Despite widespread flooding and continued rain across Louisiana and Mississippi, New Orleans was, by and large, spared the worst possible effects of Hurricane Barry, which has now been downgraded to a “tropical depression.” However, it’s still early in hurricane season, and there will likely be time to see the results of the $14 billion invested in upgrades to the city’s floodwalls and levees after Hurricane Katrina. The city is also currently engaged in another, more subtle flood-mitigation tactic, but an important one; New Orleans is suing several oil and gas companies over the erosion of coastal wetlands.
Historically, barrier islands have acted as a buffer to Louisiana’s coastal wetlands, reducing the effects waves and ocean currents on the estuaries and wetlands. According to a USGS fact sheet on the Louisiana wetlands, these barrier islands are eroding at an alarming rate, up to 20 meters per year. “As the barrier islands disintegrate, the vast system of sheltered wetlands along Louisiana's delta plains are exposed to the full force and effects of open marine processes such as wave action, salinity intrusion, storm surge, tidal currents, and sediment transport that combine to accelerate wetlands deterioration,” the fact sheet continues. As those in our industry know, barriers that weaken the force of waves and currents are vital to protecting coastlines from erosion. Barrier islands are the first line of defense for the Louisiana coastline, and the coastal wetlands are the second.
“New Orleans has been harmed... The land that's been lost was a protective barrier defending us from hurricanes and floods. If the current trend holds, New Orleans will be a literal coastal city within the next fifty years,” said New Orleans Mayor Latoya Cantrell, US News reports. She says the state could lose over $133 billion in lost capital due to coastal land loss.
There are natural factors—subsidence, the compaction of loose sediment, and erosion from storms, and so on—that have been influencing the loss of land. But human activity has greatly increased erosion. The construction or levees has almost eliminated seasonal flooding that used to provide sediment, and thereby healthy growth, to the wetlands, the USGS fact sheet says. “In addition, throughout the wetlands, an extensive system of dredged canals and flood-control structures, constructed to facilitate hydrocarbon exploration and production as well as commercial and recreational boat traffic, has enabled salt water from the Gulf of Mexico to intrude brackish and freshwater wetlands,” it continues. As Morning Edition put it last month, “the biggest reason [for the loss] is the thousands of miles of channels that oil companies carve through these fragile marshes to get out to their rigs. Those channels have eroded and turned to open water.”
The lawsuit alleges that oil companies did not follow regulations that required they backfill canals, clean up wastes, and repair lost wetlands. In some cases, it says, the companies failed to acquire the required permits to work in the wetlands.
Six other parishes around New Orleans have filed similar suits. The lawsuits will take time, possibly years, to make their way through the courts, and it’s unlikely any money won will be enough to rebuild lost land. But perhaps it will at least encourage a greater awareness of the costs—the ecological, human, and capital costs—of coastal erosion and the value in protecting our coastlines now, before it’s too late.
What value do you see in these lawsuits? What other measures can we take to preemptively protect our coastlines from erosion? Send your comments to firstname.lastname@example.org.