NEW ORLEANS -- A key piece of equipment that powers New Orleans’ beleaguered drainage pumps could finally come back online this month, but only at a reduced capacity and nearly five years after city officials promised it would be fixed.

Turbine No. 4, a 1920s-vintage, steam-powered turbine and generator, is one of only a few like it left in the world. It is designed to supply 20 megawatts of 25-cycle power -- a full third of the unique, old-fashioned kind of electricity the Sewerage and Water Board generates in-house to run its sewer, water-treatment and drainage equipment.

The turbine was initially fixed after being damaged in Hurricane Katrina in 2005, but it couldn’t operate at full power and was taken completely off-line in 2012. Since then, the S&WB has promised repeatedly that it would be repaired shortly, only to encounter problems finding parts or difficulties keeping delicate components calibrated.

At a special S&WB meeting Friday, Paul Rainwater of the board’s emergency interim management team said Turbine No. 4 could be back online by mid- to late-September.

“That timeline could be up or down depending on what’s happening,” Rainwater said.

Before the devastating flash floods of Aug. 5 -- when three of the S&WB’s old-fashioned turbines were not available and a fourth had recently failed – the plan was to have Turbine No. 4 back in service by the end of 2017. After acknowledging the lack of power compromised the system, Mayor Mitch Landrieu said his administration was pushing for a September completion date.

On Aug. 16, WWL-TV asked Landrieu, who is also the president of the Sewerage & Water Board, why the Turbine No. 4 repairs have taken so long.

“That particular (turbine) had to be completely refurbished, not just fixed. And it was in the process of getting fixed,” he said. “It was supposed to be finished in December. So, one of the things we did was ask them to work really hard and move it up to six weeks. It’s not like you can just snap your fingers and move it up three years.”

But the project was never supposed to take more than a year in the first place.

The Sewerage and Water Board entered into a $12.7 million contract in 2011 with Industrial & Mechanical Contractors, and an S&WB operations report written in late 2011 said Turbine No. 4 would be “rehabbed to its full design capacity in by (sic) 2013.”

But every annual operations report that followed said something similar – that Turbine No. 4 would be back online by the following year. More than a dozen change orders tacked another $3 million on to that price tag.

In the meantime, a second contract, funded with $6.7 million in federal Hazard Mitigation grants, was awarded to the same company, Industrial & Mechanical Contractors, to refurbish the generator attached to Turbine No. 4.

The S&WB also approved about a dozen change orders on that contract, adding another $3 million to it.

The total cost of the Turbine No. 4 restoration is now pegged at $24 million, according to an Aug. 6 email by S&WB General Superintendent Joe Becker.

The minutes from years of S&WB committee meetings at which change orders were approved give little to no explanation for why the costs were rising.

Harold Heidingsfelder, president and owner of Industrial & Mechanical Contractors, said his crews ran into numerous problems over the years that he didn’t want to talk about. He did say, however, that he’s hoping Turbine No. 4 will be operational by the end of this weekend, and Rainwater said S&WB operators may be able to start testing it then.

“We’re dealing with some mighty old stuff,” Heidingsfelder said.

Still, even if the turbine is restored this month, it won’t be able to produce the full 20 megawatts of electricity it was designed to generate, city officials said. The contractors are still seeking an extra piece of equipment, but plan to run it below its designed capacity until that item can be added.