Archive for December 11th, 2012

Dec 11 2012

The Big Dig of Cotuit is Coming

Word is circulating around the village of an application by Three Bays Preservation and the Massachusetts Audubon Society to dredge away a big piece of the western, Cotuit end of Sampson’s Island and pump the spoil back to the eastern, Osterville end of the barrier island. While details were sparse and everything was hearsay when my source phoned to see if I had any specifics, an email to Three Bays Executive Director Lindsay Counsell  cleared things up.

LGCotuit1952 copy (1)(click the image for a sense of how wide the Cotuit channel was in the 1950s)

The application will go before the Barnstable Conservation Commission on January 8. It’s available along with detailed engineering plans and maps  at the Three Bays website. Here is a link to the specific project application.

Counsell wrote to me:

“Three Bays and Mass Audubon are proposing to dredge the end of Sampson’s Island and we both will be presenting the project at the Jan. 8th Con Comm hearing.  The footprint of the work area is 11 acres and the material will primarily be transported easterly to Dead Neck, with several areas on the beach nourished for coastal waterbird nesting habitat and a recreational beach segment is also proposed.  This channel area to be altered comprises the original permitted dredge footprint that has been maintained previously since the before the1940’s and it is for that reason we are seeking renewal of those permits.  This project proposes to back pass the sand easterly from its origin and close the loop on the local littoral drift cut off in 1900 by the creation of the West Bay Cut.

This is a joint application of the two owners of the island and we are going forward based on the need to rebuild Dead Neck with material that has drifted down shore to Sampson’s Island.  The island’s bird nesting habitat is almost completely gone through erosion and vegetation infill and active construction and maintenance thereof is the only feasible method to recreate those areas.  Other interests the project serves are storm damage protection, navigation, public safety and to a lesser extent water quality improvement.”

 Three Bays came to Cotuit a couple summers ago to drum up support and raise money for the project. I wasn’t able to attend, but understand from some friends who did go that the pitch met with some skepticism — some Cotusions reacted that the plan sounded like a plan to take their money and “their” sand to fund a beach replenishment project for the other, Osterville-end of the island. Three Bays is (and has long been) a big advocate of dredging as a way to improve the flushing of the stagnant, overly fertilized water high in the estuary. This isn’t dredging for the sake of improving navigation and making the channels deeper so bigger boats can enter and exit the bay. This is about opening things up so the sclerotic system can purge itself faster with the tides.

This isn’t the first time Three Bays has dredged to improve circulation. The last came about decade ago and did indeed improve the internal channel system and put a lot of sand back on the beach near the Wianno Cut — the man-made entrance to Osterville’s West Bay.

The spit is thinnest there and despite several expensive projects to build the beach back up — including one crazy privately funded endeavor that used a helicopter to ferry hopper after hopper of sand from inside the island to the outside beach — it remains the most likely spot for a beach breach during some future storm. Three Bay’s application predicts a breach of the beach within five to seven years, exposing the Seapuit River behind the island to the full flow and force of Nantucket Sound.

Piping 11 acres of sand, grass and mud from one end to the other will definitely shore things up, and will solve the growing encroachment of the western end of the spit into the main Cotuit Bay channel. Old photos and postcards taken in the 50s and 60s from Cotuit’s Loop Beach on Nantucket Sound looking inland, towards the island, show a very wide channel with the point of the island back at last a quarter mile from where it is today.  The gap was once so large that a person standing at Loop could look to the northeast and see nothing but water all the way inside to Oyster Harbors/Grand Island.

This project would give Sampson’s a serious trimming. Here is a detail of the plan showing the proposed cut line as well as some of the areas due to receive new sand. Click the thumbnail for a bigger view.

The sand would be pumped to a few spots on both the inside and outside (Nantucket Sound) sides of the island.

The project is an attempt to patch the damage did at the turn of the 19th and 20th centuries when the Wianno Cut was dug through Dead Neck (“Neck” being a Cape Cod geological term referring to a sandspit that attaches to the mainland). At that time Dead Neck ran west from Osterville, in front of Oyster Harbors, and behind it, to the north, ran the Seapuit River, then the only channel draining Osterville’s West Bay. Sampson’s Island lay to the west, separate from Dead Neck.

The Cut project was opposed by the residents of Cotuit, including my great-great-grandfather, who led the opposition to the dredging on the grounds it would disrupt the natural flow of the estuary. The commercial interests in Osterville prevailed. The boat building industry at Crosby’s doubtlessly needed better navigational access and Cotuit at the time was a busy commercial port serving Nantucket with firewood, freight and the mail. Two stone breakwaters, or jetties were built on each side of the Cut by the state and they are the reason more than 100 years later dredges and helicopters are needed to restore the natural equilibrium of sand nourishment along the beach. In essence the jetties blocked that sand, trashed the natural equilibrium, and the result is a drastically changed landscape.

I think it is safe to say that no one is proposing to dismantle the jetties and plug the Cut. Instead we’re faced with chewing off 144,000 cubic yards of sand, mud, grass and clams and blowing them through pipes onto the starved sections. Given the sad fact that recent dredging has proved to be a bit of a Sisyphean battle, with one project’s efforts getting washed away by the next big storm or two, this one is not going to be a definitive solution and will buy a decade perhaps of protection to the nice houses behind the eastern end of the beach.

I’ll anticipate the oppositions’ and the proponents’ arguments then weigh in with my own opinion:

Against:

  • Don’t mess with nature and let things take their course. Let the island breach.
  • Don’t cut down the copse of mature trees and shrubs to the east of Cupid’s Cove that is proposed on the dredge map -probably by Massachusetts Audubon (co-owner of the island along with Three Bays) — for “predator management. Dead Neck/Sampson’s Island is a key bird sanctuary in the Mass Aubudon system of refuges, especially for Arctic and Least Terns and various critters from skunks, raccoons and even coyotes have been swimming across Seapuit to snack on eggs and fledgling birds.
  • The silt and turbidity this will create will raise hell with the shellfishing and the aquaculture grants owned by the Cotuit Oyster Company, Conrad Geyser, and the commercial aquaculture project inside of West Bay.
  • It erases a very very popular summer sunbathing beach on the Cotuit end.
  • Why not dredge the main channel that was last dredged in 1944 by the Army Corps of Engineers for Camp Candoit and dredge where it will do some good?
  • This is Osterville versus Cotuit

For:

  • The point of the island has grown unnaturally close to the Cotuit shore and is causing a hazard to navigation in and out of the bay.
  • This will dramatically improve flushing and could lead to a restoration of eel grass beds inside of the island and a possible return of scallops, etc.
  • A beach breach into Seapuit could potentially close the river to navigation and open up the waterfront of Oyster Harbor to the full force of Nantucket Sound in a storm.
  • The Cut is an unnatural disruption in the natural order and beach sedimentation processes so man made measures are called for.
  • The point of the island was historically back at the cut off point shown on the map.
  • Dredging will take place in the winter months to cut down on adverse effects to the shellfish which spawn in the summer.
  • The birds are endangered and need all help they can get in terms of optimal nest sites and reduced predators.
  • It’s all one interconnected system so Cotuit vs. Osterville or Osterville vs. Cotuit is silly.

Me? I’ve seen the old photos and know the Cotuit end used to be much wider, so this isn’t an unnatural proposal. I’ve grown accustomed to the current configuration and would very much miss the cove that would all but disappear as a place to anchor my boat on the weekends.  While I can grumble and point fingers at the idiocy of past generations in trashing the beaches with their jetties, groins and Cuts they’re all dead and there’s no undoing the damage, lord knows the current generation sealed the fate of the bays when it permitted the Rape of the Cape to happen from 1970 to the present. I doubt this is going to magically clean up the water quality — we simply don’t have the tidal range to get a big transfer of water through the system, big channels or not, but it can’t hurt. So, I’m in favor but think it’s yet another sign of the times, there’s no going back to what we’ve lost, but there’s no reason to give up hope. And heck, I’ve seen the old plans from the 1920s to build a polo field and landing strip for airplanes on the island, so at least we’re not dealing with that.

Here are some old charts showing the changes to the beach over the years. First, from 1857:

This is pre-Wianno Cut. West Bay in Osterville drains through the Seapuit River and empties into Cotuit Bay and out through a gap between Dead Neck and Sampsons Island, then truly an island.

Now 1933. Thirty years after the Wianno Cut was built. Sampson’s has bonded to Dead Neck and the old channel is closed, forming Cupid’s Cove. The western end, the Cotuit channel, is very wide:

And finally, a Google Earth satellite photo of where we are today.

disclosure: I am a paid member of both Three Bays Preservation and Massachusetts Audubon and think they both do good work. I was a volunteer water quality tester for Three Bays last summer.

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