Can Millions of Tons of Sand Save a Gas Terminal From the Sea?
(Bloomberg) -- On the evening of Dec. 5, 2013, the U.K. east coast was battered by the worst storm surge in 60 years as the North Sea rose more than 2 meters (6.6 feet) above normal.
The massive flow of water beat sea defenses in the county of Norfolk, one of the worst hit areas, and traveled down roads to flood almost 200 homes and businesses. Not only did it force some residents in the villages of Bacton and Walcott to flee their properties — it also took a big bite out of the land that protected a very important part of Britain’s energy infrastructure from falling into the sea.
As the storm raged and the waves hit, more and more of the land beneath the Bacton natural gas terminal disappeared. Over 48 hours, the erosion was so bad that 10 meters of cliff vanished, leaving just 15 meters of land between the facility and the sea.
After another five years of deterioration and damage to the coast line, a search for the optimal protection settled on sand. And lots of it. Options from concrete to rocks were also explored. Work began this month and the plan is to pump 1.8 million cubic meters of sand, enough to fill one and a half London’s Wembley Stadiums, onto a six-kilometer stretch between the Bacton terminal and Walcott. About half of it will be in front of the terminal.
Out at sea, the 227-meter long Ham 318, a vessel deployed by Van Oord NV, is making three to four trips a day to Bacton. The ship, a trailing suction hopper dredger, takes sand from offshore areas near Great Yarmouth, south along the coast, without leaving any holes in the seabed. Every load brings ashore about 20,000 cubic meters of material. When the vessel is in position about a kilometer out at sea, it connects to a floating pipe, which is linked to a second conduit onshore. A mixture of sand and water is pumped onto the beach, as shown in the photo above.
“You would see on normal high tide the water would actually lap against the cliffs, and that is not going to happen anymore now,” said Jaap Flikweert, flood and coastal management adviser at Royal HaskoningDHV, the Dutch company that designed the rescue project. It has been named sandscaping, the first of the kind in the U.K., and will give the terminal from 1968 another 15 to 20 years of protection.
