Coastal erosion message locally

Decades old technology could help slow the Gulf of Mexico’s annual 26-square-mile chomp at Louisiana’s coast, the head of the Barataria-Terrebonne National Estuary Program said.

“If you don’t hunt or fish, don’t like birds, if you stay in your house all day, you still rely on wetlands,” Estuary program executive director Kerry St. Pe told a joint lunch meeting of the New Iberia Optimist and New Iberia Rotary clubs Wednesday.

He said coastal marshes and barrier islands that used to knock down storm surges have been washing away due, in part, to choking off the replenishing sediments from building levees along the Mississippi River and haphazard digging of canals for oil exploration. Hurricanes would bring in strong winds and rain, but surges were kept at bay.

Evidence from hurricanes Katrina and Rita in 2005 and Gustav and Ike in September show how devastating the storm surges can be without the wetlands.

“This is not something that’s happening over generations, it’s happening in 10 years,” St. Pe said.

The Estuary program’s board of people from numerous state agencies and private business associations have decided the state’s coast must be saved, but St. Pe said many now argue what’s the best way to do it. He said the best way to build land is to use the same dredging method that was used to build English Turn Golf Course in New Orleans and several roads where massive amounts of dirt are needed: harvesting the sediments from the Mississippi and Atchafalaya Rivers and piping it to places where now sunken ridges can be rebuilt.

St. Pe said the U.S. Army Corps of Engineers, for example, dredges 22 million cubic yards of sediment each year from the Mississippi River to keep it navigable. That sediment is now dumped into the Gulf. He estimates that up to 400 square miles of wetlands and ridges can be rebuilt in 50 years, but it comes with a hefty price tag of more than $600 million per year.

The Barataria and Terrebonne basins form an elongated triangle from the Mississippi River to the Atchafalaya and north to where the rivers separate. It is the area of the state that is eroding the fastest, an estimated 19 square miles per year.

Louisiana’s coast west of the Atchafalaya, however, is not immune. One has only to look at communities along St. Mary, Iberia and other parishes west to the Texas state line during hurricanes Rita and Ike.

St. Pe said using sediment from the Atchafalaya River would not negatively impact the Atchafalaya Basin and could help. Using some of the river’s sediment to build land elsewhere could ease some of the silting problem that some crawfishermen have complained about.