Keeping the river environment healthy

From ODOT-

When the original Willamette River Bridge was constructed between 1959 and 1961, workers built diversion dams and filled portions of the river to provide access to the work-site and to capture debris from the construction. Today, with much more knowledge, we understand the environmental impacts on the river from construction and have plans in place to limit them.



Traveling on Franklin Boulevard or on nearby pedestrian paths, you will see the machinery tearing down the temporary detour bridge. However, you may not notice what our contractor built to protect the river and use as a work platform, just as they did for the southbound bridge work in 2009.



Directly under the detour bridge, 10 feet above the river’s ordinary high-water level and covering almost 120,000 square feet, is the work bridge. To build the work bridge we first drove steel piles into the river, connected them with large steel beams and then added a work surface of large timbers and plywood. The surface is sealed with an impermeable plastic layer, capturing any runoff and carrying it through pipes to an offsite treatment system before the water is released.



Workers will place sand on the work bridge to cushion large pieces that fall during demolition, but will remove it afterward to keep it from clogging the drainage system.



The work bridge is strong enough to support heavy equipment used in demolition and construction, large enough to capture falling debris from demolition of the temporary bridge and secure enough to build the wooden forms, or falsework, needed to create the new bridge arches.



We are pleased our efforts to protect the river are successful, while at the same time allowing for efficient construction of the new bridge.