[zacs]

All Eyes On South Beach Washover
If Permanent, Impact Could Be Significant, Officials Say

by Tim Wood <mailto:twood@capecodchronicle.com>

CHATHAM - With the sun shining and temperatures finally reaching above freezing, Sunday was a great day for a walk. For Shellfish Constable Stuart Moore, it was an opportunity to check out the reports he’d heard earlier in the week of a significant washover on South Beach.
He’d seen something through his binoculars from the mainland and was anxious to check it out, but with local harbors iced in, he decided to hike out to the spot on his own. It was high tide by the time Moore reached the location of the washover about two miles south of Lighthouse Beach. Water was flowing freely from the Atlantic into the South Way between South Beach and North Monomoy Island.
“It’s a big washover,” Moore said Monday. “There were a lot of places where it had washed over during the storm, but this was the only one I saw that was continuing to wash over. It’s a big hole.”
Caused by the heavy seas and up to 70 mile per hour winds during last week’s blizzard, the washover appears about 100 feet wide at high tide but is dry at low tide, said Moore . Whether the big gash in the barrier beach will be permanent, and what long-term ramifications it might have, remain to be seen.
“It could be a significant change on the way for the area,” said Coastal Resources Director Ted Keon.
The blizzard also impacted other areas of the shorefront, particularly the beach at Andrew Harding’s Lane, where all of the sand pumped there as beach nourishment by the Barnstable County dredge last fall was washed away. There is also concerns that continued washovers at a narrow section of South Monomoy Island could lead to a permanent break there.
As of Tuesday, Monomoy National Wildlife Refuge Manager Mike Brady had not had an opportunity to view the area, about the island’s midpoint, a section known as the Overwash. It also washed over during the major snowstorm in December. If South Monomoy breaches, there are both positive and negative ramifications, he said.
“If that does break, not only will there be more clam flats available, there will be more shorebird habitat,” he said. A break would create a fan effect of sand on the west side of the island, creating habitat conducive to species such as oyster catchers and terns, as well as soft-shell clams. However, it will make the logistics of managing the island and its shorebird population more difficult, requiring that personnel be shuttled back and forth to what would be a new “south” South Monomoy Island .
Brady was philosophical about the possibility. “It’s a natural geological function of these barrier islands.” The washover isn’t unexpected; scientists say that South Beach will gradually migrate west by storm, wind and wave action, connecting at some point to Monomoy and melding onto the mainland in the Little Beach and Morris Island areas.
It’s all part of the Nauset Barrier beach process, which began in 1987 when a northeaster punched a hole in North Beach opposite Lighthouse Beach. That break, which began as a breach about the size of the newly discovered washover, became the current Chatham Harbor inlet, which is more than a mile wide. A similar northeaster in February 1978 split Monomoy into two islands.
Asked how the washover on South Beach could impact North Monomoy , which is directly to the west, Brady said he didn’t think it would be that significant, even if it becomes permanent.
“ North Monomoy has seen a frontal assault before, before South Beach was there,” he said. However, a permanent break in South Beach could hasten the attachment of the severed southern section of the spit to Monomoy; there is a lot of sand between the two barrier beaches, and if the tidal flow is diverted through a new break, the opening to south could fill in more rapidly than might otherwise happen, Brady suggested.
That would raise the issue of who has jurisdiction over the newly connected beach. Currently, South Beach is within the jurisdiction of the Cape Cod National Seashore, and is owned and overseen by the town. The U.S. Fish and Wildlife Service would likely claim jurisdiction if it attached to Monomoy, Brady said. The issue is currently being studied as part of the comprehensive conservation plan for the refuge.
One immediate impact of the South Beach washover is the loss of a significant amount of productive clam flats, which were buried by sand washed off the beach, said Moore . “It’s a well-fished area,” he said. “What that’s going to mean, who knows. Short term, it’s probably nothing good.” He said he was told by shellfishermen that a significant amount of sand “got moved around” on the clam flats west of Monomoy as well. It generally takes a while for new clam habitat to develop after a break or washover; it was several years after the 1978 Monomoy break before flats on the west side of the island became the town’s most productive shellfish resource, now worth millions of dollars a year.
About 10,000 cubic feet of sand pumped onto the beach at Andrew Harding’s Lane in the fall was mostly washed away by the storm, Keon said. The biggest impact was at the foot of the road, where the beach and dunes were peeled back to where they were prior to the nourishment. Keon wasn’t surprised, noting that the sand was put there as a buffer to prevent even more severe erosion.
“But it disappeared disappointingly faster than I’d hoped,” he said. “Right now it’s pretty thin.”
Other areas hit hard by erosion during the storm were the Strong Island and Scatteree town landings, said Keon. There is also concern that there may have been major damage to North Beach in a narrow area across from Minister’s Point. As of early this week, the deep snow and harbor ice had kept anyone from getting to the beach for a first-hand look, according to William Hammatt, chairman of the town’s North Beach management committee and a camp owner.
“We were thinking of asking if we could take a snowmobile out,” he said.