Working for over 15 years through the Willing Seller Acquisition Program, the City of Portland purchased the land from 60 families and helped them move out of the 100-year floodplain.
Natural area wildlife
The project's innovative design takes a natural approach to reducing local flood risks that also improves fish and wildlife habitat along Johnson Creek. The project restored over a half mile of the creek for native salmon, trout and lamprey.
Pond and wetland enhancements benefit sensitive frogs and salamanders. Hidden in the grasses and shrubs are ground-nesting birds like killdeer and small mammals, including rabbits and skunk. Deer, coyote, hawks and bald eagles also use the site. The restored floodplain also improves the water quality of Johnson Creek by allowing sediments in high water to settle onto the floodplain.
Project funding
Because of the project’s many community and environmental benefits, the Federal Emergency Management Agency (FEMA) granted the City of Portland $2.7 million through the Pre-disaster Mitigation Grant Program to help fund the project. Other funding came from federal community block grants and Portland stormwater funds.
Restoration of the site helps achieve goals of the Portland Watershed Management Plan and the Johnson Creek Restoration Plan, which calls for improving water quality, enhancing habitat, and preventing damage from floods that occur about every 10 years or more frequently. It also supports Portland Parks & Recreation’s Natural Area Acquisition Strategy.
Flood mitigation
- Added 140 acre-feet of flood storage (enough to cover the site with about one and a half feet of water)
- Removed three bridges and three roads (at SE 106th, 108th 110th avenues) to allow flood waters to access the restored floodplain
- Removed 50,000 cubic yards of soil and other material
- Reduced the risk of flooding on Foster Road to about one-third the previous rate (historically, Foster Road flooded in this area about every other year - with the enhanced floodplain, flooding will be reduced to about every 6-8 years)
Habitat enhancement
- Restored 63 acres of wetland and floodplain habitat
- Restored over a half mile of Johnson Creek for fish and wildlife, including threatened coho and Chinook salmon, and steelhead trout by removing rock armoring the Works Progress Administration placed in the creek in the 1930s in an unsuccessful attempt to reduce flooding
- Added over 200 pieces of large wood for habitat into the creek bank
- Created two backwater channels to provided resting places for fish during high flows
- Enhanced two ponds as habitat for sensitive red-legged frogs and Northwestern salamanders
- Re-used downed trees in brush piles for upland habitat
- Planted:
- 20,500 native trees
- 70,500 native shrubs
- 4,750 of wetland plants
- 1,000 pounds of native grasses, sedges, and forbs
Neighborhood improvement
- Created a publicly-accessible natural area in east Portland
- Added an ADA-accessible trail and pedestrian bridge to view Johnson Creek and wildlife
- Built a parking area that also serves as a trailhead for the Springwater Corridor Trail
- Created an interpretive kiosk
- Installed sidewalks, street trees and stormwater swales along Foster Road and SE 112th Avenue
Project effectiveness tested by flooding
- 2012 storm: Heavy rains in January 2012 pushed Johnson Creek to more than two feet above historic flood stage and filled the restoration site with water. In the past, Johnson Creek would have flooded Foster Road, but the restored floodplain held the high water, kept Foster Road dry, and helped local businesses stay open. This relatively typical flood event for Johnson Creek demonstrated that Foster Floodplain is working as intended to handle the creek’s more frequent floods.
- 2015 storm: An intense 25-year rain storm in December 2015 caused Johnson Creek to rise to a height of 15.33 feet, breaking all previous records since monitoring the creek began in 1941. While the December 2015 flood was a historic high for the creek, flood water covered less area along Foster Road and in nearby neighborhoods than during earlier storms, including the November 1996 flood of record.
- Foster Floodplain and other nearby restoration projects haven’t “fixed” the 100-year flood on Johnson Creek, they are helping reduce impacts to the community during both small and large floods.
Visiting the site
Find more information about visiting the Foster Floodplain Natural Area.