After a report in The New York Times accused Mayor de Blasio of postponing work on a vital water tunnel that the city desperately needs, the mayor announced that construction of the tunnel would begin a year earlier than planned.

Just two main water tunnels currently serve the city, and the Times article explains that construction of Water Tunnel No. 3 "has been regarded as essential to the survival of the city if either of the two existing, and now aged, tunnels should fail."

During his term, Mayor Bloomberg invested $2.7 billion of city money into the $4.7 billion project during his administration, and told reporters at the opening of the Manhattan leg of the tunnel in 2013 (photos above) that "the potential for public health and safety consequences" were significant if the two tunnels didn't have a backup.

The Bloomberg administration projected that the "activation" date for the new tunnel would be 2021. The de Blasio administration says that date never changed, citing a 2013 Bloomberg budget that shows $300 million in construction work slated to begin in 2021 (PDF, page 1745 "SHAFT 17B, SHAFT 18B").

Yet as the Times points out, de Blasio was sensitive to the rising water and sewer rates under his predecessor, and moved money allocated for the tunnel's completion to other projects.

"This work has been deferred because the funding was re-allocated to another, more critical priority—specifically, the damn and dike strengthening of the Ashokan Reservoir," DEP Commissioner Emily Loyd testified at a budget hearing last year [PDF].

"I’m disappointed to hear that they’ve deferred it. It is symptomatic about planning for the future in America," Cooper Union architecture professor Kevin Bone told the Times.

At a press conference today, Mayor de Blasio claimed this was all a matter of accounting, and placed most of the blame on his aides.

"There are times when my team does not do a good job of explaining something, and I think it's as simple as that," he said.

The mayor continued:

We took the money that was scheduled for years up ahead—we put it on hold for a budgetary reason. We didn't think that the estimate was accurate so we pulled it back awaiting a more accurate estimate. I could say very comfortably that probably wasn't the smartest thing to do in terms of showing people the ongoing commitment. But what we did do in the preliminary budget was start to add the money back because we got very specific numbers. So if you look at the preliminary budget, $52 million was now added back to keep things on the 2021 schedule.

To emphasize the point that his administration had done nothing wrong in the first place, de Blasio said he would "accelerate" the construction of the water tunnel by a year.

"[The tunnel is] something we’ve been talking about for the last year—could we find a way to speed it up and we now believe we can do that," he said. "So in the executive budget, the construction date—projected to be 2021 by the Bloomberg administration—will now be 2020. We will move it forward a year and we will add the money into the executive budget to reflect that change."

In unrelated news, De Blasio's $2.5 billion waterfront streetcar system is scheduled to break ground in 2019.