Ebb and flood in Farm Pond
Slowly, carefully, Danny Rogers slipped a tooth on the end of his small excavator's scoop bucket between the five-foot culvert and the large concrete plug that has blocked it for the past 25 years. Gently, he pried the circular plug away from the culvert that connects Farm Pond with Nantucket Sound.
A trickle of water was already seeping out. The other end of the long closed culvert, on the Farm Pond side, was opened a few minutes before. The few hardy souls gathered in a stinging cold rain were expecting a giant whoosh of water when Mr. Rogers lifted the concrete plug out of the way. But the dramatic moment revealed... a whole lot of sand.
No one is quite sure whether sand was pushed into the culvert when it was plugged up in 1984, or whether sand migrated into the culvert through small openings around the concrete plugs, but there was a lot of sand, and almost no water flowing from Farm Pond into the ocean.
Mr. Rogers scooped as much as he could reach with his excavator, and then Oak Bluffs shellfish constable Dave Grunden crawled inside the culvert and began to shovel by hand. But more digging didn't open the culvert. Finally, the crew decided to rely on the same force of nature that has so radically altered this stretch of Vineyard shoreline over the last 50 years - the tides.
Sure enough, with an astronomical high tide later that evening, the water pushed the remaining sand out, and the tide began to flow through the culvert at a swift clip.
"It's a feeling of success," Mr. Grunden said. "We took a step toward the end goal of getting the pond restored. It was great to see the water running."
Constant tidal erosion, accelerated by battering storms, has radically changed the shoreline opposite Farm Pond, and those changes have mostly caused harm to the salt pond by closing off the outlets to the ocean. Where once there was an acre of sandy beach, now there is none. The culvert that was opened last Thursday was plugged up because it emptied out onto the only stretch of sandy beach left in the 1980s. At that time, a new culvert was installed further up Sea View Avenue toward Oak Bluffs. That culvert remains open.
Getting permission to unplug the old culvert was no simple task. Mr. Grunden said it took 19 months to secure all federal, state, and local permits and permissions necessary. Signing off was the Army Corps of Engineers, Massachusetts Coastal Zone Management, the Massachusetts Department of Environmental Protection (twice), the Massachusetts Division of Fish and Wildlife, The Massachusetts Division of Marine Fisheries, and the Oak Bluffs Conservation Commission.
Farm Pond has been closed to shellfishing since 1985, because of consistently high counts of fecal coliform in the water. Recently, a scientific identification method called ribotyping identified geese as the source of bacterial contamination in 16 of the 19 water samples taken from Farm Pond.
Coastal Zone Management, which lists Farm Pond as a priority project, determined that culverts totaling 16 feet in diameter would be the optimal size for tidal flushing. Tides now flow through two culverts, with a total opening of eight feet. That won't restore Farm Pond to prime health. "Opening the culvert is a Band-Aid," Mr. Grunden said. "It's a step in the right direction."
Once, farm pond yielded a bounty of blue crabs, soft shell clams, and oysters. Reopening the pond for shellfishing is one of Mr. Grunden's goals. With the additional circulation, he hopes that it will be declared a conditionally approved area, which means it will be open for shellfishing in the winter only.
But work continues to improve the water quality of Farm Pond. Mr. Grunden credited the Friends of Farm Pond, and neighbors in the Harthaven community for their persistence. But he said it will take much more work. "It's an ongoing project, and will be going on for years," he said.