LAMORINDA WEEKLY | Major repairs on the Miner Road sinkhole are zooming ahead


Repair work on the Miner Road sinkhole is progressing nicely. Photo Sora O'Doherty

Orinda is speeding through the repair of the Miner Road sinkhole and is on course for the road reopening in early July. Carpenter foreman Jerry Say explained that the rectangular culvert is now complete, and the work has moved on to the walls.

According to Orinda Interim City Manager Steve Salomon, the rebar for the parapet and retaining walls on each end of the box culvert has now been installed and the wood forms for the parapet wall set on top of the end of box culvert were set up for a concrete pour on May 26. The retaining walls are designed to stair-step down into the creek channel. They vary in height between five-feet and 22-feet tall.

The wood forms are set on each side of the rebar. The concrete for the retaining walls will be poured June 2, and that will be the last major concrete pour for the project. Salomon also noted that the contractor will likely begin backfilling over the box culvert and behind the retaining walls the weekend of June 3. The contractor will be importing structural backfill and delivering it to Miner Road off Camino Pablo.

Public Works Director Larry Theis explained that among the work still to be done are the reinstallation of utilities and sewer lines and placement of high flow storm drain pipes; the city is working with EBMUD to replace the water line.

Theis was delighted that it was not necessary to remove additional trees from the site. He addressed the use of the Orinda sports field for stockpiles of dirt, acknowledging some complaints regarding noise and dust. He said that it will probably be a month before the material can be off-hauled, and it will be taken out at night to another job site in east Contra Costa County. The city will work with neighbors to mitigate noise and other concerns. Theis believes that it will be better to do the hauling at night, because it will take only three to five nights to remove the dirt, whereas if the work were done during daylight hours it would take eight to 10 days owing to traffic. Noise will be an issue from 8 p.m. to 4 a.m. Notification to neighbors will be provided as to exact time frame and the city will try to look at other mitigations.

Theis also reported on the status of services through the area. The PG&E gas pipeline is being suspended and will be buried back in place, no reconnection will be required. The Central Contra Costa Sanitary District is negotiating with the city's contractor for a price to reinstall the two sewer lines.

EBMUD also recently tested the pipe, which is still in good condition, but it will remove and replace a 40-foot section. The pipe replacement will take two days.

Theis also said that the city will address larger potholes towards the end of the project, and that they are still working with Caltrans and Federal Emergency Management Agency concerning reimbursement.