N.A. Degerstrom Inc., of Spokane Valley, has begun work on a bridge replacement project in the Chattaroy area under a $1.2 million contract awarded by Spokane County.

The project, which will replace a bridge that carries Chattaroy Road across Dragoon Creek just east of Perry Road and between U.S. 395 and U.S. 2, began June 14. The new bridge is expected to open in November, although some follow-up work will be done on the project until next spring, says Spokane County bridge engineer Neil Carroll.

During construction, Chattaroy Road will be closed in the vicinity of the bridge, and traffic will be diverted to Denison-Chattaroy Road, which is located to the north.

The project includes constructing an 85-foot-long, two-lane bridge that will replace a 30-foot long bridge there now, along with work on Chattaroy Road on both of the bridge's approaches, says Degerstrom project manager Keith Peterson. The new precast girder bridge will be five feet wider than the old bridge, and the county says the roadway near the bridge also will be five feet wider.

Carroll says the bridge replacement was necessary because Dragoon Creek's channel shifted to one side, and the stream caused erosion around a bridge abutment, which cracked and became unstable.

Carroll says the abutment was temporarily repaired three years ago, and traffic across the bridge was reduced to one lane while county engineers designed a new bridge and sought funding for the replacement span. The new bridge will use a combination of deep foundations and footings bearing on bedrock to ensure that it won't be damaged by scouring of the creek bed.

About 80 percent of the project cost will be paid for with federal funds, and 20 percent will come from county road funds, Carroll says.