This story initially appeared on Grist and is a part of the Climate Desk collaboration.
When governments discover themselves combating the specter of coastal erosion, their default response tends to be fairly easy: If sand is disappearing from a seashore, they pump in additional sand to exchange it. This technique, often called “beach nourishment,” has develop into a cornerstone of coastal defenses world wide, complementing laborious buildings like sea partitions. North Carolina, as an illustration, has dumped greater than 100 million tons of sand onto its seashores over the previous 30 years, at a price of greater than $1 billion.
The drawback with seashore nourishment is apparent. If you dump sand on an eroding seashore, it’s solely a matter of time earlier than that new sand erodes. Then you might have to do it over again.
Beach nourishment tasks are supposed to final for round 5 years, however they usually disappear sooner than anticipated. Moreover, an enormous coastal storm can wipe them out in a single night time. And the prices are staggering: Dragging in new sand requires leasing and working enormous diesel dredge boats. Only the wealthiest areas can afford to do it 12 months after 12 months.
Now, after many years of reliance on repeated seashore nourishment, a brand new technique for managing erosion is exhibiting up on coastlines world wide. It’s known as the “sand motor,” and it comes from the Netherlands, a low-lying nation with centuries of expertise in coastal safety.
A “sand motor” isn’t an precise motor—it’s a sculpted panorama that works with nature slightly than in opposition to it. Instead of rebuilding a seashore with a fair line of latest sand, engineers lengthen one part of the shoreline out into the ocean at an angle.. Over time, the pure wave motion of the ocean acts as a “motor” that pushes the sand from this protruding landmass out alongside the remainder of the pure shoreline, spreading it down the shoreline for miles.
While sand motors require rather more upfront funding than regular seashore nourishment—and lots of instances extra sand—in addition they defend extra land and final for much longer. Developed international locations such because the Netherlands and the United Kingdom are turning to these megaprojects instead to repeated nourishment, and the World Bank is financing a sand motor in West Africa as a part of a billion-dollar adaptation program meant to struggle sea-level rise. But these large tasks solely work in areas the place erosion is just not but at a crucial stage. That means they’re unlikely to present up within the United States, the place many coastal areas are already on the purpose of disappearing altogether.
The thought for the undertaking got here from a Dutch professor named Marcel Stive, who had watched with frustration as his nation’s authorities spent billions to nourish the identical coastal areas again and again as sea ranges saved rising. Stive offered the thought to the federal government, which employed a big dredging firm known as Boskalis to construct a prototype on the shoreline south of The Hague.
Even this experimental undertaking, which the Dutch name “de Zandmotor,” was an unprecedented enterprise. Boskalis dredged up round 28 million cubic yards of sand from the ocean flooring—greater than the Netherlands makes use of on nourishment tasks nationwide in a given 12 months. Engineers then sculpted the sand right into a hook that curved eastward alongside the shore, making certain that waves would push the sand northeast towards seashores close to The Hague. They additionally created a lagoon in the course of the sand construction in order that locals wouldn’t have to stroll for nearly a mile to get to the water. In the years since Boskalis completed development on the $50 million undertaking, the hook of sand has flattened out, nearly the way in which a wave breaks because it reaches the shore.