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.
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.
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.