View entire map This TPA project will replace the old, narrow bridge over Chiwaukum Creek, just above Tumwater Canyon (MP 89.88-89.91), ten miles west of Leavenworth in Chelan County.
View entire photo The new bridge will carry more weight and be much wider.
View entire photo A closer view, looking north at the south side of the bridge.
Fall 2009
During the week of April 6th, 2009, a Value Engineering study was done for this project. That brought together design, engineering and construction experts inside and outside the agency to analyze the data and options to finalize a design and construction plan. Survey data, geotechnical information, and environmental resource data were gathered to design the different alternatives to minimize environmental impacts and maximize cost efficiencies. Depending on the final design option chosen when the results of the VE Study are compiled, this project may take two seasons to complete.
Construction is scheduled for 2011.
This Catastrophic Reduction Structure Preservation project replaces an old bridge on US 2 just above Tumwater Canyon, ten miles west of Leavenworth in Chelan County.
Why is WSDOT
replacing the Chiwaukum Creek Bridge?
The current steel girder structure is functionally and structurally obsolete, which means it doesn't meet today's design standards for traffic loads (weight) and roadway width. Originally built in 1936, the bridge has undergone various retrofits to improve the deteriorated concrete bridge rails and also to try to reduce undermining of the footings from Chiwaukum Creek due to scour. (Washing out the soil under the footings). The age and design of the bridge requires regular maintenance and doesn't allow for widening so replacement is the only option.
The End Result
The current proposal for a new structure includes two 12-foot lanes with 8-foot shoulders. A great improvement over the current bridge which has two 12-foot lanes and no shoulders. The new structure will also be reconfigured to span Chiwaukum Creek with less impacts to the stream, reducing the need to clear debris (logs jams, etc.) from the bridge footings after high flow events and eliminating the undermining of the foundations due to creek scour.
Project Benefits
Traffic Safety - Provides a wider bridge with shoulders to pull onto.
Truck Safety - Oversize loads will also be better accommodated with a wider bridge deck.
Pedestrian and Bike Safety - Two 8-foot shoulders provide bicycles and pedestrians a much safer crossing.
Environmental - Reconfiguring the creek crossing and the new bridge's design will reduce backwatering and debris accumulation. Replacing the old steel girder bridge with a concrete girder structure, eliminates the need to paint it on a regular basis. Fish enhancements to the creek bed are also included in the design.
What is the project timeline?
The project is currently in the initial design phase, with a scheduled construction start in late Spring 2011. Depending on the final design option chose, this project may take two seasons to complete.
This project is planned to be constructed in conjunction with the US 2 - Wenatchee River Bridge Replacement, which is located 3/4 of a mile to the east at the head of Tumwater Canyon.
Financial Information
This project is funded through the following source:
How can I get more information?
Contact:
Bob Romine, Project Engineer
WSDOT North Central Region
P.O. Box 98
Wenatchee, WA 98807
Phone: (509) 667-2880 or toll free (888) 461-8816
Email: rominer@wsdot.wa.gov
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