Tisbury Great Pond opened to the sea
Updated: Jan 8, 2019
Jay Sonia, owner of Brickstone Construction, pulled the plug on Tisbury Great Pond in March and I was there to witness it. Sitting at the controls of a Deere excavator on a freezing Sunday, the cab wrapped in plastic a la Salvador Dali (I’ll get to that), he took one bite after another out of the sandy barrier beach and over the course of several hours dug a channel from the Atlantic Ocean to the pond. With one final bucket scoop, Jay released a torrent of pent up pond water, bringing a measure of relief to surrounding homeowners with wet basements.
Under normal circumstances, I would not have visited the opening when the temperature, adjusted for wind chill, was minus 40 degrees. I prefer to be at the opening when striped bass and bluefish are converging on the bait flowing out of the pond and I can avoid hypothermia.
On this occasion I was trying to catch a story for WCAI, the Cape and Islands NPR station. While at the station recently to do an interview on my new book, "Martha's Vineyard Outdoors," I was asked if I would like to do some reporting on Island stories.
I said that would be fun. They handed me a tape recorder, microphone and headset. With no prior experience in radio I thought the opening would provide a good trial run.
Although the pond is generally opened in April, a succession of winter storms brought heavy rains and raised the water level as high as many longtime pond watchers had ever seen it. The overflow flooded surrounding basements, fields and roadways.
I meet Kent Healy, civil engineer, West Tisbury selectman and one of three pond commissioners at the beginning of Quansoo Road. Jay Sonia showed up with his machine on a flatbed truck and off we went down the long dirt road to Black Point. We passed many fallen and broken trees, casualties of the most recent storm. Under normal circumstances we would have accessed the beach through Quansoo but because the pond was so high the parking lot was flooded and the creek was impassable.
When Jay arrived at the Black Point Beach parking lot he jumped out of his truck and began swearing a blue streak. He was very upset. Along the way an overhanging tree had just caught the cab of his excavator. The cab was seriously crunched and its windows smashed.
He was definitely not in a good mood. I thought better of asking him for a quick radio interview.
But Jay was resourceful. He connected a chain to the cab and attached the other end to a tree and proceeded to wrench the cab supports back into reasonable enough shape so he could climb into the cab — a combination of Stone Age fury and modern machinery made it usable. Then he drove the clanking beast across flooded Black Point creek and headed east along the beach.
I followed — a mile and a half walk in neoprene waders! Anything for a story.
I give Jay lots of credit. He got to work. With no cab windows for protection, he was exposed to the full brunt of a freezing northwest wind blowing about 25 miles per hour.
But West Tisbury herring warden Johnny Hoy, who had traveled across the choppy pond in his work skiff, was Johnny on the spot. When he saw the damaged excavator cab he left and shortly returned with a roll of plastic wrap. Armed with a roll of duct tape, rope and Island ingenuity, Johnny and Jay wrapped the cab and created makeshift windows that offered some degree of shelter.
Johnny had asked Jay to make the cut as deep and as wide as possible to create a strong initial flow. Jay did his best. Ideally, the opening will last so the herring return en masse this month can enter the pond.
Johnny said herring are “under duress” and he is determined to do whatever he can to help the fishery. “Herring are a big part of the food chain and we’ve got to do our part to keep it ticking the way it’s supposed to be,” he said.
Johnny, a fisherman, stonemason and lead singer of the well known band, Johnny Hoy and the Bluefish, finds herring beautiful. He recalled a moment last year when shovels were used to reopen the narrowing cut. “The herring were just charging up after that first trickle let go, just a mob of them, and they were beaching in their excitement to get up that trickle — it’s just life itself — they’re just following those age old instincts to go spawn and it’s good to help.
Tisbury Great Pond is fed by streams, groundwater and rain. It is opened approximately four times a year to the ocean. The flushing action and the resulting tidal exchange raises the salinity level of the 700 acre waterbody, which is beneficial for shellfish, white perch and herring.
A week before Tisbury was opened, the adjoining Chilmark Great Pond was opened, as was James Pond on the north shore where Johnny has been working hard to re-establish the James Pond herring population.
Islanders have been opening the great ponds for centuries. The first recorded date is 1715. Mrs. Johnson D. Whiting rented a team of horses and a driver for $1.85 to open Tisbury Great Pond.
Kent said generally the pond is opened when it is about three to four feet above sea level “so you get a good flushing action.” On that day he said it was four to five feet above sea level.
Asked how much water he estimated would drain once the pond was opened, Kent, a former professor, provided a math problem for this unwilling student.
“Well, the area of the pond is 26 million square feet. If we lower it four feet this time than that’s about one hundred million cubic feet. Multiply that times seven and a half gallons per cubic foot and you’ve got the number.”