An Oak Harbor resident’s observation at Deception Pass Bridge led to a $750,000 project that will affect nighttime traffic over the bridge this fall.

Work on the waterlines running under Deception Pass Bridge will mean a lane closure Monday night followed by a month of nightly lane closures beginning in October, the Washington State Department of Transportation reported.

Two years ago, a resident noticed some of the bridge hangers holding the water mains on the bridge were rusting through and sent photos to the city. In response, the city contracted with Gray & Osborne to inspect the water mains attached to the bridge. The consultant recommended replacing many of them, but the city decided to replace them all.

In August, the council approved a $686,000 bid from Bridge Masters, Inc. to do the construction work.

Oak Harbor gets most its water from the Anacortes treatment plant on the Skagit River in Mount Vernon, which travels across the bridge via the pipeline.

The contractor crews will do some pre-construction work from 8 to 11:59 p.m. on Sept. 12. They will close a lane nightly, and flag traffic through the open lane, when work resumes Tuesday, Oct. 11 until approximately Wednesday, Nov. 9. The overnight weekday work will start at 8 p.m. and finish by 5 a.m. each day, the state reports.

Travelers in the area can get real-time traffic information on their phone with the WSDOT traffic app, by tracking the WSDOT traffic Twitter feed, and get advanced information from the Mount Baker area construction page.