A typical section of a groin (or jetty) from “Proposed Shore Protection Provincetown,” September 1939, Division of Waterways, Department of Public Works of Massachusetts. [Provincetown Building Department / Colors, textures, and waves added by ChatGPT]
Two groins in the East End. [2010, Dunlap]
Updated on 18 January 2021 | Like the giant teeth of a sand comb, a series of 26 stone jetties — more accurately called groins — rake the beaches of Provincetown Harbor. They were constructed from 1939 to 1940 at a total cost of $30,000 (about $550,000 in today’s money). The Town chipped in 25 percent. Barnstable County and the Commonwealth of Massachusetts picked up the rest of the tab. The East End groins were built first, by Louis Byrne of Dennis. The Speedway Construction Company of Boston built the second group, in the West End. Each was originally 125 feet long, 12 feet wide, and 3 feet high. Many of the stones used for these groins came from Quincy, which was the source of the boulders used in the enormous West End Breakwater.
Groins are designed to mitigate the drift of sand along a beachfront. As far as their many critics contend, they do their job all too well. They create curving pockets along the shoreline as sand erodes from the leeward side of one groin and is deposited against the windward side of the next groin along. There are other perils, according to the Provincetown Harbor Management Plan Amendment of 2018. “Groins become navigational hazards when they become submerged at high tide,” the plan stated. “Proper marking can prevent accidents.”
To the extent they have preserved property owners’ beachfronts, however, the groins are considered a success.
“Without them, a lot of houses and buildings along Commercial Street would soon be gone, because their exact purpose is to stop the natural erosion of sand,” the fisherman Wayne Martin said in a Facebook post on 17 January 2021. “Look what happened to Herring Cove right after they removed all the ones that were there. Did you think they were placed there because they were aesthetically pleasing, or for little kids to climb on? Also, what type of vessels travel that close to shore along that stretch of beach at a rate of speed that it would be considered to be a ‘navigational hazard’? To do so would be idiotic, not to mention illegal.”
Locations of some groins
• 25 Commercial Street
• 51 Commercial Street
• 61 Commercial Street
• 183-185 Commercial Street
• 467 Commercial Street
• 519 Commercial Street
• 535 Commercial Street
• 545 Commercial Street
• 557 Commercial Street
• 575 Commercial Street
• 593 Commercial Street
• 603 Commercial Street
• 617 Commercial Street
• 631 Commercial Street
• 643 Commercial Street
• 657 Commercial Street
• 667 Commercial Street