Winnipeg's mishandling of a multimillion-dollar lawsuit over its water-treatment plant is inexcusable, Mayor Brian Bowman said as he backed up the chief administrative officer's decision to dismiss a city lawyer over the incident.

A lawsuit over the construction of Winnipeg's $300-million water-treatment plant ended last week, when lawyers for the defendants pointed out the city missed a six-year limitation period to launch legal action over alleged construction deficiencies.

The city now has no means of recovering up to $20 million in costs related to repairing structures that have suffered from leaks, heaving roofs, failing generators and explosions.

None of the problems affect primary water-treatment processes, but they still must be fixed in the future, chief administrative officer Doug McNeill said Monday.

The lawyer responsible for what McNeill called a "huge error" has been held accountable and has been terminated with cause, Bowman said Tuesday.

"It's obviously inexcusable that this kind of mistake would be made and taxpayers are ultimately affected as a result. We're not happy, obviously," the mayor said outside his office at city hall. "It's a significant mistake that nobody wants to see."

The mayor said the public service this council inherited was dysfunctional and praised changes made by McNeil, which include new directors in several departments.

"Clearly more work needs to be done," Bowman said.

Lawsuit over water treatment plant dries up after lawyer misses deadline1:55

Other members of council reacted with more dismay.

South Winnipeg-St. Norbert Coun. Janice Lukes said lawyers do not work alone and she wants to know what the city's director of legal services, Krista Boryskavich, has to say about the error.

Lukes also said she was led to believe the city hoped to recover up to $30 million, not $20 million, from the failed lawsuit.

North Kildonan Coun. Jeff Browaty said he was led to believe the city was going to launch a lawsuit related to the decision to use a chemical at the water-treatment plant that had exacerbated the instance of brown water in the city's pipes.

"I have an email from the city solicitor that indicates it never happened," he said in a statement.