Coastal communities nationwide are ramping up efforts to restore
and protect their shorelines as climate change causes more intense and destructive storms and leads to sea-level rise that puts tens of millions of people at risk. In Alabama, part of focus is in the Mobile County fishing community of Bayou LeBatre.
Louisiana officials canceled a $3 billion project to divert sediment-laden water from the Mississippi River to rebuild part of its coast. But many other projects are underway there and around the country to restore barrier islands, saltwater marshes, shellfish reefs and other natural features that provided protection before they were destroyed by development, industry and efforts to control waterways.
In Alabama, a rebuilt spit of land is shielding a historic town and providing wildlife habitat. In Bayou La Batre, Alabama — a fishing village built in the late 1700s — The Nature Conservancy built breakwaters offshore, then pumped in sediment and built ridges, now covered with vegetation. That created a “speed bump” that has helped protect the town from erosion, said Judy Haner, the Alabama Nature Conservancy’s coastal programs director.
In San Francisco Bay, salt ponds created more than a century ago are reverting to marshland. Along the New York and New Jersey coasts, beaches ravaged by Superstorm Sandy underwent extensive restoration. In Alabama, a rebuilt spit of land is shielding a historic town and providing wildlife habitat.
Coastal communities nationwide are ramping up efforts to fend off rising seas, higher tides and stronger storm surges that are chewing away at coastlines, pushing saltwater farther inland and threatening ecosystems and communities. The need for coastal restoration has been in the spotlight this month after Louisiana officials canceled a $3 billion project because of objections from the fishing industry and concerns about rising costs. The Mid-Barataria project was projected to rebuild more than 20 square miles (32 square kilometers) of land over about 50 years by diverting sediment-laden water from the Mississippi River.
But work continues on many other projects in Louisiana and around the country, including barrier islands, saltwater marshes, shellfish reefs and other natural features that provided protection before they were destroyed or degraded by development. Communities are also building flood walls, berms and levees to protect areas that lack adequate natural protection.
The work has become more urgent as climate change causes more intense and destructive storms and leads to sea-level rise that puts hundreds of communities and tens of millions of people at risk, scientists say.
“The sooner we can make these coastlines more resilient the better,” said Doug George, a geological oceanographer at the National Oceanic and Atmospheric Administration.
In the U.S., perhaps nowhere is more vulnerable than the hurricane-prone Gulf Coast. Louisiana alone has lost more than 2,000 square miles (5,180 square kilometers) of coastline — more than any other state — over the past century, according to the U.S. Geological Survey. Historically, sediment deposited by the Mississippi and other rivers rebuilt land and nourished shore-buffering marshes. But that function was disrupted by the construction of channels and levees, along with other development.
The dangers were magnified in 2005 when Hurricane Katrina breached flood walls and levees, submerging 80% of New Orleans and killing almost 1,400 people — followed closely by Hurricane Rita. Afterward, the state formed the Coastal Protection and Restoration Authority to lessen risks from storm surges and stem land loss.
Most of the almost $18 billion spent in the past 20 years was to shore up levees, flood walls and other structures, the authority said.
Dozens of other projects are completed, planned or underway, including rebuilding marshes and other habitat with sediment dredged from waterways and restoring river flow to areas that have lacked it for years. On Louisiana’s Chandeleur Islands, a barrier island chain, the state will pump in sand to help rebuild them, which will dampen storm surges and benefit sea turtles and other wildlife, said Katie Freer-Leonards, who leads development of the state’s 2029 coastal master plan.
The authority is digging a channel to allow water and sediment from the Mississippi River to flow into part of Maurepas Swamp, a roughly 218-square-mile forested wetland northwest of New Orleans that has been “dying for over a century” because of levees, project manager Brad Miller said. Sediment dredged from elsewhere also has been pumped into thousands of acres of sinking marshes to nourish them and raise their levels.
The same is happening in other states.
The conservancy and others also have been creating miles of oyster reefs, and are acquiring tracts of land away from the coast to allow habitats to move as seawater encroaches. Such efforts won't prevent all land losses, but in Louisiana, “cumulatively, they could make a big difference," said Denise Reed, a research scientist who is working on Louisiana's coastal master plan. “It could buy us some time.”
