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The City of Portland, Oregon

Portland, Oregon

Welcome to the official web site of the City of Portland, Oregon

General Information: 503-823-4000


1221 SW 4th Avenue, Room 110, Portland, OR 97204

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Environmental Overlay Zone Map Correction Project

  • Peregrine falcons nest on bridges over the Willamette and Columbia River (picture courtesy of Bob Sallinger)

  • Natural areas and parks, like Tanner Springs, provide places to recreate and relax (picture courtesy of Mike Houck)

  • Streams and wetlands, like the Columbia Slough, provide habitat for fish and wildlife

  • Trees on bluffs hold hillsides in place, reducing landslide risk

  • Fish listed under the Endangered Species List (ESA) are found in Portland’s streams, including Crystal Springs

Environmental overlay zones protect Portland’s natural resources, including streams, wetlands, forests and wildlife habitat, and minimize risk of damage to homes from natural hazards, including landslide, flooding and wildfire. The protections also mitigate the effects of climate change, such as reducing air temperature, which helps maintain Portland’s livability and access to nature in the city.

The environmental regulations encourage flexibility and innovation in site planning and provide for development that is carefully designed to be sensitive to the natural resources. The environmental overlay zones have been applied across Portland over the past 30 years through district plans.

The purpose of the Environmental Overlay Zone Map Correction Project is to synchronize the location of the overlay zones with the location of existing natural resources identified in the Natural Resources Inventory. This is part of bringing the zoning code into compliance with the 2035 Comprehensive Plan and ensures resources across Portland are mapped accurately and are regulated in a consistent way. View a self-guided presentation that provides an overview of the project and how the ezones relate to private property.

In July 2018, staff began attending community meetings and performing site visits in the Johnson Creek Watershed and Boring Lava Domes. Spring 2019, staff attend meetings and do site visits in the Northwest Hills and Southwest Hills. Finally, the work will finish up in the Columbia Slough Watershed and Columbia River in summer 2019. Public hearings are expected to begin in spring 2020 and adoption is anticipated in early 2021. Affected property owners will receive notice of the public hearing dates, times, locations and option to provide testimony. 

Map schedule of projects by area


To do this work, BPS staff will use the existing plans, such as the Southwest Hills Resources Protection Plan (1992) or Johnson Creek Basin Protection Plan (1991), to identify which natural resources should be protected. Then environmental overlay zone boundaries will be corrected to match. Staff will not be introducing any new policies or regulations as part of this project. To see a draft of update environmental overlay zones in Johnson Creek and Outer East, view the ezone map.


News and updates

Important information and announcements about the Environmental Overlay Zone Map Correction Project


For the Environmental Overlay Zone Map Correction Project