The MBTA says it is reopening the Green Line between the Reservoir and Newton Highlands stations, four days after part of the trackbed was undermined by rushing water from the recent downpours.
The line is expected to reopen at about 2:30 p.m., in time for commuters heading home for the weekend.
The MBTA had previously said the line would be closed at least until Monday.
The work was completed early, thanks to the "remarkable efforts of crews working around the clock," T spokesman Joe Pesaturo said in an e-mail.
Surging water from this week’s storm created a 12-foot-deep hole under the tracks on the Green Line’s D branch, east of the Newton Centre stop.
Passengers who use the branch have been shuttled on buses between the Newton Highlands and Reservoir stations, adding at least 20 to 30 minutes to most commutes.
At a press conference earlier this week, state Transportation Secretary Jeffrey Mullan gave assurances that the repair would last.
“This will be a permanent fix,’’ he said. “We’re not putting the line back in service unless we’re 100 percent sure it’s safe, and that means a permanent fix.’’
The sheer size and depth of the hole suggested there had been a powerful surge of water downhill, most likely coming from the nearby Webster Conservation Area.
Mullan said the problems that arose from the storm were unique.
“We are constantly walking tracks looking for issues that need remediation,’’ he said, “but I don’t know if any special steps need to be taken, other than what the MBTA safety engineers do on a daily basis.’’