S. John Collins / Baker City HeraldBaker City Department of Public Works crews continue a curb and street project Tuesday on Auburn Avenue between Second and Fourth streets. Workers are, left to right, Brian Johnson, Scott Foss and mini excavator operator, Blain Leamaster. Foss said the 2-foot-deep trench will contain recycled concrete as base material for new curbs.

The four-block section of Auburn Avenue from Main Street west to Fourth Street is an area drivers might want to avoid for much of the rest of the summer.

“Basically from now through the end of September people can expect on-and-off street closures and quite a bit of work going on,” City Engineer Doug Schwin said.

City crews and contractors will be rebuilding the sidewalks and curbs and repaving the street as part of a $681,000, project that started this spring.

Utility work, including moving water lines and upgrading stormwater and sewer systems, has mainly been finished.

This week and into early next week, city crews are working on the section between Second and Fourth streets.

“This month the city is doing the prep work,” Schwin said. “We’re kind of doing that in stages.”

Several sections of the street will be closed at times in July as city crews prepare the street for the contractor, who will build new sidewalks and curbs, Schwin said.

The prep work between Second and Fourth streets should be done by Tuesday, July 18.

Then Auburn will be closed between First and Second streets for the rest of next week. The block between Main and First streets is slated to be closed for the following week (July 24-28) to finish the curb and sidewalk removal. Schwin said work on that block might extend a day or two into the following week.

“We’re getting all the base prepped for the curbs and the sidewalks,” Schwin said.

Auburn Avenue will be reopened on the weekends throughout the construction period.

A contractor will begin pouring concrete for the sidewalks and curbs in early August. That work is estimated to be complete by Aug. 25, Schwin said. He doesn’t anticipate any full closures of the street during that time, but there will be lane closures to accommodate concrete trucks.

Another contractor will do the repaving, using a process called full-depth reclamation. It’s a type of paving that does not involve total street reconstruction, such as the rebuilding of Resort Street in 2013.

The contractor will begin that phase of the project Sept. 6 and should finish by Sept. 15.

The first step is grinding away the top 3 inches of asphalt. Schwin said there will be no full closures of Auburn for that step — just the lane that is being worked on.

The next step involves pulverizing the remaining asphalt, then mixing it with the underlying roadbed material and concrete to create a new street surface.

Schwin said a machine pulverizes the remaining layer of asphalt and mixes it with the 8 or 9 inches of material under the street.

“It just blends it all up and basically rototills it,” he said. “It completely destroys the asphalt layer that’s there.”

See more in the July 12, 2017, issue of the Baker City Herald.