Hurricane Katrina, which left approximately 1,500 dead in Louisiana and 80% of New Orleans underwater was a preventable, manmade disaster caused by a failed levee system. But before the storm even hit the levees that surround New Orleans, it passed through a once-rich swathe of coastal wetlands–a natural guard against hurricane-strength storm surge–that is disappearing at a rate of a football field every 48 minutes.
Coastal land loss is the biggest existential issue facing this region today and experts warn that without significant intervention, southern Louisiana will be underwater in as little as 50 years. Canals dredged by the oil and gas industry and levees along the Mississippi that block the flow of sediment to the region have seriously degraded land volume, while climate-change-driven sea level rise is helping to swallow whole towns within our lifetimes.
Today, authorities in Louisiana are scrambling to muster the resources for a massive proposed $50BN plan to shore up the state’s sinking coastline. Meanwhile, in classic Louisiana DIY fashion, local entrepreneurs, inventors and ecologists are working outside the bureaucracy to jumpstart simple solutions to this complex problem. Here are a few that are getting their hands dirty for coastal restoration.
Webster Pierce, a 74-year-old Louisiana native, has seen coastal erosion first hand. Growing up near the town of Cut Off, where he still lives today, the area used to be “marshland as far as the eye could see. I used to hunt rabbit, duck and deer,” he said. “And now all you have is water.”
Pierce–who has worked as a science teacher, a cattle farmer, in the oil industry and once managed a levee protection area–decided to take matters into his own hands. In 2009, he started prototyping what he now calls the “Wave Robber” in his back yard with store-bought materials. A cross between a sea wall and a filter, the Wave Robber looks like a set of stairs surrounded by a fence. The angled shield at the front–inspired by WWII Russian tank designs, which were built at an angle to deflect bullets–breaks the energy of the wave, while built-in piping allows valuable sediment to flow through and settle on the shoreline behind. The entire unit, which measures around 10 feet across at the front-end and 30 feet wide at the back, is anchored to the sea floor by filling the bottom of the unit with water, which can then be pumped out when the unit is ready to be moved.
What started as a humble backyard experiment is now being tested as a potentially scalable solution to coastal erosion by a team at the University of Louisiana at Lafayette. In 2010, Pierce and Dr. Daniel Gang, professor of environmental engineering, won a grant for lab testing, during which they that the Wave Robber blocked 80% of a wave’s energy while allowing 20% of sediment to build up on the banks. Now, Gang and his team are testing the apparatus in the field as part of a multi-year study. Over the last two years, Gang and his team have measured two to three inches of sediment increase by using the Wave Robber, compared to a loss of three inches of sediment in a nearby area where no intervention was installed. Rates of subsidence–the scientific term for the sinking of land–vary widely across Louisiana, but one recent measurement found that one area of the coast lost 1.32 inches of elevation in five years, one of the highest rates in the world.
According to Gang, one of the main advantages of the Wave Robber is that is easy to install and can be easily moved (floated, in fact) to new locations once it’s done its job in one area of the coast. He says it’s more effective than traditional bulwarks against coastal erosion, like rock, which is expensive and needs to be imported into Louisiana. “The Wave Robber is the best choice, especially for the marsh,” said Gang. “That area . . . needs a new solution, a non-rock solution.”
Pierce and Gang planning to install more units in the fall and are looking for grants for additional research. Their ultimate hope is to roll-out the Wave Robber across significant areas of coastline through private-public partnerships. But Pierce is anxious for support and national attention on the issue of coastal restoration.
“We are in desperate need of the rest of the country supporting us to try to restore our marshes,” he said. “I’d like to see more support.”
Since the 19th century, the world has lost about 85% of its oyster reefs, large clusters of oysters attached to each other and underlying rock. This includes many reefs along the shore of Louisiana, where years of over-harvesting of oysters and layers of shells on the seabed floor (for construction materials) and the ongoing effects of the BP oil spill have taken their toll. Oyster yields in parts of Louisiana’s once flourishing trade have dropped by over two-thirds between 2009 and 2013. The dwindling reef habitats and oyster population have not only made a huge dent in the local oyster industry but has also, because oyster reefs are like the local equivalent of coral reef, left Louisiana’s coastline more vulnerable to large waves and storm surge.
Tyler Ortego, founder of Ora Estuaries, is using “oyster engineering” to kill two birds with one stone: rebuild the oyster population while restoring the habitat that helps protect coastal land and soften storm surge. The secret ingredient of their OysterBreak reef system is a proprietary concrete mix that they call Oystercrete, which has a microscopic texture that allows the wild oyster larvae naturally present in the Gulf to easily attach and start growing. The modular “Olympic ring” design of OysterBreak, its creators say, gives more space for fisheries to flourish, breaks the energy waves crashing on shore, and allows installation to be easily scaled up or. The ring design also covers less area on the ocean floor than traditional artificial reefs, which use large rocks shipped in by barge from the interior of the country, and often require dredging to get in place.
The real advantages of OysterBreak start to show over time, though, says Ortego, when oysters grow to fill in the gaps between the rings, effectively “gluing” the entire structure together with a super-strong bond (one study by an LSU student found that a two-year-old oyster attachment required 20 times the breaking force of a slice of concrete).
“We’re making the skeleton and we’re letting the oysters do the rest of the work,” said Ortega.
Working with Wayfarer Environmental Technologies, a Louisiana engineering firm, the Ora Estuaries team has contracts with a few local governments around Louisiana and currently has about three miles total of OysterBreak installed at various sites in brackish marsh water close to the shoreline. They are reporting sediment build-up of as much as 16 to 20 inches in some areas. They plan to start working in Mississippi and Alabama on projects that involve the Army Corps of Engineers (ACE). Getting the blessing of the ACE, which Mike calls the “captains of the waters” will be crucial in moving toward wide-scale implementation.
“Everybody tends to overthink things and want to get fancy and want to get expensive,” said Mike Turley, an engineer at Wayfarer who also worked on coastal erosion in the Chesapeake Bay for several years. “It always comes down to usually the simplest solution is the best, and typically the most cost-effective when you have a huge task ahead of you.”
Many of Louisiana’s cypress swamps, a valuable hurricane safeguard, are dying off due to excessive logging and saltwater intrusion (mainly from canals built by oil and gas companies drilling in the area), among other factors. But re-planting forests is a slow-going job, both because of the time required for a tree to grow to maturity and the arduous planting process in swamp conditions. Over the past few years, Gary Schaffer, a wetlands restoration policy advisor and professor at Southeastern Louisiana University, and his wife and partner, Demetra Kandelpas, an expert in wetland plant ecology, have found two novel ways to speed up restoration: nutrient-rich wastewater and decomposable grow shelters.
Kandelpas says nutrients, like the nitrogen and phosphorus found in irrigation water runoff and wastewater, get a bad rap because of their role in causing dead zones in the Gulf, which cause algal blooms and kill wildlife. “Dead zones are known but people are taking the theory into the extreme and believe that you can’t dump nutrients anywhere,” she said. “The swamps in Louisiana are so nutrient-starved.”
As part of a pilot project in Hammond, LA, their company, Wetland Resources, has been redirecting the city’s secondarily-treated wastewater (after pathogens and solids are removed) to nearby wetlands. The process, says Kandelpas, not only saves cities money by skipping the last stage of wastewater treatment, but also improves the growing conditions trees and plants.
The second part of Wetland Resources’ business is protecting young saplings and streamlining the planting process. Under current methods, cypress saplings are grown in a nursery in a pot and then transported to the swamps to be put in the ground and wrapped with plastic to protect the roots from nutria, an area pest known to destroy hundreds of acres of cypress swamps in a single night. But planters are limited by the number of pots they can fit in a trailer to bring out to a site on each trip, and this process is generally a two-person job.
Kandelpas and Schaffer designed a biodegradable grow shelter–an all-in-one plant pot and nutria guard–that allows saplings to skip the nursery altogether and be planted directly in the wetlands. Because of its smaller size, grow shelters can be planted faster and only require one person, cutting down on labor costs, a major expense in restoration work. According to Kandelpas, these trees can also mature as much as five years earlier than trees transferred from a nursery, especially when growing in nutrient-rich waters.
Kandelpas and Schaffer are currently working to expand their reach and get cypress restoration plans into the state’s master plan, and they hope to plant hundreds of thousands of trees across southern Louisiana over the next decade. But shifting the conversation on nutrients and wastewater use has been an uphill battle.
“If we change the thinking,” said Kandelpas, “if we could just get some of that wasted water, a lot of which is going into the Mississippi River and the Gulf and causing algae blooms, if we could just divert that into the wetlands, we can have a win-win situation for municipalities and coastal restoration.”