Tree Removal and Revegetation Plans
Trees will be removed and replanted for new bridge and interchange
Construction activity is gearing up to replace the Sellwood Bridge and its interchange with Highway 43 (SW Macadam Avenue). To accommodate construction of the new bridge and interchange that will be built, a large number of trees (approximately 813) will need to be removed. The majority of these trees will be removed in April 2012.
The tree removal plan has been carefully developed to preserve as many healthy, mature trees as possible. The Project’s landscape design for the natural areas along the Willamette River and Highway 43 call for more trees to be planted than will be removed. While the tree removal will change the appearance of vegetation in the short-term, the newly planted trees will provide a healthy canopy in the long run. Native trees and shrubs will be planted that will be cared for by Multnomah County through the five-year establishment period.
Highway 43 view north - 10 years after project completion
Here are some frequently asked questions about the tree removal and revegetation plans:
Why do trees need to be removed?
The trees need to be removed because they are unavoidably within the construction zone for approved project improvements. These include improvements to a half-mile long section of Highway 43 north and south of the bridge, landslide stabilization near the west end of the bridge, retaining walls and bridge piers. Some trees interfere with extension of the Regional Trail from S.W. Miles Street to the bridge, and removal of the fish passage obstructions at Stephens Creek. The new bridge and interchange will be built to modern standards and will take up more land than the existing bridge and interchange, which are very narrow by comparison.
Where are the areas where trees will be removed?
About half the trees to be removed are on City property (Butterfly Park, Powers Marine Park, River View Natural Area, and Willamette Moorage Park) and Hwy 43 right-of-way. Other trees are on property owned by Riverview Cemetery and the Willamette Shore Trolley right-of-way. A few trees are on the east side of the river, either on private residential property or on the east river bank.
What types of trees will be removed and what condition are they in?
An arborist hired by Multnomah County surveyed the condition of the trees in the fall of 2011. The survey documented the general health and condition of trees greater than 6” in diameter that were identified for removal. Many trees are in poor or fair condition. Most of the trees are along the river and on the west side of Highway 43. Native species to be removed include Douglas Fir, grand fir, red alder, vine maple, Western hemlock, and yew. Non-natives and invasive species to be removed include English ivy, clematis, elm, English laurel, European white birch, holly, and Norway maple.
How many trees will be removed?
An estimated 813 trees will be removed. The vast majority are on the west side of the river. A few are on the east side, either on the river bank or on residential property near the bridge.
How many and what types of trees will be replanted at the end of construction?
The City of Portland land use decision requires planting 1,516 trees and 1,773 shrubs within the project area. The plant materials are all native species selected from the Portland Plant List. Also, riparian tree planting will occur at Willamette Moorage and Powers Marine parks in association with stream restoration and historical fill removals.
The tree removal plan was addressed as part of the City of Portland’s land use review (a Type 3 Environmental/Greenway review), and as part of the "Non-Park Use Permit" for tree removals on city-owned land, including parks and city right-of-way.
The land use decision by the Hearings Officer approved the tree removal. The decision was not appealed. It has been recorded and finalized.
The land use decision set the requirements for tree replacement and mitigation. The decision noted the size and quality of trees to be replanted.
What measures are taken to protect wildlife such as birds during tree removal?
The project schedule is timed to avoid injury to migratory birds. Project team members make regular visits to the tree removal area to confirm that resident and migratory birds are not building nests. The project’s goal is to remove trees this year before bird nesting begins. Other wildlife is expected to disperse once felling begins.
How will trees that remain be protected during construction?
Tree protection measures include fencing and other demarcation depending on the location. A certified arborist will inspect the trees each month to monitor their health and recommend additional protection measures if needed. A pre-construction meeting including the arborist and staff from City agencies will be held before each major work phase to confirm the boundaries for fencing and other tree protection measures, and that erosion, sediment and pollution controls are adequate and comply with approved plans.
English ivy covering trees along Hwy 43
Do the landscape plans offer any environmental benefits?
English ivy and other non-native, invasive species will be removed. Trees in poor condition will be removed. All replacement trees and shrubs will be native species. The replacement trees and shrubs will be cared for at least 5 years until they are established. Densities of the plantings are designed for full stocking and invasive species control, without crowding. Numerous shoreline areas presently without important native woody riparian cover (including existing buildings and pavement) will be restored to continuous vegetative canopy, which will improve streamside and habitat support functions.
What happens to trees that are removed?
Smaller trees will be chipped and the mulch will be used onsite or in other landscaping locations. Some trees near the river will be removed with their roots intact and placed in Powers Marine Park to enhance riparian habitat. A few cedar and yew trees will be made available to the Grand Ronde tribe to use in making traditional items such as bows, arrows, medicines, or baskets.
Is any of the downed wood available to citizens?
No. Most of the downed trees are small and are chipped for use onsite as mulch. Other trees with roots intact are reused as riverbank habitat. The Grand Ronde tribe will receive several cedar and yew trees to make traditional tribal items. A few large trees could be sold to a lumber mill by the contractor.
When will new trees be planted?
Permanent landscaping will be installed as final grading is completed, which will vary within the construction zone. Advance planting, up to three years prior to project completion, will accelerate growth and development, and assurance of success.
For more information or if you have questions, contact:
Multnomah County Communications Office