of bringing the zoning code into compliance with the new 2035 Comprehensive Plan.

What other benefits are anticipated?
There are other important reasons to protect natural resources:

  • Portland is home to fish and wildlife, including trout, salmon, red-legged frogs, humming birds, warblers, bumblebees and butterflies. The environmental overlay zones protect and conserve streams like Tryon Creek, wetlands like Smith and Bybee wetlands, and habitats like Kelly Butte Natural Area, that fish and wildlife depend on.
  • Streams, wetlands and vegetation also minimize risks associated with natural hazards – including landslides and flooding – by managing stormwater and stabilizing hillsides.
  • Natural resources, especially trees, streams and wetlands, help mitigate the effects of climate change by cooling and filtering the air and providing space for fish and wildlife to live and migrate.
  • Finally, access to nature in the city is part of what makes Portland an amazing place to live, work and visit.

What does “correcting the environmental overlay zones” entail?
Updating the environmental overlay zones means taking the new NRI data that shows where natural resources are located and adjusting the environmental overlay zone boundaries to match. But first, staff need to work with property owners to “ground truth” the NRI data. Staff will be attending meetings in the community and setting up site visits. Please see the Calendar of Events for a schedule.

No new policies or regulations will be introduced as part of this project. BPS will use the existing plans, such as the Southwest Hills Resources Protection Plan (1992) or Johnson Creek Basin Protection Plan (1991), to identify resources to be protected. Then environmental overlay zone boundaries will be corrected to match the intent adopted in those plans.

The work will be done by watershed-by-watershed. From the start, there will be a lot of public engagement with the community to identify and confirm these areas.

Who will be affected?
There are approximately 15,000 properties in Portland with existing environmental overlay zones or significant natural resources. It is anticipated the overlay zone locations on many of these properties will change slightly. Some properties may have a greater expansion or reduction of the environmental overlay zone.

In all cases, the intent is to correct the environmental overlay zones to match the resources to be protected, including streams, wetlands, flood area, steep slopes, forests and wildlife habitats. Please use Ezone Map to look up your property and see if the ezones and changing. 

What is protected today?
The City of Portland’s zoning map shows the location of the environmental overlay zones. There are three types of environmental overlay zones: conservation (c), protection (p) and Pleasant Valley (v).

Conservation (c) overlay zones are applied to natural resources that are important and where environmentally sensitive development can minimize impacts to the resources. Protection (p) overlay zones are applied to natural resources that are of high enough significance that impacts should avoided all together and only occur in rare circumstances. Pleasamt Valley (v) overlay zones are applies to the resources and a wide buffer around the resource that are intended to be conserved and enhanced as the area develops.

The environmental overlay zones have been applied across Portland over the past 30 years through district plans.

Where will the corrections happen?
The environmental overlay zones may be corrected where the existing overlay zone boundary does not match the natural resource features that are supposed to be protected. These corrections may be expansions or reductions in the environmental overlay zone – negligible or significant – depending on how much of the natural resource needs to be protected based on that area’s specific conservation plan.

The figure below is an example of the existing environmental overlay zones (cross-hatched area) and locations of streams and riparian areas. In this example, the streams are not protected in a consistent way, leaving one stream segment unprotected (circled in yellow). The result of the map correction may be to apply environmental overlay zone to unprotected stream segment (it should be in a cross-hatched area).

Map showing area consideration

What if I get new environmental overlay zones?
The environmental overlay zone should be applied to natural resources on your property that need to be protected. Ideally, that portion of your property should be left natural. However, many of the natural resources in Portland have been altered by yards, driveways, and even portions of houses and buildings. But these altered resources still provide important functions, like flood storage and wildlife habitat. Additional impacts to the resources should be minimized.

That doesn’t mean you can’t use your property in the environmental overlay zone. It does mean that you need to understand the environmental overlay zone regulations, which guide new development to reduce impacts on the natural resources. The environmental regulations are found in zoning code Chapter 33.430.

Does this mean I can’t plant a garden in my yard?

You can plant a garden in your yard. If you already have a permitted lawn or landscaped area in the environmental overlay zone and you want to change it to a garden, that is allowed if you don’t remove any trees. You can also maintain existing gardens, lawns, and other planted areas in environmental overlay zones; including adding new irrigation and installing new plants.  New plants must not be listed as nuisance on the Portland Plant List.

If you want to add a new garden to a portion of the environmental overlay zone that is not already landscaped, you can if the garden is less than 500 square feet in size, no trees are removed, it is not close to a stream or wetland and you don’t exceed the maximum disturbance area limitations for your base zone. However, if you can put the garden in an existing lawn or completely outside the environmental overlay zone, that is the preferred alternative. Please see zoning code 33.430.080.D.9 for the exact requirements.  

Does this mean I can’t repave my parking area?
You can maintain, repair or even replace parking areas and other existing structures, like houses, and buildings in the environmental overlay zone as long as the footprint of the parking area or structure is not increased. Please see 33.430.080.C for the exact requirements. 

Does this mean I can’t add a deck to my house?
Expanding the footprint of development in the environmental overlay zone – making it bigger – is more complicated. It depends on how much of your property is in the environmental overlay zone and how much of the site has already been developed. Please see 33.430.140.A-S for more information.