Restoration of South Scappoose Creek in the works
Can Scappoose transform a flood-prone stream, parts of which resemble a glorified ditch, into a picturesque amenity with walking trails and prime habitat for salmon and steelhead?
Scappoose residents will begin to find out this summer as an ambitious restoration project unfolds to transform South Scappoose Creek.
"This restoration is going to make a big difference in reducing flooding and helping fish," said Scappoose City Manager Mike Sykes.
The Scappoose Bay Watershed Council is leading the $400,000 project, which includes a $265,865 grant from the Bonneville Power Administration and $75,000 from the city of Scappoose. The BPA is also contributing a $93,813 grant to restore lower North Scappoose Creek that merges with its south fork counterpart, just north of Scappoose.
The headwaters of South Scappoose Creek begin in the high Coast Range in west Columbia County, near Vernonia. The creek briskly flows through leafy forestlands and then slows in the lowlands near the Columbia River. It originally had strong salmon and steelhead runs and a thriving cutthroat trout population, but nearly a century of human encroachment and invasive species have greatly degraded the fish habitat.
"The issue has been 150 years in the making," explained Pat Welle, SWBC director.
The major problem is a disconnection of the main creek channel to the floodplain, throughout much of the lower South Scappoose, she said. That means the higher winter water flows have no land to spread out, causing the force of the steam to increase and create deeper incision — cutting down into the stream bed — that increases the disconnection from off-channel areas.
"There's also a lack of wood in the system due to logging and past practices of removing large wood from the stream channel," Welle explained. Large wood creates healthy habitat complexity and pools, helping salmonids and other species, she said.
All of this has been occurring for a very long time — with timber harvest, farming and residential development activities, Welle concluded.
The elimination of tree cover and invasive species also raised water temperatures and made banks less stable and accessible to the public.
South Scappoose and North Scappoose creeks merge to form Scappoose Creek. The creek then flows into Scappoose Bay, which has large and small mouth bass, blue gill and other pan fish.
The creek's north fork has been historically stocked with rainbow trout, and a successful water quality restoration might draw some rainbows upstream into the south fork.
Two previous studies of South Scappoose Creek, done in 2009 with 2013, developed restoration designs.
"But the project really kicked into gear came after winter storms two years ago that flooded property and eroded so much soil, it exposed sewer pipe lines," Sykes said. "While the Federal Emergency Management Agency helped with repairs, the flood was a wake-up call."
Proposed actions include bank laybacks to minimize active bank erosion and increase capacity during high flows, and side channel reconnections to access historic off-channel areas.
The restoration will cover three-fourths of a mile of the creek that meanders through a portion of the city encompassing Highway 30. The project spans two parcels — the creek through Veterans Park as well as the parcel immediately upstream of the park, south of Southwest JP West Road, Sykes said.
All work is being done on the west side of the creek.
"We're now in the final engineering phase and will soon be requesting bids from contractors and hope to begin construction by late June or July," Welle said.
Initial construction will see the placement of wood embankment planks on the west side of the creek to duplicate the natural effect fallen logs have in helping stream quality. The project will also create more slope banks to allow rising water to spread out and reduce velocity, rather than dig deeper into the stream bed.
"Sometime in late fall or next winter — during the rainy season — we'll begin native vegetation planting" including a host of native alders, maples, ashes and willow trees, Welles added. More than 9,000 plants and trees are scheduled for planting. The SWBC will provide opportunities for volunteer organizations to help.
The city is also separately scheduling research this summer to plan for a pedestrian trail. Sykes explained that a University of Oregon graduate student will study potential trail sites and designs, Sykes said.
Other project partners include the Columbia Soil and Water Conservation District, Oregon Department of Fish and Wildlife, and the Oregon Watershed Enhancement Board.
For more information, visit www.scappoosebay-wc.org.