A letter from a state environmental agency questioning a plan to save Sandwich’s Town Neck Beach could drastically affect a sand replenishment effort that has taken years to engineer.
The letter sent earlier this month from the Massachusetts Office of Coastal Zone Management to the US Army Corps of Engineers pointed out that the sand on Town Neck is far coarser in quality than the sand that would be taken from a borrow site off Scusset Beach.
This conflicting coarseness, they fear, would cause the finer sand be erode more quickly.
“If all 388,000 cubic yards of sediment needed to nourish Town Neck are taken from the nearshore borrow area, the finer sediments are likely to move and be redistributed faster than if sediments of a similar grain size are used,” wrote Lisa Berry Engler, CZM director.
“If compatible sediment is not used for the nourishment project, it will limit the longevity and protection provided by the nourishment as well as increasing the potential adverse impacts to adjacent eelgrass, shellfish, and other sensitive habitats,” Ms. Engler added.
Town Manager George H. (Bud) Dunham expressed his disappointment and concern in the CZM’s stance last week at a board of selectmen’s meeting. The board did not publicly discuss the letter in depth.
Natural Resources Director David DeConto this week voiced his deep concern over the letter’s potential chilling effect on the Army Corps proposed plan to deposit almost 400,000 cubic yards of sand on Town Neck Beach in the coming years.
“They are saying you need to make sure the sand is compatible, but it’s all coming from the same [sand] source,” Mr. DeConto said in a telephone interview. “We’re not happy.”
“They are also saying they are concerned that taking the sand from Scusset would create a [long-term] hole at the borrow site,” Mr. DeConto added. “We disagree. We believe the sand will fill right back in.”
The main reason the Scusset site was chosen is because sand has amassed there over the years as the stone jetties at the mouth of the Cape Cod Canal—owned and maintained by the Army Corps—diverted that sand from its natural path to Town Neck beach.
The sand starvation over the years, in addition to natural erosion from storms, has led to Town Neck Beach’s severe depletion.
The Army Corps, after years of studying the situation, has recently taken responsibility for much of Town Neck Beach’s lack of sand and is proposing the placement of $12.5 million worth of sand as an immediate remedy.
Before forwarding the plan to its next steps—design and implementation— the Army Corps held a 30-day public comment period that ended the first week of April. The CZM letter was sent to the Army Corps accordingly.
The CZM believes sand taken from upland—or further ashore—from Scusset Beach and/or sand from periodic dredging of the Cape Cod Canal would be coarser and therefore more stable materials for beach renourishment.
“Both alternatives warrant further investigation to assess the additional benefits from using other sources with coarser grain sizes,” Ms. Engler wrote. “The current analysis [by the Army Corps]…did not appear to consider the increased longevity associated with using a coarser grained source of sediments, and the impact to sensitive environmental resources was not identified.”
The CZM recommends that only 224,000 cubic yards of sand be taken from the offshore Scusset borrow site.
“The USACE should reduce the volume of sand extracted from the Scusset site as mining more than 224,000 cubic yards could increase storm damage to updrift properties,” Ms. Engler wrote.
Mr. DeConto said he is worried that the CZM’s stance could affect the Army Corps’ plan to renourish the beach and could set the tone for other state environmental regulators who will issue—or withhold—permits for the work.
Michael S. Riccio, the Army Corps’ project manager for the New England District, said in an email yesterday that the Corps is aware of the CZM’s concerns.
“We are working directly with CZM to help address their concerns and reach a mutually agreed upon solution,” he wrote. “We don’t have any substantive updates beyond that at this stage, but it’s safe to say that we’re actively engaged with CZM to help solve this problem quickly and effectively, so that we can get this project across the finish line while minimizing impacts to the environment and surrounding area.”