View from the control room of a hopper dredge (Southside Daily photo/Courtesy of Virginia Beach Public Works Engineering)
Sand accumulates in the hopper of a hopper dredge (Southside Daily photo/Courtesy of Virginia Beach Public Works Engineering)
Sand and water are pumped onto the oceanfront beach (Southside Daily photo/Courtesy of Virginia Beach Public Works Engineering)
A hopper dredge, which will be used to gather beach quality sand for the city's oceanfront beaches (Southside Daily photo/Courtesy Virginia Beach Public Works Engineering)
(Southside Daily photo/Courtesy of Virginia Beach Public Works Engineering)
VIRGINIA BEACH — It was announced last week that the city would be on the receiving end of $17.6 million for “re-nourishment” of the beach from Rudee Inlet north to 89th Street.
Although the funding has already been revealed via an emailed announcement from U.S. Sens. Mark Warner and Tim Kaine as part of the Army Corps of Engineers “work plan,” actual work isn’t expected to start until next year.
“Given typical contract preparation and environmental coordination time frames, we expect the project to begin no earlier than spring of 2019,” said Phillip Roehrs, the Water Resources Engineer for the city. “The work will move from south to north, beginning at the pier and moving on to 89th Street as work progresses.”
The last such replenishment work at the oceanfront took place in 2013.
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Re-nourishment, also known as replenishment, involves replacing or adding sand to the beach that has been lost to erosion, which occurs naturally along the oceanfront.
Roehrs said since measurements and documentation began in the 1940s, around 250,000-300,000 cubic yards have been lost each year.
It must be re-nourished constantly, he said, and has been since the 1950s: first via dredge mining during the creation of the Rudee Inlet basin, followed by 40 years of trucks hauling sand, and now open ocean mining using hopper dredges.
“Some argue that it is wasteful, or an inappropriate use of tax funds,” Roehrs said, adding that the tourism industry generates more than $80 million a year in net for the city. “That we spend an annualized average of less than $4 million a year – federal, state, and local combined – to keep the beach healthy could be considered as a benefit-to-cost ratio of 20 to 1.”
It’s not just natural erosion that affects oceanfront areas. Storm damage to coastal communities and their oceanfront homes is also a threat that re-nourishment of the beach can have a positive impact on.
“Preventing the billions of dollars of real estate behind our beach from being damaged by storms, by maintaining a protective beach, and reducing the need for FEMA assistance after storms, is also a major benefit,” he said.
Roehrs said the Atlantic Ocean and Thimble Shoals Channels will be mined for beach-quality sand, in this instance using a hopper dredge, which is a self-propelled ship with dredge pumps and suction arms. Once the hopper dredge has mined the sand and is full, it sails to the oceanfront, connects to a pipeline, and pumps a mix of 80 percent water and 20 percent sand onto the section of beach.
The sand piles up and the water runs back into the ocean. The accumulated sand, he said, is then spread by earth moving equipment to form the beach to a specified dimension.
“Sandbridge also has a federal partnership/cost sharing agreement for periodic replenishment but it is a separate Congressional authority and its funding is separate,” Roehrs said. “Croatan does not have a federal erosion control authority.”
The work will be done by contract, with the vast majority of the funding spent on that contract. A small fraction will be used by the Norfolk District Corps of Engineers on salaries and overhead of their employees who will engage in the project.
“The contractor staffs a ship, a crew of about 10, and a land-based crew of about 10 more employees to manage and shape the sand on the beach, along with management, supervision, safety inspectors, accountants and lawyers,” Roehrs said.