Motorists traveling Interstate 25 near the site of last week’s massive sinkhole will be using three temporary northbound lanes for the next week and a half.
The Colorado Department of Transportation announced Sunday that it will launch permanent repairs of the site on Tuesday, reversing an earlier decision to wait until spring.
CDOT spokeswoman Stacey Stegman said the change is expected to save $700,000 in repair work and take far less than the estimated month of work if it had been done later.
Permanent concrete repairs on the highway where the ground collapsed at 56th Avenue will take about 10 days, Stegman said.
The 58th Avenue exit is expected to reopen tonight.
“We are already here, we are going to just finish what we started now,” Stegman said Sunday.
Concrete paving can occur while traffic runs on the other side of a barrier on the temporary lanes. Then, traffic can be switched onto the new lanes while the asphalt detour is replaced with concrete.
CDOT estimates the cost of repairing the roadway at between $1 million and $1.5 million, Stegman said.
Denver Water Department crews have been repairing the conduit and were laying a quick-setting FlashFill around the pipe on Sunday afternoon.
Denver Water hasn’t yet determined the cost of repairing the main, said water department spokeswoman Stacy Chesney. “The plan is for CDOT and us to sit down and discuss how we will handle the cost of the project,” Chesney said.
Water swallowed some northbound lanes near the 58th Avenue exit on Thursday when the concrete conduit more than 5 feet wide gave way, spilling more than 2 million gallons and opening a 40-by-40-foot sinkhole 16 feet deep.
Crews have been working round-the-clock on the 66-inch conduit since it broke. Water department crews installed approximately 34 feet of steel pipe before finishing.
The original steel conduit was installed in 1978. An electrical malfunction in a pump’s controls caused a surge in pressure that ruptured the pipe.
Besides the three temporary lanes, commuters can use I-25 high-occupancy-vehicle lanes. Solo drivers will be required to pay the toll.
Delays are possible, and CDOT recommends using an alternate route, taking public transit or carpooling.
Tom McGhee: 303-954-1671 or tmcghee@denverpost.com
