Creswell's Flood Risk

Creswell experienced frequent flooding before Congress authorized the construction of Cottage Grove Dam and Dorena Dam by the US Army Corps of Engineers as part of the Willamette Valley Flood Control Project in 1936. Although the construction of the Cottage Grove and Dorena Dams between 1942-1945 greatly reduced the frequency of flooding in our community, the risk still exists.

The last “big” flood we saw on both rivers at the same time was in December of 1964, when we had what was equivalent to an 80-year flood. Dorena and Cottage Grove Dams saw peak discharges twice their normal averages that December. In December 1996 and February 1997, so much water filled the Dorena Reservoir that it washed over the top of the Dam, in what is now considered a 20-year flood. Silk Creek last flooded over its banks during the flood of 1997.

EXISTING FIRM MAPS (1999):

In 1999, Creswell adopted new Flood Insurance Rate Maps provided by FEMA – these are the existing FIRM maps that we have been using to determine properties within the “100 year floodplain” or “Special Flood Hazard Area”. These maps were based upon aerial photographs of the 1996 floods.

CENTRAL LANE COUNTY (RE)MAPPING PROJECT (2020):

Flood risk changes over time, and mapping technology has improved. By working with the state, county and local communities, FEMA is using updated data and newer technology to update the flood maps. Updated maps will more accurately represent the risk of flooding in your community.

The new map can help Creswell residents better understand flood risks. This leads to more informed decisions about how to guard against damage and loss.

WHAT DOES THIS MEAN FOR ME?

The new flood map, officially known as a Flood Insurance Rate Map, identifies areas of flood risk (high, moderate, low).  It will influence financial, planning, investment and development decisions.  Owners of structures in high-risk areas will be required to have flood insurance for loans from federally regulated or insured lenders. We encourage everyone to be aware of their flood risk and purchase flood insurance.

The revised map is available online for public review and comment. The appeal period is open until April 19th, 2023. Any appeals, questions, or concerns should be directed to Curtis Thomas at cthomas@creswell-or.us or at 541-895-2531. 

More information about the flood map update can be found here:

Central Lane County FEMA Flood Map Update Information

You can view the maps here:

Lane County, Oregon (Coast Fork and Middle Fork Willamette River) - Flood Map Comparison (Effective vs. Revised Preliminary)

Creswell Development Code Requirements for Flood Damage Prevention:

Creswell Development Code Chapter 2.7 Floodplain Overlay Zone requires Floodplain Development Permits for all new development (including fill, grading, excavation, new accessory structures, new houses, additions or alterations to existing structures, fences, etc.) for properties in the Special Flood Hazard Area (SFHA). This includes any properties identified as part of the AE, A, or AO zones, or in a designated Floodway.

If you are one of those properties impacted by the SFHA by the current or new FIRM Map, you will need to learn this code. (See below for a link to the Development Code.)

Floodplain Development Permits are issued by the Planning Department prior to or as part of building permit applications. If you are thinking of building anything on your property, or want to talk about ideas you have for development in an area identified as part of a floodplain, please contact our office prior to starting any work and we’ll walk you through the permit process.

For additional information on local floodplain regulations, please contact our partner Floodplain Administrator, Eric Mongan, planner@cottagegrove.org, (541) 942-3340.

Flood Information:

We have a robust library with flood information, which includes printed and video resources that will help you mitigate your risk if you live in a flood area. One of the goals of the Planning Department is to provide information to the public on flood preparation and flood damage prevention. Below are links to various resources including some provided by the City's website and some provided by outside sources. Along with these, attached at the bottom is a FEMA pamphlet Repairing Your Flooded Home, and the US Army Corps of Engineers booklet Local Flood Proofing Programs.

Coast Fork of the Willamette River Gauge

In order to find real-time information on the Willamette River temperature, water levels, discharge, and more click here to visit the USGS Willamette River Water Gage.

US Army Corps of Engineers TEACUPS
Real time information on the water levels of the lakes within the Willamette Valley as well as information on bank levels and flood stages as provided by the US Army Corps of Engineers

CITY PROVIDED RESOURCES

Floodplain Overlay Zone Code Section 2.7
Chapter from the Creswell Development Code applicable to properties in the "100-year" Floodplain and Floodway.

Flood Definitions: See Environmental-Related Definitions 
Definitions and Standards regarding flooding taken from the Creswell Development Code.

Emergency Preparedness Videos
Videos providing information on emergency preparedness and personal safety created by our partners at the City of Cottage Grove Planning Division.

About the Mandatory Purchase of Flood Insurance
Description on the NFIP and information on when Flood Insurance is mandatory.

Natural Hazards Mitigation
Creswell's annex to the Lane County Multi-Jurisdiction Natural Hazards Mitigation Plan and brief descriptions of potential natural hazards.

Creswell's Floodplain Map Comparison
Map of Creswell including Floodway and "100-year" Floodplain.

Floodplain Development Permit Application (see files, below)

February 1996 Flood video footage (provided by Ed Gunderson)

FEMA HOW TO PREPARE FOR A FLOOD

US Army Corps of Engineers Water Safety Tips

Coast Fork Willamette Watershed Council Science Pub

NATIONAL FLOOD INSURANCE PROGRAM

National Flood Insurance Program
The official website for the National Flood Insurance Program courtesy of FEMA.

Flood Insurance Rate Maps
Flood Insurance Rate Maps (FIRMs) for the City of Creswell as well as a link to the FEMA FIRM website.

OTHER RESOURCES

Oregon Office of Emergency Management
Information on natural hazards and preparedness for the State of Oregon as provided by the Oregon Office of Emergency Management.

FEMA Home Page
The main website for FEMA from which information on emergency preparedness, flooding, flood insurance, and more can be found.

US Army Corps of Engineers Willamette Valley Project
Information on the Willamette Valley Project which oversees both the Cottage Grove Lake and Dorena Lake.

Ready.gov Flood Information
Basic information on flood preparation and flood safety as provided by Ready.gov.

American Red Cross Flood Safety
Basic information on flood preparation and flood safety as provided by American Red Cross.

National Weather Service Creswell Information​
Real time update on climate and weather for the City of Creswell as provided by The National Weather Service.

• Floodplain Overlay Zone Development Application