Mayor Martin J. Walsh sharply criticized Tuesday a decision by the city’s property management chief to hire a contractor to make emergency repairs on a weakened platform at City Hall Plaza, without alerting the mayor.
The property official, Michael Galvin, said in an interview that he needed to act quickly in anticipation of a crush of summer visitors. But he acknowledged that he did not solicit three written contract bids for the work as required under city rules, and he also failed to tell his boss, Walsh.
The mayor stressed in a phone interview that Galvin had been warned by city-hired engineers in 2012 that there was a problem with the structure, which covers a dormant water fountain, but instead waited two years before unilaterally rushing through repairs.
“In case of an emergency . . . I would say there’s an exception to the rule’’ on securing bids, Walsh said Tuesday. “But the problem was identified in 2012. There was really no exception to the rule in this case. I have spoken to Mike Galvin about this, and this is unacceptable.’’
Galvin acknowledged that while he was aware of the problem, he felt compelled to take action days before the massive Boston Calling festival, which drew some 60,000 fans to City Hall Plaza to dance, pump fists, and revel.
Engineers from Weidlinger Associates, hired by Galvin, had warned in 2012 about “structural vulnerabilities’’ and other failures.
The engineers returned in January when the Walsh administration took office. Galvin’s office erected a fence around the weakened site. The company filed a report in May and found that while the fountain cover was in acceptable condition, the fountain’s pool and sump area needed reinforcement.
“The area shall not be loaded with vehicles or pedestrians until the area can be shored,’’ the report said. “The allowable capacity is zero.”
Galvin said the engineers worried that with thousands of people converging on the plaza for concerts and festivals during the summer, crowds concentrated onto the weakened area could cause a collapse.
“I only had a short window of time before the summer is gone on me,’’ said Galvin, who had the job completed from May 16 to May 18. “I had three days to do it, and I stand behind the decision. That is what I get paid to do.”
The plaza issue, first reported Tuesday by the Boston Herald, is thorny for Walsh, who has been eager to put the sprawling brick and concrete concourse to better use and attract more people.
“There have been a lot of conversations about [how] we should try to use the plaza more, and now that we are trying to do that, we are finding out there is no structure for leasing the plaza and that we had a problem that has not been corrected,’’ Walsh said. “It’s upsetting.”
Galvin cited the recent stay of the Big Apple Circus on the plaza — featuring horses, llamas, and large trailers on or near the weakened patch — as evidence that no imminent danger existed.
“We had pretty large forklifts running back and forth, back and forth,’’ Galvin said. “I still don’t think there was a danger of collapsing. It never was.”
The platform in the middle of a concrete arc at a corner of the plaza covers what remains of the terraced water fountain, dedicated in fall 1969. The fountain was a problem from the day it opened, when it spewed polluted water that looked like green pea soup, according to Globe archives.
“It was the sort of pond, with brown and green foam, that no duck would wet its feathers in,’’ according to a 1972 Globe article. Its problems worsened, with water leaking onto the subway tunnel below. In 1977, the fountain was shut down.
It sat dormant for decades, and in 2006, the Massachusetts Bay Transportation Authority filled it with boards and concrete, sealing the covered platform with a cap designed to last for about five years.
Earlier this year, Galvin had his crew put up bike racks around the section of the plaza that needed to be reinforced. He said his crew members have driven over it, and people walked along it during smaller events.
But Galvin said he decided to take action when Boston Calling officials, preparing to kick off their event, asked that the bike racks be removed to make room for crowds. With the plaza hosting bigger events, including an upcoming Puerto Rican festival, Galvin said he decided to do the repairs.
“They did not tell me to fix it,” he said. “I took it upon myself as the commissioner of property and management to take the liberty and do it. When I look at the schedule, it’s just back to back to back. Big Apple Circus leaves, and in comes Boston Calling. They leave, and I’ve got the Scooper Bowl.”
Galvin had a tent erected, hired a crew from Classic Contracting, and agreed to pay more than $20,000. Workers reinforced the platform and put caulking around the surface of the defunct fountain.
Meghan Irons can be reached at Meghan.Irons@Globe.com. Follow her on Twitter @ MeghanIrons.
Correction: Because of incorrect information provided to the Globe, the City Hall Plaza contractor was incorrect in an earlier version of this story. The work was done by Classic Contracting.