New pump station should ease Airline flooding in Destrehan

Published 12:00 am Wednesday, November 30, 2011



DESTREHAN – State and local officials in St. Charles Parish recently cut the ribbon on vast improvements to parish hurricane protection that will prevent storm surge from pushing into homes and business on the east bank.

A little more than a year after breaking ground, the parish hit the switch on the recently completed $19 million Cross Bayou Pump Station.

The structure, which is situated along Airline Highway between St. Rose and Destrehan, is designed to pump up to 1,300 cubic feet of water per second over the newly raised St. Charles LaBranche levee and out into the wetlands.

“This is among the single most important public works projects in St. Charles Parish,” said state Sen. Joel Chaisson II, who represents the area. “This is not only protecting homes and businesses, it will also help to keep Airline clear as an evacuation route out.”

Parish officials said the diesel-powered pumps will play a vital role in keeping water from pooling and stagnating along Airline Highway, which has been prone to flooding during periods of heavy rainfall. A period of torrential rain in December 2009 kept Airline Highway at Ormond Boulevard underwater for several days.

Parish President V.J. St. Pierre said the pumps got a good test in September when Tropical Storm Lee dumped several inches of rain in the region. He said the pumps worked efficiently to keep water off Airline as heavy rain passed through.

The project was a joint venture between the Pontchartrain Levee District, which contributed $6.3 million, and the state Department of Transportation and Development, which contributed $7.3 million. The project also got a boost from Motiva Enterprises LLC and Shell Chemical LP, which contributed about $2.5 million for construction, even though their plants in Norco do not benefit directly from the drainage improvements.

The pump station was part of an extensive flood control feasibility study conducted by the Pontchartrain Levee District and completed in March 2009. The pump station is the second of five new pump stations planned for the east bank. The smaller Trepagnier pump station in the Bonnet Carre Spillway was completed in 2004.

The structure is built into the hurricane levee, but it was not part of a $100 million federal project to raise the levee more than 16 feet above sea level, which is up from about 7 feet pre-Katrina, according to Nate Joseph of the U.S. Army Corps of Engineers.

“The improvements are enough to fend off surge from a storm with a 1 percent chance of occurring in a given year,” Joseph said.

Steve Wilson of the Pontchartrain Levee District said the new pump replaces several smaller pumps that are able to gradually lower water levels in the bayou on the dry side of the levee in that area but not enough to make a difference in neighborhoods during heavy rains.

Wilson said the rainwater pumped by the station will help sustain the LaBranche Wetlands, which are losing ground to brackish water from Lake Pontchartrain. The 17,000-acre marsh is considered a valuable buffer zone for the fragile levee system.