Floodplain assessment

We are available to provide flood-related data and visit sites to review flood, drainage and sewer problems. We can advise and assist on possible alternatives that may help reduce flood risk.

Please call us at 503-742-4500 for assistance.

County rivers

Clackamas County contains rivers and streams that are susceptible to flooding. These floods can pose a threat to life and safety, and cause significant property damage.

Large county rivers include the Clackamas, Tualatin, Molalla / Pudding, Salmon, Sandy, Willamette and Zig Zag. County streams include Johnson Creek, Abernethy Creek, Beavercreek, Milk Creek and Cedar Creek.


We have had several significant recent floods, such as the Sandy River flood of January 2011. In 1996, a warm-weather system known as a "Pineapple Express" caused many rivers and creeks throughout the region to rise to 100-year flood levels.

Although the floods of 1996 represented a large-scale disaster, they are not unprecedented within the recent past. The Christmas Flood of 1964 caused $157 million in damage, and 20 Oregonians lost their lives. Records dating back to the mid-1800s show at least seven significant Willamette River floods in the county. Flooding from the Clackamas River has dramatically affected the county at least five times.

Flood insurance

Clackamas County participates in the National Flood Insurance Program (NFIP), which provides federally-backed flood insurance. This insurance is available for all structures, whether or not they are in the floodplain.

As part of the program, the county must manage its floodplain in ways that meet or exceed standards set by the Federal Emergency Management Agency (FEMA). Federal financial assistance requires flood insurance for buildings located within the SFHA (Special Flood Hazard Area). This requirement affects almost all mortgages financed through commercial lending institutions.

While the insurance requirement has existed for many years, not all lending institutions required flood insurance in the past. Today, however, most institutions do require flood insurance. Some are reviewing all mortgage loans to determine whether flood insurance is required and should have been required in the past.

For more information, contact FEMA or call your local insurance agent.

About floodplains

Floodplain development materials


Flood Smart