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Portland, Oregon FEMA Floodplain

City of Portland, Oregon
  • Added 24 Oct 2018
  • Updated 04 Jul 2019
  • 101 Views
  • 0 Downloads

The National Flood Hazard Layer (NFHL) data incorporates all Flood Insurance Rate Map (FIRM) databases published by the Federal Emergency Management Agency (FEMA), and any Letters of Map Revision (LOMRs) that have been issued against those databases since their publication date. It is updated on a monthly basis. The FIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper FIRMs. The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk.

--Additional Information:
Category: Hazard
Purpose: The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards, " Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The FIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The FIRM Database serves to archive the information collected during the Flood Risk Project.
Update Frequency: As needed

© Bureau of Planning and Sustainability

Information

RegionsClackamas County, Multnomah County, Washington County

Technical Details

Layer ID 98605
Data type Vector multipolygon
Feature count 7642
Attributes STUDY_TYP, STATIC_BFE, SFHA_TF, DEPTH, DFIRM_ID, LEN_UNIT, VEL_UNIT, SHAPE_Length, ZONE_SUBTY, SOURCE_CIT, VELOCITY, DEP_REVERT, AR_REVERT, FLD_AR_ID, DUAL_ZONE, FLD_ZONE, AR_SUBTRV, V_DATUM, VERSION_ID, BFE_REVERT
Services Vector Query API

History

Added24 Oct 2018
Last updated4 Jul 2019
Revisions 2 - Browse all revisions
Current revision Imported on July 3, 2019 from Esri JSON in WGS 84 / Pseudo-Mercator. 38 geometries modified to be OGC compliant. Changelog.
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