Pierce County bridge blocked critical salmon routes for nearly 80 years. The fix is $53M
The Chambers Creek Bridge has served as an essential roadway connecting Steilacoom and University Place for 78 years. But its deterioration and blocking of a critical fish passage means it will have to be replaced in the next decade or so.
A plan to remove and replace the bridge is expected to cost around $53 million, according to the Pierce County Planning and Public Works Department. To restore the natural tidal systems and salmon habitat of the area, Pierce County plans to remove the 100-year-old Chambers Creek Dam downstream as well.
“This is a larger effort for [the] Chambers Bay [Estuary] restoration. However this part, the bridge replacement, is the first domino that needs to fall,” Sean Goldsmith, county salmon recovery senior planner, said in a presentation to the Pierce County Council on Thursday night. “It’s a three-part restoration: a bridge replacement, a dam removal and shore restoration.”
Funding for preliminary designs and related project studies have come from Pierce County Surface Water Management funds and other grants, according to the county’s informational website on the project. Overall project restoration costs are expected to be between $40 million to $60 million over the life of the project, and Pierce County is reviewing state and federal infrastructure grants as long-term funding sources. Dam removal is expected to cost between $3 million and $4 million, Goldsmith said.
The project is happening in partnership with the Puyallup Tribe of Indians, Squaxin Indian Tribe, Nisqually Indian Tribe, Forterra, Pierce County, Steilacoom and University Place, with input from a number of other stakeholders.
Project planning is expected to take another two to three years, followed by several years of design and permitting finalization, then several years of construction to remove the bridge and dam and construct a new bridge, according to a Planning and Public Works presentation to the council last week.
What would the new bridge look like?
The existing bridge was built in 1946 and is 65 feet long and built from three-span timber pile-supported concrete slabs, according to a final type, size and location study of the replacement bridge. The Chambers Creek Bridge has been deemed “structurally deficient” and would be unable to withstand the hydraulic conditions once the Chambers Creek Dam is removed, the report said.
“If the dam were simply removed, we would be undermining the road that’s there and potentially have the road collapse. It could be a catastrophic failure,” watershed services supervisor Tom Kantz said Thursday in response to a question from Council member Jani Hitchen. “We don’t want that. And so we think it’s better to take a really close look at the entire site, including the bridge, the dam and all the restoration … and come up with a master strategic implementation plan.”
The existing Chambers Creek Bridge has minimal shoulder width and no pedestrian crossing despite a trail head on either side of the bridge, Goldsmith said Thursday.
The new recommended bridge design would expand the road to include shoulders wide enough to accommodate a bike lane on either side, as well as a 12-foot wide shared use path on the west side of the road that would connect to the East Slope Trail and the Chambers Creek Canyon Trail, Goldsmith said.
The design also includes a trail head parking lot, so hikers don’t have to park on the side of the road, as well as a pedestrian crosswalk, he said.
A new three-span precast girder bridge was the leading recommended design, with a 240-foot span over the channel for fish habitat, Goldsmith said in the presentation. This design was chosen compared to others for its lower construction cost, reduced wall and fill quantities and minimal long-term operation and maintenance costs, according to the study.
The $52.6 million price tag for a new bridge includes about $26 million in construction costs, $10.3 million in contingency costs, $7.2 million for engineering design, $9.1 million for construction management and administration and $46,500 for right of way costs, according to Goldsmith’s presentation. Comparatively, other bridge types considered would cost $61.2 million and $63.2 million to build.
