GONZALES — Expansion of a key pump station that drains a large swath of East Ascension is getting the final touches and will be ready when hurricane season starts June 1, Ascension Parish officials said.

Underway since August 2011, the $13.3 million expansion is adding a sixth pump and the bay for a future seventh pump to the massive Marvin J. Braud Pumping Station in the McElroy Swamp in southeast Ascension.

The station’s existing five pumps can move 5,000 cubic feet per second of water and drain a 76-square-mile area that extends into Gonzales and southern Prairieville.

With residential development in Ascension and severe events, though, the station’s pumps have increasingly been put to the test, including the heavy rains of Hurricane Rita in 2005 and last year during Hurricane Isaac.

Last week, the East Ascension Consolidated Gravity Drainage District No. 1 Board of Commissioners held off on granting substantial completion for the project because of technical issues that popped up recently.

Bill Roux, East Ascension drainage director, said Thursday the station would “absolutely” be ready for hurricane season and is ready now if needed.

“Something this big, you always got little things all over the place you’ve got to iron out, but it’s nothing unusual and nothing major,” Roux said in an interview.

Among the issues to be resolved are problems with sensors on the new pump’s diesel-powered engine. Roux said the sensors make sure the engine is ready to be engaged to turn the pump impeller that moves water out.

During last week’s drainage board meeting, Henry Picard III, vice president of Burk-Kleinpeter Inc., the engineering firm handling the project, described the sensor problem as “a minor glitch” that workers were able to bypass recently to run the pump and show how it operates.

He said workers had been trying to resolve the sensor problem before the meeting but weren’t able to get it fixed by then.

“We just want to make sure it’s done right so it can be run the way it should be,” Picard said.

Parish President Tommy Martinez and some drainage commissioners directed Picard and Roux to check into the status of the new equipment’s warranties.

Roux said the company that installed the electronics is expected out this week and that substantial completion, a formal sign that construction is largely done, could be approved as early as Thursday in a special board meeting.

Roux said that would start the clock for contractor Max Foote Construction Co. Inc. to collect the final 10 percent of its payment from the parish, pending a final list of fixes called the punch list.

The pump station expansion is one of two major East Ascension drainage works underway during the past two years.

They are being paid for with $61.2 million in proceeds available from 40-year bonds authorized in 2007. The parish’s existing half-cent drainage sales tax and a 5-mill drainage property tax back the bonds, which did not require voter approval.

Where the Marvin Braud station is designed to drain water from Ascension, the $15.6 million Henderson Bayou floodgate is designed to keep water from entering Ascension.

Once built, the floodgate, which also includes a 1,100-foot-long, 14-foot-high levee and two small pumps, is designed to prevent flooding on the Amite River from moving upstream into Henderson Bayou and flooding northeast Ascension.

That project is not expected to be finished until December or January.