Text Size:   A+ A- A   •   Text Only
Find     
Site Image

New life for the I-5 Willamette River Bridge
Bringing new life to the I-5 Willamette River Bridge
 A blue heron rests on a log near the I-5 Willamette River Bridge.
A blue heron rests near the I-5 Willamette River Bridge.
If you were a great horned owl soaring overhead, the Willamette River would appear as a deep blue snake of water winding its way up from the valley just south of Eugene to the Columbia River in Portland. Homing in on the spot just between Eugene and Springfield, where bustling streets, lush prairies and giant Douglas fir and oak trees surround either side of the river, you'd be able to pick out more than cars moving up and down Interstate 5 and people strolling through Alton Baker Park.
 
Western pond turtles and North American beavers call the riverbanks home. Oregon chub, Chinook salmon and steelhead, bull and rainbow trout are all travelers through the area, stopping to spawn and feed. Myotis bats, herons, osprey, hummingbirds and butterflies find shelter in local trees and plant life. And for most of these animals, the Willamette River Bridge has long been a fixture in their habitat.
 
That's why the project team replacing the bridge is taking such care to ensure that the area below, around and above the structure is enriched and protected by the bridge's construction.
 
"Our team does everything we can to ensure that the bridge's footprint is as small as possible," said Geoff Crook, ODOT environmental program manager. "We’re working with land and waterways that will continue to flourish and evolve for decades to come, so we don’t want to get in the way of that."
 
By discussing options with local park departments, stakeholders and residents, the team was able to fully understand not only the needs of the people who would eventually drive over the bridge, use the surrounding park lands and float in the river below, but also the requirements of wildlife in the area.
 
"If you’re speeding down I-5 over the river, you might not notice much of a change," Crook said. "But if you look a little closer, you’ll see a lot of positive changes the bridge will have on its environment."
 
These types of benefits are not unusual: All OTIA III bridge projects aim to avoid, minimize or mitigate environmental impacts. But the rebuilding of the I-5 Willamette River Bridge, one of the bridge program’s largest undertakings, has taken being green to a new level.
 
Lightening the footprint
Although the original Willamette River Bridge was a strong, well-planned structure when it was built, the agency's attention to environmental protection and sustainability has come a long way since 1962.
 
In preparation for the bridge demolition process, crews built a work bridge to support the construction crew and the machines used for deconstruction. This structure also helped protect the river's fish and other wildlife from debris that could otherwise fall into the water when they dismantled the bridge. The platform stretches across the width of the Willamette River and stands approximately 10 feet above the high-water mark. This containment structure will eventually be taken apart and reused on the other side of the bridge for additional demolition, cutting down on both the cost and waste of a new structure.


During bridge construction, the team also uses "bubbleators," devices made from foam, sheet metal and aluminum pipes that generate a strong froth of bubbles to mute the noise from pile driving underwater. The primary purpose of a bubbleator is to help protect fish from in-water sound pollution, which can negatively affect their communication and migratory patterns.

The bridge crew uses a bubbleator to reduce effects of sound pollution. 
The design of the bridge is pleasing both visually and ecologically. The original Willamette River Bridge had five piers in the river, and the temporary bridge had eight. Once the final bridge is complete in 2013, the new deck-arch columns will take up significantly less space and provide less of an obstruction for animals in the river, touching the water only once in the middle on a natural island.
 
"This bridge is a marked improvement from what was there previously, and not just from a visual perspective," Crook said. "The open arches of the new design will complement the flow of the Willamette River rather than serve as a barrier for fish and people to navigate around."
 
Surrounding improvements
In addition to the bridge itself, the bridge design includes a number of notable improvements to the land near the structure.
 
Once construction is done, the park land around the bridge will be restored to equal or better condition than before. The agency will repave walking and biking paths for safer use and restore twice the number of native trees and plants to the area.
 
Another improvement will be the restoration of a fish tributary connected to Augusta Creek and Glenwood Slough. Over the years, upper habitats have been cut off by road use, and fish populations have dropped. Now, the project crew is reshaping the area to its natural state by widening the channel and removing barriers for easier fish access to “"et the stream be a stream," Crook said.
 
"Overall, the Willamette River Bridge replacement enhances more than the quality of life in the Eugene-Springfield area," Crook said. "The new bridge will strengthen the entire I-5 corridor and improve the health of the surrounding tributary system."