The Third Street underpass in Bend will close from 7 p.m. today through 7 a.m. Monday while a subcontractor fixes a problem in the city project. The city also plans to close the underpass one more time this week to lay striping and adjust manholes.

The primary contractor, Jack Robinson and Sons Inc., is not charging the city for the pavement repairs, said Project Manager Eric Forster, who works for the city. The paving subcontractor is 7 Peaks Paving, of Bend.

Contractors began work on the Third Street underpass project in early July and wrapped up most work, so the road has generally been open in recent weeks.

“There were some issues with the flatness of the cross slope of the road, and it wasn’t providing the positive drainage that we need, particularly for our stormwater job,” Forster said.

To correct the problem, 7 Peaks Paving will apply another layer of asphalt this weekend.

In preparation for the work, the contractor ground up edges of the road, near the curbs. This was necessary to ensure the proper angle for drainage and adequate depth along the curbs, Forster said.

It’s important for the underpass to have effective drainage, because the project centerpiece is a stormwater well and pump, which will send the water to a drainage pond near U.S. Highway 97.

In the past, stormwater often flooded the underpass; the water could also carry hazardous materials from spills in the area directly into the ground without filtration, through an old stormwater well. The paving contractor was going to apply the additional layer of asphalt on Sept. 30, but had to reschedule due to a recent cold snap.

“While we don’t like to have things redone, the contractor understands they didn’t meet the specification and they’re going to do it,” Forster said.

The improvement project cost an estimated $3.4 million, City Manager Eric King said in April. It’s paid for from stormwater utility fees of $4 per single family home or per 3,800 square feet of impervious surface. The city started charging the fee in 2007.

About 16,000 vehicles pass through the stretch of Third Street encompassing the underpass, and 10 trains per day pass over the street.