Description: This layer was created to assist in coordinating development review in the Columbia Corridor to ensure the integrity of the flood management system is not compromised by development. MCDD must review development for possible threats to the system. This GIS layer includes the levees in the four Districts managed by MCDD.
--Additional Information:
Category: Boundary
Purpose: This layer depicts the, “Levee Review Area” which is the area in which MCDD must review development and public works projects to ensure compliance with federal levee safety standards. We hope this data sharing will help us all achieve compliance with ORS 195 for levee and stormwater impact reviews.
Update Frequency: As-Needed
Description: Areas identified by the Federal Emergency Management Agency (FEMA) as having a 1% annual chance of flooding. Known as the "Special Flood Hazard Area" (SFHA), which is also commonly referred to as the 100-year floodplain. Based on November 2010 FEMA maps, with subsequent "Letters of Map Revision" (LOMR) information incorporated as approved by FEMA.
Description: Areas identified by the Federal Emergency Management Agency (FEMA) as having a 0.2% annual chance of flooding, which is also commonly referred to as the 500-year floodplain. Based on November 2010 FEMA maps, with subsequent "Letters of Map Revision" (LOMR) information incorporated as approved by FEMA.
Description: A record peak flow in February of 1996 caused the Willamette River and its major tributaries to flood. This map was created to delineate the inundated areas near the mainstem and major tributaries of the Willamette River.
Description: Points representing trunk locations of Heritage Trees of Portland.
--Additional Information:
Category: Environmental
Purpose: The Heritage Tree ordinance calls for the City Forester to annually prepare a list of trees that - because of their age, size, type, historical association or horticultural value - are of special importance to the City
Update Frequency: Annually
Description: The intent of this dataset is to depict landslide deformation from a M9 earthquake on the Cascade Subduction Zone within the Portland Water Bureau (PWB) service area and corridors along the conduits leading from the Bull Run watershed.
Evaluating the potential for liquefaction and employing methods to mitigate its impacts were recognized as key factors for increasing earthquake resilience in the Oregon Resilience Plan (OSSPAC, 2013), as well as previous earthquake risk studies. Delineation of liquefaction-susceptible deposits in the PWB service area and estimating the magnitude of potential ground deformation is essential for the evaluation of potential damage from future large earthquakes in the Portland area. Mapping of liquefaction hazard allows for planning and mitigation prior to the next large earthquake and can be used for prioritizing emergency response following the earthquake.
This dataset represents landslide deformation for the City of Portland Water Bureau service area and the conduit corridors leading from the Bull Run Watershed. Data are classified into ranges. Water bodies were removed. Complete methodology for landslide deformation can be found in the accompanying memorandum report for the "Portland Water Bureau Water System Seismic Study: Landslide Deformation for M9.0 Cascadia Earthquake Map," version 2.0, 2016.
Copyright Text: InfraTerra Inc. and Cascade GIS & Consulting LLC.
Description: The regulatory landslide hazard area map was created from three sources: Areas identified and mapped by Oregon Metro as earthquake hazard areas, areas delineated as zones of high landslide potential in a study conducted by Portland State University based on the mapping of more than 676 landslide events that occurred as a result of the February 1996 storms, and all land within the City that has a slope of 15 percent or greater.
Description: Polygons representing slopes greater than or equal to 20% in the Portland urban services boundary area. Derived from 2014 3' resolution LiDAR bare-earth digital elevation model (DEM). All slopes average over a horizontal distance of 15'. Minimum area of contiguous slope is approximately 1/2 acre. Polygons were created, generalized and smoothed in ArcGIS 10.3.1.
Description: Regional stream centerline dataset. Reference sources include 2004 through 2007 LiDAR data, aerial photos, and the mapped stormwater collection system.
This data can be viewed online at www.PortlandMaps.com.
--Additional Information:
Category: Hydro
Purpose: For mapping the location of stream centerlines.
Update Frequency: As needed
Copyright Text: Bureau of Planning and Sustainability
SUBAREA
(
type: esriFieldTypeString, alias: SUBAREA, length: 30
, Coded Values:
[City of Portland: City of Portland]
, [City of Gresham: City of Gresham]
, [Clean Water Services: Clean Water Services]
, ...2 more...
)
Description: National Wetland Inventory (NWI) with revisions made by local governments in the tri-county region. Portland wetlands are updated from the original Metro dataset by City of Portland, Bureau of Planning & Sustainability to refine geometry, remove erroneously mapped wetlands, and add missing wetlands.
This data can be viewed online at www.PortlandMaps.com.
--Additional Information:
Category: Hydro
Purpose: For identifying the location of wetlands.
Update Frequency: As needed
Copyright Text: Bureau of Planning and Sustainability
Description: National Wetland Inventory (NWI) with revisions made by local governments in the tri-county region. Portland wetlands are updated from the original Metro dataset by City of Portland, Bureau of Planning & Sustainability to refine geometry, remove erroneously mapped wetlands, and add missing wetlands.
This data can be viewed online at www.PortlandMaps.com.
--Additional Information:
Category: Hydro
Purpose: For identifying the location of wetlands.
Update Frequency: As needed
Copyright Text: Bureau of Planning and Sustainability
Description: Regional streams, rivers, lakes, ponds and other surface water features. Only features large enough to be visible on aerial photographs or delineated from LiDAR data are mapped (more detailed stream information is available as centerlines).
This data can be viewed online at www.PortlandMaps.com.
--Additional Information:
Category: Hydro
Purpose: For identifying the location of streams and waterbodies.
Update Frequency: Continually
Copyright Text: Bureau of Planning and Sustainability
SUBAREA
(
type: esriFieldTypeString, alias: Maintaining Agency, length: 30
, Coded Values:
[City of Portland: City of Portland]
, [City of Gresham: City of Gresham]
, [Clean Water Services: Clean Water Services]
, ...2 more...
)
Description: Regional stream centerline dataset. Reference sources include 2004 through 2007 LiDAR data, aerial photos, and the mapped stormwater collection system.
This data can be viewed online at www.PortlandMaps.com.
--Additional Information:
Category: Hydro
Purpose: For mapping the location of stream centerlines.
Update Frequency: As needed
Copyright Text: Bureau of Planning and Sustainability
SUBAREA
(
type: esriFieldTypeString, alias: SUBAREA, length: 30
, Coded Values:
[City of Portland: City of Portland]
, [City of Gresham: City of Gresham]
, [Clean Water Services: Clean Water Services]
, ...2 more...
)
Description: This data set represents the extent, approximate location and type of wetlands and deepwater habitats in the United States and its Territories. These data delineate the areal extent of wetlands and surface waters as defined by Cowardin et al. (1979). The National Wetlands Inventory - Version 2, Surface Waters and Wetlands Inventory was derived by retaining the wetland and deepwater polygons that compose the NWI digital wetlands spatial data layer and reintroducing any linear wetland or surface water features that were orphaned from the original NWI hard copy maps by converting them to narrow polygonal features. Additionally, the data are supplemented with hydrography data, buffered to become polygonal features, as a secondary source for any single-line stream features not mapped by the NWI and to complete segmented connections. Wetland mapping conducted in WA, OR, CA, NV and ID after 2012 and most other projects mapped after 2015 were mapped to include all surface water features and are not derived data. The linear hydrography dataset used to derive Version 2 was the U.S. Geological Survey''''''''s National Hydrography Dataset (NHD). Specific information on the NHD version used to derive Version 2 and where Version 2 was mapped can be found in the ''''''''comments'''''''' field of the Wetlands_Project_Metadata feature class. https://www.fws.gov/wetlands/Data/metadata/FWS_Wetlands.xml Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats include seagrasses or submerged aquatic vegetation that are found in the intertidal and subtidal zones of estuaries and near shore coastal waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been excluded from the inventory. These habitats, because of their depth, go undetected by aerial imagery. By policy, the Service also excludes certain types of "farmed wetlands" as may be defined by the Food Security Act or that do not coincide with the Cowardin et al. definition. Contact the Service''''''''s Regional Wetland Coordinator for additional information on what types of farmed wetlands are included on wetland maps. This dataset should be used in conjunction with the Wetlands_Project_Metadata layer, which contains project specific wetlands mapping procedures and information on dates, scales and emulsion of imagery used to map the wetlands within specific project boundaries.
Description: This layer replicates DSL's NHD Area layer for the SWI. DSL describes the layer as the following: For the purpose of the Statewide Wetlands Inventory, DSL has filtered the NHD Area data to not display polygons identified as "Area to be Submerged", "Bridge", DamWeir", and "Levee" features, FType codes of "307", "318", "343" and "568" respectively. This data can be found at https://www.usgs.gov/core-science-systems/ngp/national-hydrography/access-national-hydrography-products.
Copyright Text: Prepared by the Portland Bureau of Environmental Services Wetland Inventory Project using USGS NHD data accessed on January 14, 2020. https://www.usgs.gov/core-science-systems/ngp/national-hydrography/access-national-hydrography-products. See dataset specific metadata for original credits.
Description: This layer replicates DSL's NHD Streams and Rivers layer for the SWI. DSL describes the layer as the following: For the purpose of the Statewide Wetlands Inventory, DSL has filtered the NHD Line data to display only the Stream/River and Canal/Ditch line features, FType codes equal to "336" and "460". This data can be found at https://www.usgs.gov/core-science-systems/ngp/national-hydrography/access-national-hydrography-products.
Copyright Text: Prepared by the Portland Bureau of Environmental Services Wetland Inventory Project using USGS NHD data accessed on January 14, 2020. https://www.usgs.gov/core-science-systems/ngp/national-hydrography/access-national-hydrography-products. See dataset specific metadata for original credits.
Description: This layer replicates DSL's NHD Waterbody layer for the SWI. DSL describes the layer as the following: For the purpose of the Statewide Wetlands Inventory, DSL has filtered the NHD Waterbody data to not display polygons identified as "Ice Mass" features, FType code of "378". This data can be found at https://www.usgs.gov/core-science-systems/ngp/national-hydrography/access-national-hydrography-products.
Copyright Text: Prepared by the Portland Bureau of Environmental Services Wetland Inventory Project using USGS NHD data accessed on January 14, 2020. https://www.usgs.gov/core-science-systems/ngp/national-hydrography/access-national-hydrography-products. See dataset specific metadata for original credits.
Description: NRCS Predominantly Hydric Soil Map Units prepared from USDA NRCS SSURGO data. Extent of mapping is limited to the Portland Urban Services Area and West Hayden Island. The Portland Urban Services Area includes portions of Multnomah, Clackamas, and Washington Counties. The Predominantly Hydric Soil Map Units layer dsiplays all map units where "Percent Hydric" (HydrcRatng) entry is greater than 50 percent. This shows map units with over 50 percent soil components meeting NRCS hydric soil criteria. These areas do not show where wetlands are, but where most soil components tend to be saturated, inundated, or flooded for long periods of time, thus increasing the potential that wetlands may develop in these areas. This layer is provided as a screening tool for those areas where wetland mapping may be lacking, incomplete, or inaccurate. In all cases actual field conditions determine the presence and extent of wetlands.
Copyright Text: Prepared by the Portland Bureau of Environmental Services Wetland Inventory Project using USDA NRCS SSURGO data accessed on January 13, 2020.