CHATHAM – Cockle Cove Beach has seen its share of erosion in the past decade, but last month, for the first time, storm-driven waves claimed a section of the town beach's parking lot. The storm also breached a dune and sent water from Nantucket Sound into the marsh behind the beach.
Cockle Cove is “probably the foremost hot spot we have, with some of the highest erosion rates along Nantucket Sound,” said Coastal Resources Director Ted Keon. But it's not the only southside beach to see the effects of erosion. To the east, high tide often reaches the dune line along Harding's Beach, in some areas leaving little beach at high tide.
Harding's is the town's most popular beach, and along with Cockle Cove and three other public beaches represent not only top tourist destinations but also a significant revenue source, taking in $225,700 in nonresident parking fees this past summer. Harding's Beach accounted for more than half of the revenue, which Park and Recreation Director Dan Tobin said was lower than usual this year due to the weather.
Protecting those assets from further erosion will take a significant amount of money and a multi-year commitment, Keon told selectmen last week. Dredging sand to nourish both Cockle Cove Beach and Harding's Beach will cost about $750,000 and have to be repeated every five to seven years, he said. Because it's in the worst condition, he recommended Cockle Cove Beach be nourished next year at a cost of $450,000, with Harding's Beach following in fiscal 2020 at $300,000. Cockle Cove should be on a nourishment cycle of approximately ever five years, with Harding's Beach nourished every seven years.
Selectmen unanimously backed the development of a beach nourishment program for Nantucket Sound and directed Town Manager Jill Goldsmith to include the funds in next year's budget.
“These are assets that we need to preserve and protect, and defend” the town's coastal assets, said Selectman Jeffrey Dykens.
Situated at the easternmost end of Nantucket Sound, Chatham is in a “somewhat unique geographic location,” Keon explained. Sand along the Cape's south shore travels west to east, but sand lost from Chatham beaches is not being replenished by sand from the west because the flow is interrupted by dozens of man-made jetties which trap material and keep it from reaching the eastern end of the system.
“Very little if anything gets around the Red River jetty system to begin the nourishment of Chatham's beaches,” he said.
Over the years, the town has used sand from navigation dredging projects at Mill Creek and Stage Harbor to periodically build up Nantucket Sound beaches. The volume of material available through those projects, however, “is insufficient to offset the erosion that's going on at those beaches,” Keon said.
Fortunately, Chatham has other sources of sand. In order to obtain the 30,000 cubic yards needed to build up Cockle Cove Beach and the 20,000 cubic yards Harding's Beach requires, Keon proposed creating a channel in the Morris Island cut, between Morris Island and North Monomoy, which offers an almost unlimited supply of material.
The massive movement of sand caused by breaks in South Beach has clogged the waterway with shoals, causing navigation problems last summer. While the town hasn't dredged there in the past, the area is included in the comprehensive dredging permit the town obtained a few years ago, and Keon suggested the permit could be amend to increase the width of a channel from 75 to 100 feet. It may be possible to get more than 40,000 cubic yards of sand by dredging, working with the natural currents to put a channel where it works best.
“This is a great source of sand,” he said, but given the highly dynamic nature of the area, “the channel longevity is going to be very unclear.” It's a double-edged sword, he said; there's plenty of sand available, but the dynamic nature of the area means a channel dredged in the winter or spring may not be there a few months, or week, later.
While perfect for nourishing Harding's Beach, the Morris Island area is a long way from Cockle Cove Beach, and would require that the Barnstable County dredge, which would be less expensive than a commercial dredge, use a booster pump, which increases costs to $13 per cubic yard. The town may have to purchase more pipeline to span the 12,000- to 14,000-foot distance, he added, but the county has just purchased a second dredge with longer pumping capabilities.
“We are anticipating the new dredge will probably be able to pump” the needed distance, Keon said.
If the funds are approved at May's annual town meeting, because of environmental restrictions dredging would take place between September and March, if the town can get on the county dredge schedule.
Cockle Cove clearly merits immediate attention, Dykens said. “I feel we're a little behind the eight ball,” he said. Keon said the town requested dredging of shoaling at the mouth of Mill Creek last year, but it didn't make the county dredge schedule; that sand would have gone to protect Cockle Cove Beach. Truckloads of sand dumped at the edge of the parking lot over the spring and summer helped stem further damage, but were no match for the October storm.
“It is in the schedule for this current dredging season,” Keon said, and will likely be done sometime after the new year.
Selectmen agreed the situation is critical. Chairman Cory Metters said he grew up in the Cockle Cove area. “I know all too well how this area's changed over the years,” he said. The nourishment program is “something we really, really have to do.”
Selectman Dean Nicastro said the project was “essential,” but said the funding will have to be weighed alongside other capital spending requests.
With apparent ongoing dredging needs, Selectmen Amanda Love asked why the town doesn't purchase its own dredge. Given the ongoing personnel and maintenance costs, that wouldn't be cost effective, said Natural Resources Director Robert Duncanson.
“We have a lot of dredging needs but not on a continuous basis,” he said. That's why the county purchased a dredge in the first place and is acquiring a second, because among Cape towns it remains busy almost year-round. “That's probably more cost effective than us buying our own,” Duncanson said.
Selectmen voted to support the nourishment plan and its funding as well as the concept of obtaining sand from the Morris Island cut. With climate change, sea level rise and worsening coastal storms, the town need to stay on top of the situation, said Dykens.
“Cockle Cove's a mess. I don't think we can let this get away from us ever again,” he said.