SAN FRANCISCO, CALIFORNIA — I think exploring ideas on how the Netherlands and Louisiana designed climate change adaptation strategies could be a model for Dumaguete’s reclamation and shoreline protection.
Like Dumaguete, both areas sit on low-lying river deltas, and are increasingly apprehensive of sea level rise. Climate change has worsened storms on the North Sea that can push waves into Netherlands’ densely-populated areas. And yet, it’s no comparison to the roaring hurricanes from the Gulf of Mexico that ravage Louisiana yearly. By the end of the 21st century, Louisiana sea level rise is projected by some high-pollution scenarios to hit four to seven feet.
Following Hurricanes Katrina and Rita in 2005, the Louisiana Legislature created the Coastal Protection & Restoration Authority, tasked to coordinate local, state, and federal efforts to achieve comprehensive coastal protection and restoration.
To accomplish these goals, the CPRA was charged with developing a master plan using the best available science and engineering to sustain the coastal ecosystem, safeguard coastal populations, and promote vital economic and cultural resources.
At a cost of about $2 billion on current sand-moving projects, Louisiana is projected to spend $50 billion in next 50 years for the ambitious restoration and storm protection initiative.
Specifically, the Louisiana coastline initiative is a beach rebuild along the rapidly-deteriorating coastlines of Whiskey Island and Caminada Headland.
On the other hand, while Louisiana’s coastline initiative seeks to restore what was lost, The Netherlands, famous for its network of walls, levees, and sea gates that protect its coast, has piped a $55 million sandscaping project called Sand Motor that pushes sand naturally into places where it will provide coastal protection.
Interestingly, as a spillover effect, it has now turned into a magnet for biodiversity, as well as beachgoers, kiteboarders, walkers, sunbathers, and surfers.
At the 2019 Conference in the Coastal Sediments Series held in Tampa/St. Petersburg in Florida, with the theme Advancing Science and Engineering for Resilient Coastal Systems, the Netherlands’ Sand Motor experience gained much interest.
This is not unusual because more than 75 Sand Motor peer-reviewed studies have been published by scientists from Australia, New Zealand, the Bahamas, and the U.S. with high impact on the coastal science and engineering community.
As the world’s largest experiment in coastal defense, at a time when climate change is causing seas to rise and storms to intensify, it is humming along nicely. It is reported that it has been worn down by the elements, retreating about 1,000 feet between 2011 and 2018. Still, about five miles of nearby coastlines are now coated with a thick buffer of sand and naturally-formed dunes.
According to a report by Delft University, plants and marine life have also adapted. The lagoon has acted as a nursery for fish, tideland for shellfish, and nesting site for at least 40 species of birds.
Also, a spiky beach grass called Marram proliferates there, traps windblown sand, and piles it into shore-toughening dunes.
By design, these shoreline initiatives act as speed bumps, absorbing wind and wave power that would otherwise travel unimpeded into the towns and cities.
Unfortunately, Louisiana is spending more money to move far less sand, compared to The Netherlands. Why?
Well, two things: First are the two maritime laws — the Foreign Dredge Act of 1906 and the Jones Act of 1920 — that effectively banned foreign companies from dredging in U.S. waters. All dredges must be U.S.-built-operated-and-crewed.
Second, the unintended effect of such protectionist policy created a closed market that benefits a few U.S. operators, turning coastal initiatives far more expensive. Many times under single-bid scenarios, companies could typically charge at least twice as much as when four or more other companies compete.
Regardless of the similarities and differences of these two experiments, I think the eclectic approach of the need to utilize science, engineering, and nature to help protect and reclaim the coast is a lesson that can be learned for Dumaguete City’s reclamation and shoreline protection initiatives.
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Author’s email: efren.padilla@csueastbay.edu
