nola.com
If Louisiana wants its expensive coastal restoration projects to last longer and cost less over time, it should seek out a higher quality building material: deep sea sand. That’s the recommendation of a new study that found that the initial higher cost of digging up and transporting sand from the Gulf of Mexico’s Outer Continental Shelf is a better longer-term choice than using the finer, lighter sediment in the Mississippi River and along the coast.
The study simulated a 1,800-acre restoration project made of sand from the Outer Continental Shelf and sand sourced near the coast. After 50 years, about 490 acres of the project built with deep sea sand remained, whereas only 325 acres was left of the project made with finer-grain sediment. Under simulations punctuated by strong storms, the advantages of deep sea sand were even more pronounced, with cost advantages predicted within five years of a project’s completion. The three-year study was conducted with help from Mississippi State University, University of New Orleans and the Water Institute of the Gulf. A large share of the funding came from the the U.S. Bureau of Ocean Energy Management. More here.