Environmental Overlay Zone Map Correction Project

Columbia Slough and Columbia River Mapping Protocol Summary

Public Review Draft 1 June 2019

Table of Contents

1. INTRODUCTION Page 1 2. PROJECT BACKGROUND Page 3 3. RESOURCE SITE BOUNDARIES Page 7 4. NATURAL RESOURCE DESCRIPTIONS Page 8 5. SUMMARY OF ESEE DECISIONS AND CROSSWALK TO NRI Page 10 6. ENVIRONMENTAL OVERLAY ZONE MAPPING PROTOCOL Page 12

Do you have feedback on this draft?

Bureau of Planning and Sustainability staff would like to hear your questions and comments on the Draft Columbia Slough and Columbia River Mapping Protocol Summary.

Please send comments by July 31, 2019 to: Bureau of Planning and Sustainability 1900 SW 4th Avenue, Suite 7100 Portland, OR 97201 Or via email to [email protected]

If you have questions about the Environmental Overlay Zone Map Correction Project, please call 503-823-4225 or email [email protected]

Environmental Overlay Zone Map Correction Project Columbia Slough and Columbia River Mapping Protocol Summary

1 Introduction

The purpose of this memo is to summarize the technical steps followed to correct the locations of environmental overlay zones applied from 1989 – 2010 in the Columbia Slough Watershed and portions of the Columbia River, using new feature information (e.g., streams, wetlands, vegetation) in the adopted Natural Resource Inventory (2012). The Columbia South Shore, which is not subject to Zoning Code Chapter 33.430, Environmental Zones, is not part of this project.

Environmental overlay zones and their associated regulations in Zoning Code Chapter 33.430 protect Portland’s natural resources, including rivers, streams, wetlands and wildlife habitat, and minimize risk of damage to homes from natural hazards, including landslides, flooding and erosion. 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 natural resources.

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 project 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.

This memo provides a summary of the GIS mapping protocols used to create the draft updated environmental overlay zones for the Columbia Slough Watershed and portions of the Columbia River in Portland.

Photo 1: Columbia Slough

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Definitions

Vegetation Vegetation Patch: An area of contiguous vegetation greater than ½ acre in size containing a distinct pattern, distribution, and composition of vegetation relative to surrounding vegetated and non-vegetated areas. Forest: Trees with their crowns overlapping, generally forming 60-100% of cover. Woodland: Open stands of trees with crowns not usually touching, generally forming 25-60% of cover. Tree cover may be less than 25% in cases where it exceeds shrubland and herbaceous vegetation. Shrubland: Shrubs generally greater than 0.5 m tall with individuals or clumps overlapping to not touching, generally forming more than 25% of cover with trees generally less than 25% of cover. Shrub cover may be less than 25% where it exceeds forest, woodland, and herbaceous vegetation. Vegetation dominated by woody vines (i.e., blackberry) is generally included in this class. Herbaceous: Herbs (graminoids, forbs, ferns and shrubs less than 0.5m tall) dominant, generally forming at least 25% of cover. Herbaceous cover may be less than 25% where it exceeds forest, woodland and shrubland vegetation. This includes shrubs less than 0.5 m tall.

Waterbodies Stream: A stream is a channel that has a defined bed and bank and carries water continuously for a week or more during at least the wet season (October through April). Streams may be naturally occurring or may be a relocated, altered or created channel. Streams may contribute water into another waterbody or the water may flow into a pipe or culvert. Streams may flow for some distance underground. Streams are also referred to as drainageways, ditches, or drainages in other City of Portland reports, codes and rules or by other agencies including but not limited to Oregon Department of State Land or US Army Corps of Engineers. Streams include: • the water itself, including any vegetation, aquatic life or habitat; • the channel, bed and banks located between the top-of-bank; the channel may contain water, whether or not water is actually present; • intermittent streams, which flow continuously for weeks or months during the wet season and normally cease flowing for weeks or months during dry season; • sloughs, which are slow-moving, canal-like channels that are primarily formed by tidal influences, backwater from a larger river system, or groundwater; • oxbows and side channels connected by surface flow to the stream during a portion of the year; and • drainage from wetlands, ponds, lakes, seeps or springs, which may or may not form a defined bed and bank. Drainage: A drainage is an area on the land that conveys flowing water for only hours or days following a rainfall. If a drainage drains water from a wetland, pond, lake, seep, or spring even if it does not have a defined bed and bank, then it is classified as a stream. Roadside Ditch: A roadside ditch is a constructed channel typically parallel and directly adjacent to a public or private road. A roadside ditch is designed to capture and convey stormwater runoff from the road and is routinely cleaned (i.e., mechanically scoured or scraped of vegetation and debris) to maintain water conveyance capacity. Naturally occurring streams and drainages that have been relocated due to the construction of a road are not considered a roadside ditch. Wetlands: Areas where shallow water is present long enough to create hydric soils and could support hydrophilic vegetation, although due to landscaping, seeding or mowing hydrophilic vegetation may not be present.

Hazards Floodplain: Areas with a 1% or greater chance of flooding in any given year and areas that were inundated with water during the 1996 floods. Steep slopes: Land with a 25% or greater slope.

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2 Project Background

Beginning in 1989, Portland adopted natural resource conservation and protection plans for areas in the city where there are significant natural resources. Following a process laid out by Oregon State Land Use Planning Goal 5, environmental overlay zones have been applied to protect rivers, streams, wetlands, tree canopy, steep slopes and wildlife habitat. By 2002, environmental overlay zones had been applied to resources throughout all of Portland. Some areas have been updated since 2002 through district plans like Airport Futures.

In the 1990s, the City’s environmental overlay zones were applied using relatively “low-tech” methods. Today, technology has advanced significantly and can help us identify and better map natural resources. For example, LiDAR is a remote sensing tool that detects light reflected off objects on the ground. LiDAR can be used to accurately and consistently map topography, stream channels, wetlands and vegetation – even the height of individual trees (see Figure 1).

Figure 1: Stream Mapping using LiDAR

Using this new technology, the City updated maps of Portland’s natural resources. Over 160 miles of streams were remapped and approximately 75 miles of previously unmapped streams were added. In 2006, mapping of vegetation patches was updated across the city using new aerial photography. The consistent and replicable approach to mapping natural resource features and functions, was

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documented in the National Resources Inventory (NRI) and adopted by City Council in 2012. The 2035 Comprehensive Plan, adopted in 2018, uses the NRI as a factual basis and directs the city to use the NRI when updating zoning, such as the environmental overlay zones.

The NRI revealed discrepancies between the environmental overlay zone boundaries and the location of resources those overlay zones were intended to protect (see Figure 2). This means the environmental overlay zone boundaries need to be updated. The work is being done by using NRI data, verified through site visits, to show where natural resources are located and adjusting the environmental overlay zone boundaries to match.

Figure 2: Example of an Unprotected Stream Segment

Within Portland there are 12 independent plans that describe the application of environmental overlay zones (see Figure 3); two of those apply to the geography addressed in this report. Each plan was developed at different times, by different staff teams, following changing regulatory and policy conditions and using an evolving methodology and technology. For example, between 1997 and 1999, 12 species of salmon and steelhead were listed under the federal Endangered Species Act (ESA) resulting in changes to local natural resource protection and management. In addition, technological advances between 1991 and 2004 were very significant making the mapping of rivers, streams, wetlands, vegetation and topography much more accurate. The result is that environmental overlay zones are not applied in the same way through each plan.

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Figure 3: City of Portland Conservation and Protection Plans

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The Ezone Map Correction Project uses the policy directions documented in the previously adopted conservation and protection plans and applies those policies to 2012 NRI natural resource feature data. For the Columbia Slough and Columbia River in Portland there are two adopted plans that applied the environmental overlay zones (Map 1): 1. Columbia Corridor Industrial and Environmental Mapping Project (1989) 2. Middle Columbia Corridor/Airport Future Plan (2011)

Map 1: Columbia Slough and Northeast Portland

Each plan included an inventory of natural resources and an Economic, Social, Environmental and Energy (ESEE) analysis as required by State Land Use Planning Goal 5, Natural Resources, Scenic and Historic Areas, and Open Spaces. There was not a consistent or replicable approach or methodology used across the various plans for inventorying the resources or performing the ESEE.

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3 Resource Site Boundaries Within each plan area there are individual resource sites. Delineating resource sites is a required step of Statewide Land Use Planning Goal 5. This project is remapping resource site boundaries to be more consistent and easier to implement.

Past plans did not follow consistent approaches to map resource sites. This often resulted in properties being bisected and different overlay zones being applied to portions of the site even though the resources are the same.

The resource sites were remapped in the following way: 1. The existing resource site boundaries were used to the maximum extent practicable. The intent is to maintain consistency between the past plans and this project. 2. Resource site boundaries were expanded to capture contiguous or similar and adjacent natural resource features. 3. Resource site boundaries were expanded to eliminate unnecessary gaps between resource sites. 4. Very small resource sites, with similar natural resource features and functions, were consolidated into one single larger resource site. 5. Resource site boundaries were adjusted to include entire properties within a single resource site. In some cases, adjacent lots under the same ownership may be in different resource sites; however, in these situations the resource site boundary follows lot lines. 6. Centerlines of streets, bridges, railroad tracks or other transportation facilities are often used to delineate resource site boundaries. 7. The City Boundary or Urban Service Boundary is used along the edges of Portland to provide the outer edge of resource sites.

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4 Natural Resource Descriptions

1. Columbia Corridor Industrial/Environmental Mapping Project (1989) The Industrial/Environmental Mapping Project was adopted in 1989 (Ordinance No. 161895). The final report includes an inventory of natural resource features and the City of Portland’s first Economic, Social, Environmental and Energy (ESEE) analysis. Unlike subsequent projects, the Industrial/Environmental Mapping Project limited the extent of each resource site to 1) water features, or 2) wetlands, riparian areas and uplands. The result was 33 individual resource sites.

This was one of the first conservation planning efforts in Portland and did not use a standardized approach. A high number of assessment variables and methods were applied. The results were reviewed and refined by a technical advisory committee several times before adoption. Experts evaluated each site and assigned a wildlife habitat score ranging from 17 to 106. Smith and Bybee Wetlands and West Hayden Island were the two highest-ranking sites.

Significant Features: • fish habitat • mature cottonwood and willow • riparian forest • uncommon wildlife • Lombardy poplars • open wetland grassland • wetland forest • Johnson Lake • wetlands within the 100-year flood boundary • 50-acre juncus/willow wetland (unusual to Portland)

Significant Functions: • groundwater functions • flood control • fish habitat • pollution nutrient retention • drainage • cover, perch, roost and nesting sites for raptors, woodpeckers, and songbirds • scenic and aesthetic qualities, recreation

4. Middle Columbia Corridor/Airport Futures (2011) The Middle Columbia Corridor/Airport Futures plan used Natural Resource Inventory (NRI) methodology to document natural resources features and assess functions. The inventory includes classification of natural resources in terms of riparian corridor functions and wildlife habitat attributes including Special Habitat Areas. This process started with compiling GIS data, developing scientifically-based criteria to rank and map the relative functions of natural resources and then combining the results to produce an overall relative rank for each resource.

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Significant features: • rivers, streams and drainageways • wetlands and seeps • flood area • forest and woodland vegetation greater than ½ acre in size • shrubland and herbaceous vegetation in the riparian area • wildlife habitat

Significant functions: • microclimate and shade • bank function and control of sediments, nutrients and pollutants • stream flow moderation and flood storage • organic inputs, nutrient cycling and food web • large wood and channel dynamics • wildlife movement corridors • wildlife habitat patch size, interior area and proximity to water

Photo 2: Killdeer in the Columbia Slough Watershed

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5 Summary of ESEE Decisions and Crosswalk to Natural Resource Features

The intent of this mapping protocol is to apply the ESEE decisions and legislative intent1 of the adopted plans to the existing natural resource features by: 1. Comparing the description and mapping of natural resources features in the plans and the current Natural Resources Inventory (NRI) mapped features; and 2. Interpreting the ESEE decisions and legislative intent as it would apply to the current NRI features (explained in Section 6).

Table 1 provides description of each plan’s adopted ESEE decisions and crosswalk to the NRI features.

Table 1: Adopted Generalized ESEE Decisions and Crosswalk to NRI Features Columbia Corridor Industrial/Environmental Mapping Project (1989) Overlay zone Adopted Plan ESEE Decisions Crosswalk to Natural Resource Features protection (p) Large wetlands such as Smith and Wetlands Bybee Wetlands and Ramsey Lake Columbia Slough, associated ditches • Streams and drainageways conservation (c) and drainageways • Land within 50’ of streams and drainageways Small wetlands (see Table 2) Middle Columbia Corridor/Airport Futures (2011) Overlay zone Adopted Plan ESEE Decisions Crosswalk to NRI Port-owned industrial land with • Streams, drainageways and portions of the Columbia Slough, wetlands protection (p) drainageways and wetlands • Land within 50’ of waterbodies Residential land with portions of the • Streams, drainageways and Columbia Slough, drainageways and wetlands wetlands • Land within 50’ of waterbodies Open space land with portions of the • Streams, drainageways and Columbia Slough, drainageways and wetlands wetlands • Land within 50’ of waterbodies Non-Port-owned industrial land with • Streams, drainageways and portions of the Columbia Slough, wetlands conservation (c) drainageways and wetlands • Land within 50’ of waterbodies Columbia River Columbia River and land within 50’ of the river

1 “Legislative intent” means what the adopting body, in this case City Council, intended to do. Legislative intent may be clear, such as stating that protection overlay zones should be applied to streams and land within 50 feet of streams, or more ambiguous, such as saying conservation overlay zones should be applied to all but the highest- ranking resources. When there is ambiguity, staff must interpret the intent.

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Residential land with portions of the Medium ranked riparian resources Columbia Slough, drainageways and wetlands Open space land with portions of the Medium and low ranked riparian Columbia Slough, drainageways and resources wetlands

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6 Environmental Overlay Zone Mapping Protocol To further interpret the adopted ESEE decisions and legislative intent, staff completed the following tasks: 1. The zoning maps adopted with each corresponding plan were analyzed. This led to refinements of the general ESEE decisions and crosswalk to the NRI to better reflect the legislative intent. In some cases, there were large differences between the ESEE decision and the adopted zoning maps.

2. Land use permits approved after adoption of the original zoning maps were reviewed to determine if development or zone changes resulted in modifications to the environmental overlay zone boundaries. This included an in-depth analysis of zoning code violations to make sure the updated zone boundaries do not reward unpermitted removal of natural resources.

3. In 1998 the Environmental Overlay Zone Map Refinement Project adjusted environmental overlay zone boundaries primarily on streams and wetlands; the results were incorporated where appropriate.

4. Finally, existing zoning code requirements are reflected in the mapping. Existing zoning code standards require setbacks from streams and wetlands. Code subsection 33.430.140.C.1 requires that the disturbance area associated with new development or alterations to existing development must be set back at least “fifty (50) feet from the edge of any identified wetland, from the top of bank of any identified water body within the Columbia Corridor ...” In addition, code subsection 33.430.140.F.1 requires that proposed development must be set back the same distance – fifty feet from a wetland or water body in the Columbia Corridor. This setback applies in both the conservation and protection overlay zone. Note - The zoning code reference to the Columbia Corridor is the same geography as the Columbia Slough Watershed.

To more accurately reflect this existing zoning code requirement, this project is proposing that a protection zone (p-zone) rather than a conservation (c-zone) be applied to all water features in the Columbia Slough Watershed. The p-zone would apply below the top-of-bank. The land above top- of-bank will continue to have a conservation (c-zone) or p-zone consistent with the policy decisions of the adopted plans. See Figure 4 which shows an example stream channel and top-of-bank.

Figure 4: Stream Channel

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Map 2: Columbia Slough and Columbia River Resource Sites

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Table 2: Columbia Corridor Industrial/Environmental Mapping Project NRI Crosswalk Resources Site Base Zone Feature Feature Overlay Zone 65, 70 All water Columbia River conservation (c) 65, 70 All water wetlands conservation (c) 45, 50, 60 All water streams/drainageways protection (p) 45, 50, 60 All water wetlands protection (p) 50, 65 All water Water bodies, except Columbia River protection (p) 65, 70 All land land within 50 feet of Columbia River conservation (c) 65, 70 All land land within 50 feet of wetlands conservation (c) 45, 50, 60 IG1, IG2, IH, EG1, EG2 land land within 75 feet of streams/drainageways, except SHA CS7 conservation (c) 45, 50, 60 IG1, IG2, IH, EG1, EG2 land land within 75 feet of wetlands, except SHA CS7 conservation (c) land within 75 feet of water bodies, except the Columbia 45, 50, 60 IG1, IG2, IH, EG1, EG2 land River conservation (c) All, except IG1, IG2, 45, 50, 60 IH, EG1, EG2 land land within 50 feet of streams/drainageways protection (p) All, except IG1, IG2, 45, 50, 60 IH, EG1, EG2 land land within 50 feet of wetlands protection (p) All, except IG1, IG2, land within 50 feet of water bodies, except the Columbia 45, 50, 60 IH, EG1, EG2 land River protection (p) All, except IG1, IG2, 45, 50, 60 IH, EG1, EG2 land land within 25 feet of p-zone conservation (c) Forest and woodland vegetation contiguous to but more than 45, 60 All vegetation 75 feet from all streams/drainageways, except SHA CS7 conservation (c) Forest and woodland vegetation contiguous to and more 45 All vegetation than 75 feet from wetlands, except SHA CS7 conservation (c) 45 All land All land within Columbia Childrens Arboretum conservation (c) 60 All SHA All remaining land in SHA CS3 conservation (c) 60 All SHA All remaining land in SHA CS4 conservation (c) 50 All SHA All land in SHA CS7 protection (p) 50 All SHA All remaining land in SHA CS8 conservation (c)

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Table 3: Middle Columbia Corridor/Airport Futures NRI Crosswalk Port Owned Properties Resources Site Base Zone Feature Feature Overlay Zone CS1, CS4a, CS4b, CS5b All water Streams/drainageway protection (p) CS1, CS4a, CS4b, CS5b All water Wetlands protection (p) CS1, CS4a, CS4b, CS5b All land Land within 50 feet of stream/drainageway protection (p) CS1, CS4a, CS4b, CS5b All land Land within 50 feet of wetland protection (p) CS5a All water Streams/drainageway conservation (c) CS5a All water Wetlands conservation (c) CS5a All land land within 50 feet of Streams/drainageway conservation (c) CS5a All land land within 50 feet of wetlands conservation (c) CS3 All water River conservation (c) CS3 All land Land within 50 feet of river conservation (c) CS1 All SHA SHA 13 protection (p) In SHA CS21, all land that is more than 50 feet from a stream CS1 All SHA or wetland conservation (c) CS1 All SHA Land within 50 feet of SHA 13 conservation (c) CS1, CS4a, CS5a, CS5b All land land within 25 feet of c- or p-zones conservation (c) Not Port Owned Properties Resources Site Base Zone Feature Feature Overlay Zone CS1, CS4a, CS4b All water Streams/drainageway protection (p) CS1, CS4a, CS4b All water Wetlands protection (p) CS3 All water River conservation (c) CS3 All land Land within 50 feet of river conservation (c) CS1, CS4a IH, IG1, IG2, EG1, EG2 land land within 50 feet of Streams/drainageway conservation (c) CS1, CS4a IH, IG1, IG2, EG1, EG2 land land within 50 feet of wetlands conservation (c) 15 Public Review DRAFT June 2019

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CS4b IH, IG1, IG2, EG1, EG2 land Land within 50 feet of stream/drainageway protection (p) CS4b IH, IG1, IG2, EG1, EG2 land Land within 50 feet of wetland protection (p) All, except IH, IG1, CS1, CS4a, CS4b IG2, EG1, EG2 land Land within 50 feet of stream/drainageway protection (p) All, except IH, IG1, CS1, CS4a, CS4b IG2, EG1, EG2 land Land within 50 feet of wetland protection (p) High ranked riparian resources more than 50 feet from CS1, CS4a, CS4b Residential zones, OS high rank stream/drainageway or wetland protection (p) medium Medium ranked riparian resources more than 50 feet and up CS1, CS4a, CS4b Residential zones rank to 300 feet of a stream/drainageway or wetland conservation (c) medium and low Medium and low ranked riparian resources more than 50 feet CS1, CS4a, CS4b OS rank and up to 300 feet of a stream/drainageway or wetland conservation (c) In SHA CS21, all land that is more than 50 feet from a stream CS1 All SHA or wetland conservation (c) CS1 All SHA SHA CS13 protection (p) CS1 All SHA Land within 50 feet of SHA CS13 conservation (c) CS1, CS4a All land land within 25 feet of c- or p-zones conservation (c) Note – The natural resources in Resources Site CS6, although part of the Middle Columbia Corridor/Airport Futures Plan, is regulated by the Columbia South Shore Plan District and therefor not part of this project.

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