Lower Willamette River Floodplain – State Wildlife Action Plan

Willamette Falls — Photo Credit: Bernadette Graham-Hudson, ODFW

The Lower Willamette River Floodplain COA (17 mi²) extends along the mainstem Willamette River from the confluence with the Columbia River upstream to Willamette Falls in Oregon City (river miles 0 to 26). This COA includes the river’s floodplain and adjacent uplands. This COA is adjacent to the Sauvie Island – Scappoose, Forest Park, Smith-Bybee Lakes and Columbia Slough, Clackamas River and Tributaries, and Middle Willamette River Floodplain COAs.

Recommended Conservation Actions

Improve aquatic and riparian habitat complexity and diversity.
Improve riparian buffers.
Maintain and enhance isolated wetlands to provide habitat for amphibians and turtles.
Maintain and expand Oregon white oak habitat.
Protect and improve water quality.
Protect and restore shallow water and off-channel habitats.
Remove fish and wildlife passage barriers.
Restore floodplain function and connectivity.
Restore riparian and wetland plant communities.

Local Conservation Actions and Plans

Special Features

General

The Willamette River provides an important movement corridor for migratory and resident fish and wildlife.
Restoration of the Lower Willamette River and the associated floodplain and uplands has had important implications for fish and wildlife habitat in this COA. These restoration efforts have had social and economic benefits as well, resulting from restored ecological functions (e.g., improved flood control and water quality).
This area includes numerous important habitat sites for fish and wildlife, including Oaks Bottom Wildlife Refuge and the confluence with the Clackamas River. The COA also includes many riverine islands – Ross Island, Elk Rock Island, Rock Island, Cedar Island, and Clackamette Island among them.
This COA is located in an extremely urban area, running right through the center of the Portland metropolitan area. This area also includes the Portland Harbor Superfund site, which runs down ~10 river miles of the Willamette River. In recent years there have been nearly annual harmful algal blooms emanating from the Ross Island Lagoon, though there have been recent efforts to better understand and control these events. The river banks through this section are also covered with many small private docks, adding to the urbanization of this COA.
The Portland Bureau of Environmental Services and North Clackamas Watershed Council, along with other partners, have been involved in many recent major floodplain restoration projects in this area. This includes multiple restoration projects at the tributary junctions of small streams with the Willamette River from Johnson Creek to Abernethy Creek, and the dam removal project on Kellogg Creek.

Protected Areas

Bell View Point
Bluff above Swan Island
Butterfly Park
Camassia Preserve
Cathedral Park
Cedar Island
Cedaroak Boat Ramp
Clackamette Park
Cottonwood Bay
Dahl Beach
Dogwood Park
Elk Rock Island
Foothills Park
Forest Park
George Rogers Park
Glenmorrie Greenway
Goat Island
Gov. Tom McCall Waterfront Park
Harbor View Property
Holgate Slough
Japanese American Historical Plaza
Johns Community Garden
Jon Storm Park
Kelley Point Park
Kincaid Curlicue Corridor
Kingsley Park
Linnton Park
Maddax Woods
Mary S. Young State Recreation Area
McCarthy Park
McLean House
McLoughlin House
McLoughlin Promenade
Meldrum Bar Park
Mill Ends Park
Milwaukie Riverfront Park Property
Oaks Bottom Wildlife Refuge
Old Canemah Park
Oswego Creek Outlet Access Willamette River Greenway
Peter Kerr Property
Portland Classical Chinese Garden
Powers Marine Park
River Cover Open Space
Rivervilla Park
Robinwood Open Space
Rocky Island Park
Roehr Park
Ross Island Natural Area
Sellwood Riverfront Park
Smith And Bybee Wetlands Natural Area
South Waterfront Park
Willamette Cove Park

Previous COA Associations

Previously Associated with (2006 COA IDs)
- CR-09 (Portland’s Forest Park)
- WV-01 (Columbia River Bottomlands)
- WV-03 (Willamette River Floodplain)
Size Change from 2016 boundaries: No change

Specialized Local Habitats

Basalt cliffs
Bottomland hardwood forest
Off-channel habitat
Shoreline and sandy beaches

Ecoregions

Coast Range

Oregon's Coast Range, known for its dramatic scenery, is extremely diverse, with habitats ranging from open sandy dunes to lush forests and from tidepools to headwater streams. It follows the coastline and extends east through coastal forest to the border of the Willamette Valley and Klamath Mountains ecoregions

Willamette Valley

The Willamette Valley ecoregion is bounded on the west by the Coast Range and on the east by the Cascade Range. This long mostly level alluvial plain has some scattered areas of low basalt, and contrasts with productive farmland and large urban areas. It has the fastest-growing human population in the state resulting in challenges due to land-use changes.

Key Habitats

Grasslands

Grasslands include a variety of upland grass-dominated habitats, such as upland prairies, coastal bluffs, and montane grasslands.

Late Successional Mixed Conifer Forests

Late successional mixed conifer forests provide a multi-layered tree canopy, including large-diameter trees, shade-tolerant tree species in the understory, and a high volume of dead wood, such as snags and logs.

Natural Lakes

Natural lakes are relatively large bodies of freshwater surrounded by land that were formed through geological processes, such as glacial scouring, tectonic movements, volcanic activity and river meander cutoffs. In Oregon, natural lakes are defined as standing water bodies larger than 20 acres, including some seasonal lakes. Depth is not a reference for characterization of …

Example of Oak Woodlands, which is a Strategy Habitat within the State Wildlife Action Plan

Oak Habitats

There are several oak habitat types in Oregon, where oaks comprise most of the canopy. These can include oak woodlands, oak forest, oak chaparral, and riparian oak. Oak savanna is covered in the Grasslands Key Habitat. Oaks may also co-dominate a canopy in oak/fir, oak pine, and oak hardwood habitats.

Flowing Water and Riparian Habitats

Flowing Water and Riparian Habitats include all naturally occurring flowing freshwater streams and rivers throughout Oregon as well as the adjacent riparian habitat.