About the Floodplain Resilience Plan

Purpose, background, steps and timeline about the Floodplain Resilience Plan.

Project purpose

The purpose of the Floodplain Resilience Plan is to reduce the impacts of future flooding and the degradation of floodplain habitat on endangered and threatened fish species. In anticipation of new Federal Emergency Management Agency (FEMA) guidelines, the project will:

  • Update the rules for new development along the edges of Portland’s rivers and streams.
  • Strengthen protections for the wildlife for which it is home.

The Floodplain Resilience Plan includes a number of updates to the Zoning Code, so the Bureau of Planning and Sustainability (BPS) is leading this effort, in partnership with the Bureaus of Environmental Services and Development Services. The project will:

  • Incorporate the results of a U.S. Army Corps of Engineers model for the Lower Willamette River into the City’s regulated floodplains to better address future flood risk. This flood extent, known as the Modeled Willamette River 1996 Flood Extent, will be included in the City’s “combined flood hazard area,” along with the FEMA 100-year floodplain and the existing 1996 Flood Inundation Area (as defined by Metro) outside the Modeled Willamette River 1996 Flood Extent. (The BDS building code project described below will also make updates using this new flood map.)
  • Update land use requirements for the combined flood hazard area in many parts of the city.
  • Apply additional mitigation requirements to increase habitat within 170 ft of rivers.
  • Ensure that undeveloped floodplains are within one of City’s environmental overlay zone.
  • Establish new minimum mitigation requirements for impacts to floodplain habitat, including trees and other vegetation.

The Bureau of Development Services is leading a parallel project to update the building code (Title 24, Chapter 24.50, Flood Hazard Areas) so future development still conveys flood waters away from development when the project includes adding soil and/or structures in the floodplain. This project will include updates to the amount of compensatory excavation (or “cut”) required to offset any expected reduction in floodwater conveyance.

An initial draft of these proposed changes was included in the Floodplain Resilience Plan Discussion Draft. However, because building code changes are not subject to the City’s legislative process and the Planning and Sustainability Commission does not oversee the building code, a separate BDS-led project, including additional opportunities for public input, is expected to move forward in the coming months.

A companion restoration program led by the Bureau of Environmental Services (BES) aims to improve habitat for threatened and endangered species through the acquisition and restoration of sites in key floodplain areas. Without these and future projects, Portlanders risk losing access to federally backed flood insurance and disaster relief grants available to communities that participate in FEMA’s National Flood Insurance Program (NFIP).

Project background

The City of Portland is situated at the confluence of the Columbia and Willamette rivers. Several tributaries feed the Willamette River, including important fish-bearing streams, such as Johnson Creek, Tryon Creek and Fanno Creek (via the Tualatin River). Salmon and steelhead that live, grow in, and travel through these Portland waterways eventually find their way to many parts of the Pacific Northwest and the ocean.

Salmon have been an integral part of the Pacific Northwest ecosystem for thousands of years, but loss of habitat, water pollution, and barriers such as dams and culverts have reduced their numbers by approximately 90% from historic estimates. Salmon and steelhead are culturally significant species to the area’s many Native American tribes. The health and abundance of these iconic species are also essential to northwest economies, including commercial and sport fisheries as well as outdoor recreation.

The City of Portland is committed to helping protect and contribute to the recovery of 13 endangered and threatened salmon and steelhead populations – more species than any other city on the west coast. Adoption of City Resolutions 35715 (1998) and 35894 (2000) demonstrate Portland’s commitment to the recovery of listed salmon and steelhead within its jurisdiction. Over the past 20 years, Portland has made significant investments to support the return of wild salmon to its 125 miles of rivers and streams.

View the project overview document:

The Biological Opinion

In 2009, several local and national environmental and fish conservation organizations, including Portland Audubon, sued FEMA, claiming that implementation of the NFIP in Oregon jeopardizes the recovery of threatened and endangered salmon and steelhead. As a result of the lawsuit, FEMA agreed to have the National Marine Fisheries Service (NMFS) assess the program in Oregon to determine its potential impacts on Endangered Species Act (ESA)-listed species.

In April 2016, NMFS released its Biological Opinion (FEMA BiOp), which stated that FEMA’s implementation of the NFIP in Oregon jeopardizes protected salmon and steelhead because it results in floodplain development and, therefore, a reduction in habitat for these protected species. The FEMA BiOp went on to recommend that FEMA require NFIP participants to develop regulations and programs to ensure they adequately protect floodplain habitat and flood storage. FEMA has been, and continues, working with Oregon jurisdictions to develop regulations and programs that respond to the FEMA BiOp and recognize Oregon land use law and local conditions.

Implementation of ESA-compliant development regulations, along with City-led restoration projects, will help ensure Portlanders have ongoing access to the federally backed flood insurance they rely on to meet their mortgage requirements and access financial assistance for flood recovery.

More on the National Flood Insurance Program (NFIP)

Created by Congress in 1968, the NFIP offers federally backed insurance to homeowners, renters, and business owners if their local government participates in the program. Flood insurance is required for all federally backed mortgages and loans in federally designated flood zones, called Special Flood Hazard Areas. Federal flood insurance is available, regardless of risk and often (but not always) at a lower cost than private insurance. Frequently, it is available when private insurance is not.

Participation in the NFIP requires that communities implement FEMA’s minimum requirements. Current requirements include building and site development standards for properties in the floodplain and compliance with applicable federal laws, including the ESA.

NFIP-participating communities can also help lower insurance rates for residents through participation in FEMA’s voluntary Community Rating System (CRS) program, which incentivizes community flood mitigation and preparation. Today, Portland’s mitigation and preparation programs result in a 20% discount for Portlanders. This is a significant discount, but it can be lowered even more to a federal maximum discount of 50% through increased preparation and mitigation programs, such as this Floodplain Resilience Program.

Project steps and timeline

Summer 2021: Intergovernmental review

November 2021: Release of public Discussion Draft

November 2021 – January 2022: Public/property owner engagement

August 30, 2022: Release of Proposed Draft

September 13, 2022: Planning and Sustainability Commission (PSC) briefing

September 27, 2022: PSC public hearing

October – November 2022: PSC work sessions and recommendation

Spring 2023: City Council public hearing(s), deliberations and decision