Ascension beginning two major drainage projects Ascension beginning two major drainage projects David J. Mitchell| River Parishes bureau Aug. 15, 2011 Comments GONZALES — More than 30 years after Amite River floods swamped eastern Ascension Parish, the parish is now embarking on the second major leg of flood-control projects financed solely with local funds. The idea is to build a series of levees, floodgates and pump stations running along the parish’s eastern edge to protect against flooding from the Amite River and against storm surge from Lake Maurepas. The first major element of the plan was installed in April 1991 – the massive pump station in the McElroy Swamp near Sorrento. Two decades later, the $38 million second phase involves adding a long-awaited levee, floodgate and pump station at Henderson Bayou near Galvez and expanding the capacity of the Marvin J. Braud Pumping Station in the McElroy Swamp. Still to come over the next few years are an extension and an upgrade of the Laurel Ridge levee in the St. Amant area. But project delays — and the lack of a federal cost-benefit analysis — have fueled criticism from some that the projects are too expensive, unnecessary or may cause more problems than they are designed to cure. The Henderson Bayou and Marvin Braud projects, as well as the Laurel Ridge Levee improvements, are being funded through $61.2 million in proceeds from 40-year bonds. The debt, authorized in 2007, is to be repaid from revenue from a half-cent sales tax and a 10-year, 5-mill property tax that voters renewed on Oct. 4, 2008. Both taxes are dedicated to drainage and collected across the entire east bank. The sales tax, which voters approved in September 1984, is perpetual. Project design The Henderson Bayou and Marvin Braud projects in many ways have opposite functions. The Henderson Bayou project will have a 1,100-foot-long, 14-foot-high levee and a floodgate. The structure is designed to stop backwater in the Amite River from flowing upstream into Henderson Bayou and flooding the Galvez area during a 10-year event. Nearly 17 miles of roads and 481 homes and other structures should be protected. The expansion of the Marvin Braud station will add a sixth pump and set up the bay for a future seventh pump. The diesel-fueled station’s existing five pumps are the beating heart of East Ascension drainage. They pull rainfall from a 76-square-mile region, including Gonzales, and push water into the swamps of Lake Maurepas and Blind River. The pump station expansion was prompted in 2005 when all five pumps barely kept up with the heavy rainfall from Hurricane Rita. But the concepts for the Marvin Braud station and the Henderson Bayou floodgate go back further. They are an outgrowth of floods throughout the Amite River Basin during the 1970s and early 1980s. The last of those major floods, in April 1983, remains a flood of record. Water inundated 357,000 acres, 5,300 homes and 200 businesses in six parishes and caused $172 million in damage, a 1992 U.S. Army Corps of Engineers report says. Ascension Parish saw $20.4 million in damage. One outgrowth of the flooding, the still-unfinished Comite River Diversion Canal, should provide some protection to Ascension’s east bank. The $193 million canal will send water from the Comite River to the Mississippi River between Baker and Zachary. The Comite is part of the Amite River Basin, and the canal is expected to lower Amite major flood waters by 6 inches in northern Ascension. The Comite project is at least six to seven years from being finished, said Dietmar Rietschier, executive director of the Amite River Basin Commission. The project is being funded with local property taxes to match state and federal tax dollars that have been slow in the coming. Those floods also prompted the formation in the late ’70s of the Sandbaggers. Led by the late Police Juror Marvin J. Braud, Willard Cointment, Mitchell Epps and others, the homegrown advocacy group pushed the Ascension Parish Police Jury to fund projects locally, avoiding some corps entanglements and its required cost-benefit analyses. The effort led to the half-cent sales tax and a drainage plan by Prescott Follett and Associates Inc. that laid out, in 1982, essentially what drainage officials now will soon build. “The major reason for the funding and doing it ourselves was that we didn’t believe that between the state and the Corps of Engineers, they would fund it in a timely manner, and the public was demanding that something be done, and they were demanding that something be done right now,” former Galvez-area Police Juror J. Darnell Martinez said. Still some debate After the Marvin Braud station was built, years of controversy followed over cost-benefits, efficacy and speculated side effects of other projects in the Follett plan. The corps has never done a cost-benefit analysis on the Henderson Bayou floodgate or the Marvin Braud pump station because no federal funds are involved in the projects, corps spokesman Ricky Boyett said. But the parish has its own analysis on the proposed extension of the Laurel Ridge levee. That analysis found the $10 million shortest and most-direct route is economically feasible, said Jake Lambert, a consulting engineer with GSA. That route, however, would go through White Cypress Swamp. In years past, the corps has favored a route twice as expensive along the swamp’s edge. Parish engineers are looking at a plan to allow water to flow into swamps behind the levee during normal periods. A similar plan helped clear the way with the corps for the Henderson Bayou floodgate. East Ascension Drainage Board Chairman Randy Clouatre said some people have argued the parish should buy out homeowners and businesses in St. Amant. But he noted that some families have been in the area 200 years. “Sometimes the math works out good, and sometimes it doesn’t,” he said of cost-benefit reviews. “Sometimes, you got to do what is right for the people.” Waiting for the next flood The Amite River Basin has seen a drier-than-average period in the past five to seven years, said Karin Gleason, National Climate Data Center meteorologist. George Arcement, director of the U.S. Geological Survey, Louisiana Water Science Center, said he believes the wet periods will return, but it is not clear what flooding will happen, because of urbanization and other changes in the basin since 1983. Some residents worry about unintended effects of the Henderson Bayou floodgate, which is designed to protect against serious, but not the worst, backwater flooding. “I believe if they build that floodgate, they’re going to flood my butt,” said Jimmy Villar, 60, who lives off La. 431 along a part of Henderson Bayou known as Lake Villar. Parish officials last year had Gulf Engineers and Consultants Inc. analyze whether the floodgate would create downstream flooding by preventing Henderson Bayou from storing water in the Amite River. GEC reported a closed floodgate would not cause downstream flooding in most cases, even when its two pumps run. Roux noted the 2,200-square mile Amite River Basin is large enough to handle any water the floodgate would block from flowing up Henderson Bayou. Parish Councilman Dempsey Lambert, who represents Galvez, said the parish study answered Villar’s concerns. Lambert, 45, said he was a St. Amant High student during the 1983 flood, when the National Guard had to rouse him to get him out of the house to safety. “This project should have been completed. This is 25 years later that we finally finishing up with this,” he said. For the long-term East Ascension drainage and Pontchartrain Levee District officials have their eyes on tying the future parish system to the long-planned federal West Shore Levee project. That connection, which is pending congressional approval and funding, would cover the southernmost part of Ascension Parish’s eastern flank. The West Shore Levee is in a multi-year analysis phase, said Marti Lucore, corps senior project manager. Four routes for the levee, which would extend east to the edge of the Bonnet Carre Spillway in St. Charles Parish, are under review. One route ties into the Marvin Braud station in Ascension Parish and is the locally preferred route, but Ascension is not part of the congressionally set study area. Steve Wilson, president of the Pontchartrain Levee District, said that route was added as a tie-in point after Hurricane Katrina in 2005 to protect Interstate 10 from flooding. “Ultimately, if they (the corps) come back and say, ‘Steve, this is a viable option,’ I am going to go back to Congress and say, ‘I need to add this because this is where I am ending my levee,’” Wilson said.