Project Overview
The Smith River Estuary has been modified over the years by a
number of projects that have diked and drained wetland areas in the
estuary so they could be used for livestock grazing. Levees, tide
gates, and dredging were all common practices from the 1900s to the
1960s.
The Dawson property near the mouth of the Smith River has been
diked and used for agricultural purposes since the early 20th
century. Since the floods of 1996-1997, however, the existing levee
has been breached in three places, resulting in daily tidal
inundation of the property.
Wetland restoration and enhancement as the
answer
The Umpqua Soil and Water Conservation District (SWCD) received
a 319 grant of $85,000 from the Oregon Department of Environmental
Quality in August 1999 to help with the Dawson Wetland Restoration
Project. The landowners originally contacted the Umpqua SWCD for
assistance in repairing the dike, hoping to halt the flooding of
their property. Eventually, the project evolved into one that would
protect part of the property and return 30 acres to estuarine
wetlands.
The landowners agreed to donate 30 acres of their 100-acre
parcel to be restored as wetlands, along with construction of a new
levee to protect the remaining acreage for their homestead and
agricultural purposes. The Umpqua SWCD participated in fundraising
for the project and directs the project inspection and planting of
vegetation on the new levee. Additional partners, such as Ducks
Unlimited, are providing project management and engineering
assistance.
In addition to restoring the 30 acres of estuarine wetland, the
project also involved enhancing the 50-acre Stowe Marsh, just
upstream from the Dawson property and managed by the Oregon
Department of Fish and Wildlife. The marsh contained a levee with a
break in it, and the project removed a large portion of the levee
so that natural floodplain function could be restored.
Project activities
The Dawson Wetland Restoration Project was divided into three
phases. Phase I of the project, completed in 1999, included
installation of a tide gate, as well as development of engineering
plans and specifications. Phase II, completed in 2000, included
removal of two sections of the Stowe Marsh levee to enhance 50
acres of estuarine wetlands, construction of the new Dawson levee,
vegetation of the new levee and adjacent disturbed areas with
native plants, revegetation of borrow area, and improvements to
internal drainage on farmland inside the new levee.
During 2001 Phase III is removing the old failed levee on the
Dawson property, allowing the 30 acres outside the new levee to be
returned to estuarine wetland status. Title to the restored
wetlands on the Dawson property outside the new levee will be
transferred to the Oregon Department of Fish and Wildlife. Old
fencing in the donated wetlands will be removed. Plantings will be
fortified in the borrow area, and all interior drainage will be
routed to the new tide gate. Fencing will be installed around the
new levee to restore livestock grazing to the Dawson ranch.
Additional benefits
Erosion Protection. The existing levee will be left in place for
one winter to protect the new structure from erosion. Plantings
with native vegetation will be part of the bioengineered plan to
prevent erosion, making the use of riprap unnecessary. This
approach will also reduce future sedimentation into the river.
Fish and Wildlife Habitat Restoration. Various salmonid species
use estuaries as incubation areas for feeding, rearing, and staging
before they begin their ocean migration. The Smith River estuary is
already one of the most important areas in Oregon for threatened
coastal coho. The addition of 30 acres and the enhancement of 50
acres will provide 80 acres of the habitat needed for these species
and others. Waterfowl are also expected to use the restored
wetlands.
Restoration of Estuary Floodplain Function. One result of the
extensive diking of the Smith River system is that the river's
transport capacity has increased, resulting in higher river energy
against the city of Reedsport's levee. This project will result in
more water storage capacity in estuarine wetlands, moderating the
effects of flooding and reducing the river's erosive energy.
Public-Private Collaboration. This project represents a win-win
situation in which the landowners benefit by increased protection
of their homesteads and the public benefits from the enhanced
ecological functions provided by the restored wetlands. This
collaborative approach respects the existing land use that provides
the family's economic base while at the same time recognizing and
protecting the important public benefits from returning a portion
of the land to its former wetland status.