D2’s Spalding Bridge project wins award for environmental considerations

The Spalding Bridge repair project in Lewiston, completed in early fall 2014, has again been recognized by a national transportation organization. The first recognition, several months ago, was for innovation. This time, the project was honored with an American Association of State and Highway Transportation Officials (AASHTO) President'sTransportation Award for Environment.

The award will be presented at AASHTO’s annual meeting in Chicago Sept. 27.
 
ITD’s Spalding Bridge Project saved a critical 1,200-foot bridge (pictured top) over the pristine Clearwater River, while also enhancing habitat for threatened fish species such as bull trout, Snake River Basin steelhead, and Snake River fall Chinook salmon, in addition to other rare species such as Westslope Cutthroat trout.

The Clearwater River is one of the most scenic rivers in the United States. It has robust populations of fish and wildlife, and is rich in history. The Middle Fork of the Clearwater River was one of the first rivers designated under the U.S. Wild and Scenic Rivers Act. Anglers and paddlers from all over the world travel to experience the Clearwater’s thriving fisheries, thrilling whitewater, and spectacular scenery.

The project involved a fast-moving body of deep water that runs at an average 15,300 CFS, requiring ITD to develop innovative mat-placement techniques. The water moves too fast for divers to be deployed, so ITD developed unique solutions involving GoPro cameras, time-lapse photos, and aerial monitoring from a drone to ensure proper placement of A-JACKS mats. A-JACKS is an articulated riprap technology that provides armoring protection for bridge foundations and piers.

Crews placed nearly 400 concrete A-Jacks mats, weighing 2,700 pounds each, on the riverbed to provide armor against erosion. The voids in the mats provided a support system for the river gravel and improved fish habitat. A segment of underwater A-JACKS mats is pictured to right. Pictured above are crews working at a bridge pier during the project.

This project was time-critical because the bridge, built in 1962, was rated among the top 10 most scour-critical bridges in the state. The A-JACKS technology helped ITD complete the project ahead of schedule and under budget. Because of heavy river flows, had this project not been done, the bridge could have failed, resulting in injury, loss of life, and destruction of critical habitat for bull trout, Chinook salmon, and steelhead—all threatened species. This technology provided substantial environmental benefits to the marine life and to the Nez Perce Tribe, who rely on the fish for sustenance. 

ITD coordinated with the Nez Perce Tribe’s employment rights office and the Idaho Department of Fish and Game, and obtained permits from the Environmental Protection Agency (particularly the 401 permit). Half of the crew working on the project were Nez Perce Tribal members.

This marked the fifth AASHTO President’s Award ITD has won in the past six years.


Published 07-31-15