This article first appeared in the August 2006 issue of the Louisiana Sportsman Magazine and is reprinted here by permission.
This article won First Place in the Louisiana Outdoor Writers' Association
Excellence in Craft Competition in the Coastal Restoration Category in for 2007
Terrebonne’s Natural Defenses Nearly Gone
By Wendy Wilson Billiot
After flying over lower Terrebonne Parish recently, debates over gaited canals and the rush to catch specks before they head to the Gulf to spawn just don’t seem very important. The images seen from the cockpit of that Cessna 172 should be burned in the mind of every U.S. citizen and decision maker who holds the future of coastal Louisiana in his hands. Those images are of miles of open water where marsh once thrived and thin ribbons of land where pastures used to be.
The degradation of the barrier islands is unbelievable. The Isles Dernieres chain, once Terrebonne Parish’s first line of defense against hurricane storm surges, has eroded away to skinny strips. In its current condition, this chain of disconnected sandbars offers little or no protection against tidal surge.
The once mile-wide island looks no more than a football field wide from the air. Hurricanes have cut through the island making it a chain of islands on the brink of extinction. As the pilot pointed out, the islands are now barely a speed bump for the likes of hurricane-related storm surges.
One has only to look at the flooding caused by a measly nine-foot tidal surge associated with Hurricane Rita in 2005 to know this is true. Rita made landfall 150 miles to the west of this parish but still caused rising waters that flooded homes and businesses in several bayou communities south of Houma.
In its prime, the Isles Dernieres chain could have reduced Rita’s tidal surge by several feet. In reality, the chain of eroded islands between lower Terrebonne Parish and the Gulf of Mexico is no longer capable of reducing the height or strength of even a minor tidal surge. This parish’s first line of defense is compromised, which leaves citizens to their second line of defense – the marsh.
Marshland serves a vital roll in determining whether anyone will continue to camp or reside south of Houma without flooding again. “Healthy marsh acts as a buffer zone, like a huge sponge soaking up water from hurricane-driven waves,” explains Susan Testroet-Bergeron, education coordinator for the Barataria-Terrebonne National Estuary Program. An older Army Corps of Engineers study states that for every 2.7 miles of healthy marsh, one foot of tidal surge is absorbed.
That means it would have taken roughly 27 miles of healthy marsh to absorb Rita’s 9-foot surge, but this marsh no longer exists. Houses 15 to 20 miles north of the Gulf flooded as much as 4 feet.
If it isn’t enough that this parish no longer has protection from either barrier islands or healthy marsh, add the Houma Navigation Canal (HNC). Completed in 1962, this channel was originally 150 feet wide but today is said to be 800 feet at its widest. Analogous to the Mississippi River Gulf Outlet, the HNC led Rita’s tidal surge all the way up to the Gulf Intracoastal Waterway and over its banks in parts of Houma, flooding every low-lying area along the way with salt water.
Captain John Verret, a charter fisherman and life-long resident of Bayou DuLarge, says what the marsh needs is dirt. “I have spent much of my life in the marshes here,” he said. “The changes I thought would take a century have happened almost overnight. Where I once walked, I can now swim. I now catch reds and specks where I used to catch bass and perch, and I’m only 40 years old. So, call it mud or call it soil, it doesn’t matter. In order to rebuild the marsh, you must have dirt.”
The geologists call it sediment, and roughly 300,000 cubic feet of it drop off the Continental Shelf every day. However, a proven method of transporting those sediments into starved wetlands hovers on the horizon.
“Pipeline sediment transfer” is the buzz phrase among restoration advocates. More commonly called “pipeline slurry sediment delivery”, this method was successfully implemented in restoring the LaBranche Wetlands near New Orleans in 1994. In this case, the sediment was dredged from the bottom of Lake Pontchartrain and transported through a 7,500-footlong pipeline to the degraded wetland area. In just four weeks, nearly 2.7 million cubic yards of sediment were transported to create approximately 300 acres of land. In 2005, approximately 400 acres of new land was formed on Timbalier Island using sediment dredged three miles offshore and pumped to the island.
So, what are we waiting for?
Money. Currently, the state receives less than one percent of its offshore Outer Continental Shelf (OCS) oil royalties, or about $32 million in 2005. Our congressional delegation is currently fighting for us to get a larger share.
Louisiana generates $5-$7 billion in oil and gas revenues every year. Thirty percent of the nation’s oil and gas flow through here. The Port of South Louisiana, with exports of 52 million tons of cargo a year, is the largest tonnage port district in the Western Hemisphere. Our state produces 30 percent of all seafood in the continental U.S., but how long will that productivity last? Forty percent of all tidal marshes in the continental U.S. are located here, while 90 percent of all coastal marsh loss in the nation occurs here. All of these vital resources are directly supported and protected by our rapidly eroding wetlands.
With future OCS revenues in the potential range of $4 billion annually, that would fund the creation of about 600 million acres of wetlands.
Wendy Wilson Billiot resides below Houma, Louisiana on Bayou Dularge. Hurricane Rita, the second hurricane to devastate Louisiana in the fall of 2005, flooded her home, which she, family and friends have cleaned up and made livable.
Billiot is the author of a popular illustrated children’s book “Before the Saltwater Came,” which details the loss of the freshwater marsh to saltwater intrusion through the eyes of an old otter named LaLoutre. The book can be reviewed or ordered from its website www.wetlandbooks.com. Billiot speaks to schoolchildren, teaches seminars, offers wetland tours, and hosts forums on wetlands loss in south Louisiana. She may be reached via email at email@example.com